The level categories for Alice (............) and B (..............) mean that the ......_........ relation between these level categories does not hold.

the last of the three forms of the .................. relation determines that Alice s clearance category is .............., and that an information flow can flow from the category .............. to the category ...............


For the casethatpriority score.r =.l , the exploration follows the natural execution choice.

iCE will remember the decisionpoint andgoback to explore the otherbranchlater.


Intuitively, in the above construction we create a random salt k1 from a small subset of the keyspace (those with a .xed pre.x) and use this salt in the password hash as before.

we do not store the salt in plain, but give a ciphertext/plaintext pair that identi.es it.


Regardless of the capabilities of the Pi, our testing results reveal that there are still many problems associated with it depending on the attack methodology.

most of these issues can be solved with more money.


The data model underlying our security meta model is optimised for administration; this will have a negative impact on the performance of the operative access control decisions: The data needed for the access decision must be collected from di.erent sources and combined at run-time.

a representation of authorisation data optimised for performance would be di.cult to handle by human administrators.


An attacker could overwrite a data pointer directly, which is similar to the previous attack, and can cause some computation to be done on a location of his choosing, rather than the intended data.

unlike the previous attack, an absolute location in memory is chosen, this will directly reveal where code is and what changes have been made to the code.


This privacy notion is not safe if some sensitive values dominate an equivalence class.

our proposed approach can achieve anonymity, con.dence bounding [15], (a,k)-anonymity [16], and other safer notions of .-diversity [8].


Ruby on Rails with the SimpleForm plugin [16] allows a developer to write the constraints that data should satisfy on the server, and enforces those constraints on the client.

it only supports a handful of built-in validation routines and fails to factor in constraints encoded in HTML form .elds that depend on server-side state.


Table 5: JitterBug test scores Figure 6: EN test scores for JitterBug LEGIT-SSH JitterBug test mean stdev mean stdev KSTEST .270 .133 .273 .123 regularity 6.230 5.847 6.038 5.624 EN 19.422 1.856 9.432 1.253 CCE 1.779 0.261 1.837 0.220 Table 6: JitterBug detection rates LEGIT-SSH JitterBug test false positive true positive KSTEST = 0.63 .01 .01 regularity = 0.08 .01 .02 EN = 21.20 .01 1.00 CCE = 2.17 .01 .04   4.3 Discussion The detection tests that we present are all able to detect some covert timing channels under certain conditions.

the previous methods fail for detecting most of the tested covert timing channels.


emulate real hardware more faithfully so that unmodi.ed kernel binaries can be used.

the more realistic level of simulation that is desired from the VMM, the slower the simulation will be [10].


Atimegap between the test and the training data sets might make it harder to de-anonymize the data, because the common content between the test and the train sets decreases with time.

prior research[20]showsthat userstendtoposeexact samequeries overandover,asitis easier comparedto rememberingtheurlofthe search result, or more ef.cient than performing an internal search within the website.


Other traditional modes of encryption, such as CBC and ECB, do not suffer from the vulnerabilities mentioned in this paper.

they need to be combined with other mechanisms in order to overcome structural analysis.


Briefly, self-adaptive security can be defined as the following capabilities of the system: i) System is capable to monitor its internal security state and external threat landscape in order to reveal possible security violations; and ii) System is capable to react to possible security violations and ongoing attacks by selecting alternative security mechanisms and parameters to keep the system on a secure state or move it back to the secure state.

recognising security violations requires correct and timely situation-awareness, which is built especially for the self-adaptive security purposes.


8.4 AndroidKeyStore on TI devices AndroidKeyStore on Texas Instruments devices also stores two .les in the /data/misc/keystore/user_0 directory for each key pair.

the actual contents of the private key .le is di.erent than with the Qualcomm implementation.


In such situations Delay Tolerant Networks (DTN) are used to disseminate the data by exploiting the peers mobility in the area.

existing DTN protection models require recipients to be known in advance.


as the virus attacks of 2003-4 continued, we developed a serious concern.


In FaceCloak, the fake information and a key that only the sender and all his contacts know serve to compute the index under which the third-party server stores the ciphertext.

our solution works solely with currently available services on the Internet and does not require dedicated infrastructure.


For the middle node the path selection proceeds as for the entry nodes except that middle nodes do not require speci.c tags.

all relatives of both the exit node and the entry node are excluded.


The attributes that can be negotiated in this phase include the protocol (AH or ESP), the authentication algorithm, encapsulation mode (tunnel or transport), encryption algorithm and Di.e-Helman group information.

iPsec is not applicable for securing NDP and the local link communications [4].


Enforcer [5] is a Linux Security Module (LSM) [3] that supports sealing and a form of certi.cate-based authentication that could be used in lieu of attestation.

enforcer is unable to prevent circumvention of distributors policies by recipient system administrators.


3.4 Manipulating Tag Data Blocking the RF might work for someone attempting to steal a single item.

for someone looking to steal multiple items, a more efficient way is to change the data on the tags attached to the items.


If out-of-band communication is used, this cost could be extensive.

if the PGV device is equipped with a trusted public key infrastructure, this cost could be reduced to simply performing encryption.


Previous works have already investigated the possibility to use the accelerometer as biometric authentication.

theyeither only considered secret movements the user needs to remember [15] (i.e.


One promising approach is to adopt a program as a communication channel model and leverage information theoretic metrics to quantify such information .ows.

recent research has shown discrepancies in such metrics: for example, Smith et.


This would allow the dentist to read all data concerning dental clinic visits, dental x-rays, allergies, and medications.

the dentist would have no way of decrypting any of the information in the patient s mental health records, or her cardiologic data, for example.


The last three solutions correspond to con.ict resolution by constraint relaxation.

relaxing a constraint in an arbitrary manner may produce signi.cant deviations from the original policy and may not yield optimal resolution.


One very attractive notion of privacy is perfect privacy a secret is expressed through a query QS , and a query QV is answered only if it discloses no information about the secret query QS.

if QS and QV are arbitrary conjunctive queries, the problem of checking whether QV discloses any information about QS is known to be .p 2-complete.


Similarly, P(6a+ln) is the second strongest area.

either P(Tn), P(la+6n) or P(2a+Sn) is a relatively weak Itrea where passwords are with low entropy.


With all the efforts in recent year for elliptic curve standardization, this covers: Message-based ECC encryption algorithms, PKI Standards, S/MIME, SSL/TLS and XML Signatures and Encryption, IPSec, PKCS#11.

there are still some works to be completed.


A static public key might be distributed openly, as part of a cryptographic software package, in which case it does not add any new risk of censorship; changing the encoding of the public key does nothing to hide the package from a censor.

if a client already has all necessary cryptographic software, and a server broadcasts a series of static public keys by encoding those keys inside otherwise innocent web pages or other cover tra.c, then indistinguishability from uniform is exactly the tool needed to defend those public keys against a censor with an accurate model of the cover tra.c.


In this approach, an organization shares access control information such as user-role assignments to other organizations in the federation while retaining its autonomy [1].

an identity-providing organization (IdP) might consider user-role assignments as critical and private information, and are unwilling to share this information with a service-providing organization (SP).


al proposed µTESLA [19] protocol for source authentication in data dissemination through lossy channel.

µTESLA requires global loose time synchronization which is di.cult to apply to reprogramming wireless sensor networks.


Without packet payload data, we cannot determine with certainty which of these connections carry HTTP tra.c.

based on the port numbers they use, 15 of them, all on TCP port 8080 at the anonymized IP address 128.3.148.116, probably are in fact HTTP.Figure6(a) shows one such connection.


These analyses track stronger dependencies than those induced by explicit .ows; in particular, the dependencies are sensitive to control .ows.

the use of explicit substitutions to track explicit .ows seems rather obvious and appropriate in hindsight.


Analysis of Virtual Machine System Policies Sandra Rueda, Hayawardh Vijayakumar, Trent Jaeger Systems and Internet Infrastructure Security Laboratory The Pennsylvania State University University Park, PA, 16802 {ruedarod,huv101,tjaeger}@cse.psu.edu ABSTRACT The recent emergence of mandatory access (MAC) enforcement for virtual machine monitors (VMMs) presents an opportunity to enforce a security goal over all its virtual machines (VMs).

these VMs also have MAC enforcement, so to determine whether the overall system (VMsystem) is secure requires an evaluation of whether this combination of MAC policies, as a whole, complies with a given security goal.


If we were to use a different constrained channel or use an IR receiver rather than a webcam, we could increase the transmission rate and speed up the protocol while maintaining the same security level.

these other options require additional hardware for the laptop, a requirement that contradicts some of our initial design goals.


This inherently means that information sent cannot be modi.ed, and that the consignor is authentic.

con.dentiality requires that sensitive information must not be leaked to an unauthorized party.


For example, to identify an HTTP-based attack called DNS-tools (CVE-2002-0613), which enables attackers to modify DNS entries, Snort [32] checks whether the network tra.c contains the string dnstools.php .

not all tra.c that contains this string is a real DNS-tools attack.


We call this feature as fmaxRepresent and add it into KIP F S.; 3: Delete all IP F Si which contains fmaxRepresent from FIPFS; 4: If FIPFS is not empty, go to step 1; 5: return KIP F S; C. Finding the Key IPFS Algorithm To protect data privacy, one natural way is to anonymize all possible features which could infer or directly release sensitive information.

it inevitably degrades the following data analysis due to the information loss caused by the data anonymization techniques.


(ii) All the nodes in the network are always moving within the area.

in reality, the majority of private cars show the occasional movement patterns (e.g.


FIREDROID POLICIES FireDroid enforces security policies for controlling how processes execute system calls.

specifying security policies at the level of system calls is quite a tedious task.


3.2.1 CSS String Injection One might expect that an HTML document, when parsed as a style sheet, would produce nothing but syntax errors.

because of the predictable error recovery rules described in Section 3.1.3, it is possible to inject strings into a document that will cause the CSS parser to come out of error recovery mode at a predictable point, consume some chunk of the document as a valid rule, and then return to skipping.


Manitou s use of execute bits prevents unauthorized code from ever executing a stronger guarantee than SBCFI.

the approach, as proposed, only enforces that valid code pages are executed, not that execution proceeds according to a valid CFG; this is similar to the .rst validation option presented in Section 3.2.4, and will miss at least some jump-to-libc -style attacks, even persistent ones.


Currently, most of these approaches attempt to prevent web exploits on the server side [29], by inspecting and employing sanitization checks on the data exchanged between the web server and the browser.

server side mitigation is not adequate for e.cient protection against all categories of web exploitation, and therefore protection mechanisms need to be also applied on the client-side (i.e., the web browser) as well.


that are absolutely necessary for malware attempting to perform a speci.c task to declare (e.g., SMS trojans must ask for SMS permissions, or their malicious code simply will not run).

if new classes of malware attempt to abuse other protected or unregulated [36] inter 4We exclude these apps from malware counts throughout the paper.


Naively, we can keep unfolding recursively-de.ned function replaceAll, until we can decide if the current formula is satis.able or not.

we provide reduction rules (unfolding on demand) for them instead.


In other words, each requester should receive a 1 share of the available nm +ng request channel ., regardless of whether that node is an attacker with a high request rate or a legitimate node with a low request rate.

even with any reasonable fairness guarantee, the time required to establish a setup packet is still necessarily dependent on the total number of users (nm + ng) and the amount of network capacity available.


Therefore considering network traces for worm detection is not a suitable choice.

host based approaches identify worms on the basis of their payloads responsible for carrying out malicious attacks.


Many of the faculty desiring to implement new curriculum, whether it be a single course, or an entire set of coursework may be eminently qualified to do so.

the uniqueness of the information security subject area requires a detailed understanding of the material that may not be prevalent in many institutions.


Speci.cally, the capture threshold model leads to binary con.ict relationships among the wireless links (i.e., any two links either interfere with each other, or they can be active simultaneously, regardless of the other on-going signal transmissions).

under the additive interference model, even though a set of links may each not interfere with a given link, they could still collectively cause a collision.


~ Standard mechanisms, such as access control and encryption, are essential tools for ensuring that sys- tem components do not violate these security policies.

for systems that contain non-trivial computational components, ac- cess control and encryption are much less helpful for ensuring (and proving) that the system obeys the desired security policies.


We can restrict the shared secret x to be standard user passwords, and aid the user by performing a·x one-character at a time, displaying the results in a similar grid-like structure.

unlike the GridCode, the response bit depends on the position of each character in the password, e.g., is a the .rst character, second character, etc.


The HE-based schemes, on the other hand, achieve a performance of N K asymmetric cryptographic operations, compared to 4N K £2/o symmetric cryptographic operations in GSHADE.

asymmetric cryptographic operations, i.e., modular exponentiations, are usually several orders of magnitudes slower than symmetric cryptographic operations such as AES or SHA, especially when increasing the security parameter.


Lampsonwasthe .rsttodescribe access control matricesas a framework for teaching and reasoning about access control [4].

lampson was not concerned with user interfaces, and so did not discuss how access control matrices could be used interactively to author policies.


Indeed, there is potentially a large number of states, including many states that will never be reached, especially in the case of AC-PODMPs, since the policy needs to be calculated for each possible state distribution.

calculating the optimal policy for a particular state can be too complex for systems with limited resources, such as mobile devices.


In particular, with a limited number of training data, it is unsurprising that the CNN engine will decrease our attack s success.

interference arcs marginally contribute to the security of this scheme, too.


3.3 Cache control directives For cache-based privacy attacks on non-cooperative sites, timing attacks may be the only available option.

for semi-cooperative tracking, there is no reason to resort to statistical techniques.


As an example, mechanisms that protect out-of-bounds accesses, such as AddressSanitizer for the Linux kernel [19], could be implemented in future work.

this may require instrumenting some base code as well: namely for each kernel heap (de-)allocation from the base kernel, to update associated metadata.


Mapping Kernel Objects to Enable Systematic Integrity Checking Martim Carbone Georgia Institute of Technology Atlanta, GA, USA mcarbone@cc.gatech.edu Wenke Lee Georgia Institute of Technology Atlanta, GA, USA wenke@cc.gatech.edu  Weidong Cui Microsoft Research Redmond, WA, USA wdcui@microsoft.com Marcus Peinado Microsoft Research Redmond, WA, USA marcuspe@microsoft.com Long Lu Georgia Institute of Technology Atlanta, GA, USA long@cc.gatech.edu Xuxian Jiang North Carolina State University Raleigh, NC, USA   jiang@cs.ncsu.edu ABSTRACT Dynamic kernel data have become an attractive target for kernelmode malware.

previous solutions for checking kernel integrity eitherlimit themselves to code and staticdata or can only inspect a fraction of dynamic data, resulting in limited protection.


Regarding workplace privacy, Hendrickx examined the use of social media in a Belgian employment context [15].

to the best of our knowledge, there is no academic legal research undertaken on the specific subject of this paper.


This may however, also result in a reduction of memorability.

if the user is familiar with the song clips presented, by perhaps listening to them regularly, memorability might be enhanced, therefore this is an area we must leave open to further research and debate.


Moreover, KVM can be less dependent than Xen, because it is essentially a kernel module [18], while Xen needs to modify the OS kernel [5].

the VMI library that we utilized requires a patch to KVM [23], and hence it will make the VMM possibly unreliable.


Like Proxos, Overshadow [4] also uses a hypervisor to protect applications from a compromised OS.

unlike Proxos, which places the protected application in a separate VM, Overshadow takes an approach much more similar to the processor-based systems mentioned earlier.


This reduces wasted bandwidth when proxying slow senders, and it reduces latency when proxying fast senders.

adapting CS-BuFLO s transmission rate to match the sender s reveals information about the sender, and therefore may harm security.


Moreover, Kaluza often (about 70% of the time) returns a non-de.nitive answer, either by crashing or timing out.

s3 returns a de.nitive answer much more often.


It is a threshold extension of the Shacham-Waters (SW) signature [26].

we have to note that the extension is not trivial.


Well-known re e.Welle sults by Chandra and Merlin imply that, unless, there is no polynomial-time algorithm that, given a structure as input, returns the core of that structure as output.

in the context of data exchange, we identify natural and fairly broad conditions under which there are polynomial-time algorithms for computing the core of a universal solution.


In this format, Seq is a sequence number for the token, which is encrypted by a shared key K submitted by the GNRS mapping owner.

this key shared by the mapping owner and all the relevant GNRS servers should be chosen carefully to avoid key manipulation attacks while keeping overhead minimal.


The small code base and the absence of many common exploit vectors make MiniOS a suitable basis for building a trusted service on Xen.

the lack of functionality poses some problems, which we will address in this section.


On the other hand, the number of false negatives could appear high.

as we discussed previously, being able to observe a higher number of connections would allow SpiderWeb to use a higher value for tc, and lower both false positives and false negatives.


RSA) by analyzing the data access patterns as done in [32].

implementations can avoid this  Figure 1: Experimental Results threat by carefully handling the data structures.


We re .nding that this is not the case [21], and is often counterproductive [16, 42].

our proposed solution not only provides means to measure how likely someone is who they claim to be, but does so with less burden than existing means.


When M is closest to B (i.e., dM B = 1), the RSS observed at B is PM.B = -26.37 dBm.

for example, if the antenna gain of A to Figure 6: Depicted is the geographical placement of system component in our simulation.


When the user connects to the phishing site, the phishing site can relay requests to the legitimate service provider and replies back to the user as before.

when the service provider sets up a secure connection, it will use the user s certi.cate to setup the session.


In intrusion detection .eld, KDD Cup 99 dataset[3] has been used for a long time as evaluation data of NIDSs.

there is a fatal problem in that the KDD Cup 99 dataset cannot re.ect current network situations and the latest attack trends.


Approaches based on Role Based Access Control (RBAC) [20] overcome some problems with dynamic change of rights thanks to the session notion [14].

the "session" concept also prevents a dynamic reassignment of roles since roles cannot be changed within a single session.


Despite a litany of proposed password replacements over the past decades, no system has proven superior to text passwords when evaluated according to a broad set of criteria [7, 20].

the fact remains that users tend to choose predictable passwords [6,15] and reuse the same passwords across multiple accounts [17].


The password is not sent to the SP as a response.

the data that the user signs with his/her private key contains the password.


The openness of provisioning will allow small-scale service providers to build their authentication and authorization mechanisms around ObCs for securing their services independently of device manufacturers or other stakeholders.

the ObC architecture, solves only the .rst pieces of this puzzle.


Propertyspeci.c customization greatly simpli.es the model, and makes it possible to prove complex properties that could not be proved otherwise.

in MCC, the code producer generating the model is unaware of consumer security policies.


Among them, Google Bouncer6 is a malware detector running on the Google Play store.

it has been recently shown how it can be easily circumvented [31].


This work continues exploring anonymity systems by examining anewcommercial systemusingpreviously explored systems as abaseline.

unlikeprior work, wedo not have the advantage of knowing the technical details of the infrastructureusedbythecommercial systemand thusmust infer its architecture based on user-observable traits.


Since the behavior at the API interface is mostly well-de.ned, it is hard to conceal activities like network access or .lesystem modi.cations at this level.

extracting API call sequences from binaries is far from trivial.


The obvious choices for such a set are administrative domains and encapsulated ranges (giving rise to RHA-style and ARBAC97-style models respectively).

these are not the only choices and we may also consider the administration of disconnected hierarchies (such as those de.ned in ERBAC96 [14] and TRBAC [3]).


Clearly, the higher the con.dence threshold, the higher the classi.cation accuracy becomes.

higher con. 7Note that for decision tree, con.dence score is measured by aggregating entropy reduction at each node; for SVM, con.dence  patterns.


When enforcing perfect privacy, the database does not need to keep track of all queries ever answered in order to guarantee that future query answers cannot be combined with old query answers to disclose information [13].

these nice properties of perfect privacy do not come for free.


On the contrary, wireless cellular networks, using the 3G standards, offer a much wider area of coverage that enables ubiquitous connectivity.

3G cellular networks require signi.cant capital investments and support limited peak rates that range from 64 Kbps to nearly 2Mbps.


This subset of data was a mixture of traffic flows that contained at least one of each type of the various attacks contained in the dataset.

about 92% of the data subset was traffic flows that were considered to be normal.


The complexity of the proof is loga- rithmic in the number of candidates whereas the complexity of ours is linear.

[11] uses complex zero- knowledge proofs of multiplication, and that can potentially make the complexities of the two schemes comparable for a small number of candidates.


However, our experimental results clearly identify the security hole of tablet PCs based on such EM emissions.

there are several products naturally resistant to the EM display stealing.


On one hand, in case the network appeared to be trustworthy, the number of the agents can be reduced.

in case the hosts in network appeared to be distrusted and/or malicious then the number of the agents can be increased to provide the required certainty factor.


Besmer et al [4] introduced a new application-to-user policy that restricts application s access to user information while still allowing desirable functionality, which is most similar to ours.

in addition to the policy model, we also provide a framework that separates application components for .ner-tuned information .ow controls.


The right 32-bit half is set to a .xed value.

the IV is not directly stored in plain; rather, the single bits of the IV are distributed over several bytes of the header.


Speci.cally, the presence of centralized marketplaces or app stores may greatly streamline the process of mobile app browsing, downloads and installation and thus boost smartphone popularity.

the very same centralized marketplace model could also signi.cantly contribute to speedy mobile malware infection possibly within a short time period.


Moreover, modern videosurveillance systems are beginning to feature functionalities for automated image analysis which make easier the task of the human operators whilst increasing security.

this increased e.ciency in detecting events and collecting information is raising even more privacy concerns.


5.1 Performance The goals of security and performance often appear incompatible.

our approach has one appealing aspect: The transitions between VMs and hypervisor via VM exists and VM entries on current generation hardware, still in.ict a signi.cant overhead.


However, the cost of this approach would be a much larger TCB that incorporates device-speci.c drivers.

the current TLR design is generic it works with all TrustZone-equipped devices.


As an alternative, probabilistic veri.cation schemes [16] can be applied such that every router decreases the veri.cation probability if the DATAHASH veri.cation succeeds.

if a router detects a packet with a bogus hash value, the probability to run hash veri.cation increases.


In fact, anonymous credentials have formed the basis for privacy-preserving digital identity management frameworks [16].

such frameworks have very broad goals and focus on demonstrating users attributes (e.g., age) to online services.


A user with an UNCLASSIFIED clearance can access both NAME and TEL, and naturally DEPT is prohibited.

if we consider that TEL depends on DEPT (e.g.


Some have proposed market-based approaches, such as a system in which a privacy-protecting Internet service provider (ISP) may charge more than an ISP that does not provide privacy.

as Shapiro [3] argues, such market-based approaches make it possible to sell away one s civil liberties, and also create a situation where the wealthy are more likely to retain their liberties than the poor.


The bootloader is installed into the program .ash before node deployment, through a conventional hardware programmer.

what the bootloader does (a) C code to be exploited in sensor application and the (b) Packet payload to inject the malicious code.


Our system can express security policies that control covert and overt storage channels.

certain classes of information- flow policies are not controlled by our system: timing and termina- tion channels, which would be more important in a malicious-code setting.


Trishul and the VM based .ow control system described in [12] take a step towards this approach and allow to process security policies tagged to data.

the authors do not describe how these policies are speci.ed and administrated in a secure way.


In fact, our lower bounds hold against algorithms that can use unbounded storage and perform arbitrary computations per update.

the pan-private algorithms for distinct count and heavy hitters we present here are actually streaming algorithms that use only polylogarithmic time per update and polylogarithmic space.


To match regular expressions, Sommer and Paxson [36] used a DFA.

unlike our work, they performed matching on already-normalized tra.c.


In storage, systems like SUNDR [17] and Sirius [11] have examined securing block and .le-level storage on untrusted substrates, and similar work exists for databases [20].

this approach is rarely encountered in the OS literature, with the exception of architecture-level research such as XOM [18, 19] and SP [6, 16].


Interpreting inequality constraints as equality constraints introduces inaccuracies that prevents the types of some programs to be inferred properly.

since constraints are only generated in case they cannot be shown to be satis.ed at the point of introduction it is always possible to resolve any such inaccuracies by providing type information in the form of type annotations.


7.3 Power Consumption Analysis The Vigilare system might increase the total power consumption of the entire system, due to additional hardware.

the opposite is often true as well because replacing the functionalities of software with a hardware module decreases overall power consumption as it improves e.ciency.


Access To Sensitive Application: This setup allows patients to pass their time playing games, listening to music and chatting with friends and family using the Android tablet.

nurses can make use of the same tablet by retrieving or updating the patient s information.


Fortunately, many of the attacks can be thwarted with known countermeasures obtained from best practices in network security, software validation, and operating system security to ensure the attack cannot occur.

one must be aware that attack vectors can be activated simultaneously by the attackers.


In the case of a dynamic access the temporal authorization supports relaxation in terms of serviceability and single-sign-on (SSO) and on the other hand restriction to the maximum time where an access to the requested data is legal in terms of the legal situation.

the time alone does not reveal whether the access is legal and is therefore used as one of several context facets in our approach.


SELECT MIN(timestamp), MAX(timestamp) FROM MessageLog [ROWS 100] WHERE outcome = "success" AND serviceId = "5" If this query is executed by the query processor at Level [1, B], no rewriting is needed.

if the query is executed at Level [T, T ], the query must be rewritten to ensure that it can view only authorized information.


AngeL uses, on the contrary, low level attack signatures for efficiency and simplicity reasons.

abstre~ting away from specific details allows to identify variations of attacks that may oth- erwise go unnoticed, thus reducing the impact of updating the signature base of the system.


Based upon known attacks it does not appear that any information about the encoding of D can be obtained from S, thus I(D; S) = 0.

we cannot say that ¬expl(S) because it is unclear whether the unencoded instructions alone are su.cient for successful attacks.


rx2 receives zero interference from m1 because the precoded c1m1 is in the null space of h2.

m1 is decodable at rx1 because c1m1 is not orthogonal to h1 2.2 Physical-Layer Security in MU-MIMO As shown in Eq.


Web-based data-intensive applications are the majority of those applications.

data Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for pro.t or commercial advantage and that copies bear this notice and the full citation on the .rst page.


But in case of smart assisted home environments, no skilled administrator is present and most of the users are less than fully knowledgeable.

once all appliances in a household are automated and connected through a network, it becomes essential to consider issues of security, especially access control.


While the former approach does not require any speci.c permission, the latter approach requires a permission to access the microphone.

we consider the detection of PIN inputs on a sequence of sensor values as solved and beyond the scope of this work.


Algorithms with frequent memory references like AES, Blow.sh and SEAL bene.t from multithread when ME number is small (one or two), because their memory access latency could be suf.ciently hidden.

throughput stops growing linearly for all algorithms from 4 threads to 8 threads, as ME s computing power has already saturated under the 4-thread con.guration.


PRIVACY PRESERVING POLYNOMIAL EVALUATION The algorithm presented in Section 4 allows users to control the search capability on their data items by de.ning a set of access keys for each data item, and storing all data items controlled search polynomials in servers.

to protect these polynomials from untrusted servers, privacy preserving polynomial evaluation is needed to allow servers to evaluate f(a) without the knowledge of the polynomial f(x) and the element a.


However, we note an important difference: while in [35] the challenge (I , {(i, .i)}i.I ) is randomly sampled, challenges in Fortress are generated pseudo-randomly using the pseudo-random bit generator g with a seed extracted with GetRandomness.

we argue that this does not bear any practical implication.


Typically, the larger the character set, the higher resistance to random guessing attacks each challenge can have.

a larger character set can also imply a higher number of characters that look similar after distortion, causing confusion.


If neither x nor y contains { n }, we must subtract the a set { n } from the .nal decision set because { n } is the a a weakest decision.


If so, the worm generates a random list of IP addresses and probes each machine on the list ia an attempt to infect as many computers as pos- sible.

this first version of the worm uses a static seed in its random number generator and thus generates identical lists of IP addresses on each infected machine.


Aside from the fact that the central directory is not MACed, our two main concerns with PKWARE s solution are that (1) we believe that protecting against information leakage from an encrypted .le s header should not be an option and (2) archives created with the above option turned on are no longer parsable under the traditional Zip speci.cation [9].

our proposed .xes involve modifying the main .le and central directory records such that privacy-critical metadata information is always hidden and the resulting Zip archives are still parsable under the traditional Zip speci.cation [9].


As to security, we only de.ne adaptive security against chosen plaintext attacks.

our de.nition can readily be extended to capture chosen ciphertext attacks.


There does not seem to be anything special about these pairs that leads us to believe they are unique.

in other cases we .nd the dissemination-centric system unable to fully match the g-SIS system, e.g.


A Bayesian network transformed from the NBN as shown in Figure 1.

3.3 Bayesian Network Model in some situations, dependencies among some information variables may signi.cantly affect inference results.


No information about the mail leaks to the resource server, so this plug-in respects the information .ow policy.

plugin2 will only download the external resource if a certain property holds for the user e-mail, thus violating the policy: the owner of the resource server can deduce that the user sent a mail satisfying the isInteresting property.


The success of the Internet has created a dependency on communication as many of the processes underpinning the foundations of modern society would grind to a halt should communication become unavailable.

much to our dismay, the current state of safety and availability of the Internet is not commensurate with its importance.


Many policies consider a passphrase as a long sequence of characters or words[8, 2, 3, 6] and estimate security metrics such as size of search space and guessing e.ort accordingly[6, 14].

when users choose sentence-like or phrase-like passphrases, due to grammatical structures the search space and guessing e.ort will decrease.


Thus, they provide a natural way to control access for collaborative activities in teams and workflows.

we argue that TBAC modes are specific configurations of role-based access control, where context information can be viewed as constraints.


4.3.2 Performance Evaluation involved in more than one case.

it is easy to see that the secret value corresponding to each class is consistent with the others.


Microsoft s browser, Internet Explorer, is susceptible to the attacks.

it seems to only support embedding of PDF documents using the embed tag.


Finally, [15] presents various security mechanisms and access control policies and discusses the applicability of these mechanisms and policies to multimedia data.

these models tend to support single files and address the needs of generic multimedia content.


Just as with memory, we would have to translate the existing Hotmail code into .NET and run it.

it has often been observed that JavaScript execution is not the dominant part of client-side application execution, in terms of the fraction of time it takes.


With this policy, every recipient must maintain a table of the last value from every sender it receives.

for RAM-constrained sensor nodes, this defense becomes problematic for even modestly sized networks.


It re.ects the strength of the authentication and how easy it is for an attacker to fool the authentication process: The stronger the authentication, the higher the con.dence that a user corresponds with the claimed set of attributes.

the strength of an authentication method depends on many criteria and these criteria di.er tremendously between di.erent categories of user authentication.


In general, like other types of textual documents, textual requirements written in English are typically unstructured, ambiguous, and include implicit information, posing challenges for NLP.

in textual requirements, ACP sentences (i.e., textual requirements sentences for describing ACP rules) tend to follow speci.c styles such as: [subject] [can/cannot/is allowed to] [action] [resource] for role-based ACPs.


The Strata Guard system used during participatory observation provided several features in this direction, such as automatic discovery of the network s devices and a quick tuning option.

its GUI did not allow the con.guration of all the options required to optimize IDS usage (e.g., memory partitions).


N (R5) pC 4 p C |=UC 4 Dele gaet (Pr iv, C) From analysis of messages 9 and 13, we find that goals G1 and G2 are satisfied.

we still need to establish that the secure redirection property assumed by the belief logic holds for the protocol.


PROTOTYPE IMPLEMENTATION We modi.ed OpenSSH5.9p1 to implement Algorithm 1.

the optional junk recovery algorithm described in Algorithm 3 was not implemented.


We note that there have been instances where attackers have compromised both the computer and PSD at the same time, e.g., the Zeus banking trojan[6].

compromising the user s computer and having physical access are not equivalent.


Business Process-based Valuation of IT-Security Thomas Neubauer, Markus Klemen, Stefan Biffl Institute of Software Technology and Interactive Systems Vienna University of Technology, Karlsplatz 13, A-1040, Austria {neubauer, klemen, biffl}@ifs.tuwien.ac.at Abstract Growing business integration raises the need for secure business processes as security problems can affect the profit and the reputation of a company.

decisions regarding a reasonable level of security in a business environment are often made in a valueneutral way.


Hence, the dishonest entity Ai can engage in an information .ow with Aj and subsequently leak the information, thereby achieving a short term utility gain.

soon Rt, as computed by Aj, would drop; if Ai continues to report rt = 1, then its long run utility from Aj would be zero.


If we assume a worst-case scenario where the adversary has compromised at least CERT_TH of A s trusted CAs, A s policy private key, and one or more of A s trusted logs, then the adversary could forge an MSC, and the necessary log proofs or registration receipts.

even in this case the MSC would have to comply with A s SCP, constraining the malicious MSC.


In particular, we observed that when the mouse/keyboard information is sent to the server because of a visual change, the server responds with a relatively large amount of information (for example a new image).

we hypothesized that in covert tracking, the server would not respond with any substantial amount of data (if any at all).


Thus, compared to microbenchmarks that are exclusively exercising operating system functions, applications in Xen do not run proportionally faster than applications in UML.

as illustrated in Figure 5, Xen still has the fastest invocation mechanism.


managing Access Control Complexity Using Metrics Trent Jaeger IBM T. J. Watson Research Center 30 Saw Mill River Road Hawthorne, NY 10532, USA Email: jaegert@watson.ibm.com ABSTRACT Generalaccesscontrolmodelsenablefexibleexpressionof accesscontrolpolicies,buttheymaketheverifcationof whetheraparticularaccesscontrolconfgurationissafe(i.e., preventstheleakageofapermissiontoanunauthorizedsubject)difcult.Thecurrentapproachtoexpressingsafety policyinsuchmodelsistouseconstraints.Whentheconstraintsareverifed,thentheconfgurationisverifedtobe safe.theadditionofconstraintstoanaccesscontrolconfgurationsignifcantlyincreasesitscomplexity,so itquicklybecomesdifculttounderstandtheaccesscontrolpolicyexpressedintheconfgurationsuchthatfuture changescanbemadecorrectly.Weproposeanapproach wherebythecomplexityofeachaccesscontrolconfguration isestimated,sotheadministratorscanseetheefectofa confgurationchangeonthefutureabilitytomaintainthe confguration.Weidentifymetricsformakingcomplexity estimatesandevaluatethesemetricsonsomeconstraintexamples.Ourgoalistoenabletheuseoffexibleaccesscontrolmodelsforsafety-criticalsystemsbypermittinglimited useofconstraintsthatdonotcomplicatetheconfguration beyondamaintainablecomplexity.


that the host may be compromised and invisibly update malicious software or break its assurances.

this can be done easily on clients as well (for example, via a rootkit), so we should assume at least a parity in security between host and clients.


The bene.t of exposing the OS system calls as uPro API functions is that it helps the migration of existing applications.

the system-call interface is not portable across OSes and prior research has documented various kinds of pitfalls when security relies on the system-call interface [20].


In this .gure, it can be seen that when a biases the system towards behavior, the overall outlier rate is low, whereas the distance between the old RBAC con.guration and the resulting RBAC con.guration is large.

when a is biased towards the distance to old RBAC con.guration, the overall outlier rate is high, while the distance between the two RBAC con.gurations is signi.cantly smaller.


Such a clean-slate approach is attractive because it can potentially offer security and robustness guarantees beyond those of Min-V.

such a porting effort needs to overcome two challenges.


For example, accesses to addresses other than the memory area of the shellcode itself are ignored.

shellcode is meant to be injected into a running process and it usually accesses certain parts of the process address space, e.g., for retrieving and calling API functions.


Our experiments followed the same logic we used for the optical attack.

in the microscope case, we assume that the attackers have already seized the smartphone and are able to investigate the screen in a laboratory as long as desired.


3.2 Generalized Signature The key challenge to a successful buffer over.ow attack is how to overwrite the target control-sensitive data structure in the victim application.

the distance between the over.owable buffer (UserID[] in the above example) and the target control-sensitive data structure (the return address of Input()) may vary for different instances of the same network application for the following reasons: .Due to memory alignment requirement, different compilers may allocate local and global variables in an order that is completely different from the order they appear in the source code.


Multi-touch Graphical Passwords The design space of graphical password systems has been extensively explored for mobile and single touch interaction.

multi-touch interaction allows us to explore both parallel and sequential actions, thereby allowing us to design schemes that both obfuscate and explicitly hide PIN entry.


The median result is 25.73%, the 90th percentile of the overhead is 68.37%.

the signi.cance of these results is limited as we are unable to control for network-induced delay.


Unlike Code-RedI, CodeRedlI neither defaces web pages on infected machines nor launches a Denial-of-Service at- tack.

the backdoor installed on the machine al- lows any code to be executed, so the machines could be used as "zombies" for future attacks (Denial-of-Service or otherwise).


For example, when loading tainted data, the taint tag in the target register should be set accordingly.

such instructions are absent in the typical ISA supporting DEP.


Participatory Sensing (PS) has the potential to o.er a new understanding of our environment and lead to innovative applications that create added value for the contributing users.

for this to materialize, users must embrace the initiatives from the people, for the people systems and participate in great numbers.


There is no analogue of our access state in the STATL system, so there is no consideration of its interaction with high-level properties.

it supports the significance of our work that speci.cation at a high-level of undesirable behaviors has been so effective in this application.


For node Y that receives a packet with source field set to A in a time slot that is not allocated to A, is an anomaly and so Y will detect the Masquerade attack.

if adversaries follow the TDMA protocol and send their packets in the time slot that is allocated to the node whose identity they use, masquerade attacks cannot be detected.


If a systemis able to exactlyimplement theintendedpolicy and the intended policy is fully known at the outset, then there are no miscon.gurations to detect.

regardless of the expressiveness of the policy language used by the system, neither of these conditions is likely to be met: the intended policy is often dynamic, i.e., developed in response to new situations; and even when the intended policy is not dynamic, it is rarely fully speci.ed at the outset.


To illustrate, we varied the amount of memory allocated to the userOS andfound that average suspend durationsfor2GBand4GB memory are11.86 and16.64 seconds respectively(std.deviation0.4 and 0.85 respectively).

we note that if the uApp has lower memory requirements than the user OS, the suspend-to-disk code in the user OS could be modi.ed to only write the amount of memory needed by the uApp to disk.


Construction frameworks such as the Spring framework [5] provide support for separating page navigation from business logic.

the enforcement of control .ow should still be done inside server-side scripts using validation methods.


The SCA tells the hijacker how to direct the vulnerable software to jump to any speci.ed address.

the hijacker is not toldhow to place exploitcodeataknown address inside the process s address space.


One may think that system call table manipulation attack can be easily mitigated by making the system call table immutable after the system s boot process, and this immutable memory region can be simply protected by hardware-based external monitors.

we implemented the rootkit with ATRA that successfully manipulates the system call table without involving any changes in protected memory regions and subverts the naive defense mechanism.


violates noninterference, if xis an untrusted value and the contents of .are trusted.


We assume that the corporate's CSO and the administrators have decent control over the applications used within the corporate's boundaries, and will not allow the installation of unauthorized applications.

if we consider typical private computers outside the corporate's boundaries we should notice that many third party applications can read both Microsoft Office documents and Adobe PDF files.


4.2.2 Retrieving minutia templates from AliceFDrive Theparameters ofbAPI4 HMFVVerify imply thatAliceFDrive s reference templates exist in the clear in memory and we have con.rmed this by running AliceFDrive s authentication program within IDA Pro.

reading memory of a computer programusually requires some expertise and may beadaunting task for ordinary users.


As such, the Set(x) functionis optional.

theCC stillpollsthePUF to generate the pair of keys.


Similarly, a user can be a member of many teams, and a team may have many users.

there are constraints when assigning user to teams.


According to rule (ii), both A-1 and B-1 can now be removed leaving C-0, A-2 and B-2, and the system should be recoverable up to a snapshot after the creation of B-2.

if the two clients replicated the block-version A-2 now fail, the clients will be unable to recover back to a consistent snapshot because the replicas of both A-1 and B-1 have been garbage collected and all replicas of A-2 have been lost, violating the guarantee that the system can recover with up to n - 1 failures.


Additionally, the position of JitterBug, between the machine and the human, further complicates detection because of the variation in human behavior, i.e., di.erent typing characteristics.

as JitterBug is a covert timing channel and transmits information, there is some a.ect on the entropy of the original process.


[27] propose a memory attestation solution (BIND) to attest routes using trusted computing.

this solution is quite time-and memory-consuming and may exacerbate BGP convergence performance, e.g., there are several communication rounds for encrypting/decrypting message authentication codes and attesting a received route update in a BGP speaker.


In this scenario, the similarity computed for the Permit rules represents, for both rules combination algorithms, the sets of requests authorized by the two policies.

while in case of Deny Override such set of authorized requests has to be pruned from the requests which satisfy at least one Deny rule, no pruning is needed in case of Permit Override .


Since SNRi is not a concave function, w.r.t wi [3], the optimization problem (14) is not convex.

with a predetermined value of t, the SNR constraint can be transformed into a second-order conic constraint [3], which is convex.


This makes it hard, if not impossible, for an adversary to launch the attack even with unintended instructions.

xFI mainly su.ers from practical de.ciencies: The binary instrumentation framework Vulcan [23] used by XFI is not publicly available and is restricted to Windows.


The topic of executing a targeted attack is only brie.y touched on, as it is mentioned that a means will be necessary for an adversary to specify the payload goal.

no means is given for actually specifying the goal, or for achieving it.


A naive solution to the disclosure control problem is to design ontological fragments that satisfy every permissible access -and thereby incorporate disclosure control requirements in the design of the ontology itself.

this is counter productive, as it interferes with extendibility and produces multiple versions of the original ontology, thereby giving rise to known dif.culties of version control and meta-data replication.


While it takes about 2 seconds in the example of small applications such as ghttpd, it may take up to 20 minutes for some likely invariants in the case of snort.

it took BLAST far less than that to disprove more than 90% of the invariants.


We can extend Theorem 5 to accommodate multiple con.gurations that violate condition (1), because Theorem 4 can accommodate this scenario.

if the goal is to maximize the time that the system can stay in the con.gurations that violate condition (1), the optimal solution is with respect to con.guration Cj,where j is given by Eq.


We selected word lists of particular sizes so that different conditions would each have 30 bits of entropy.

we later discovered that word lists not restricted to a particular part of speech contained duplicate words.


It briefly comments on the weaknesses of about a dozen simple CAPTCHAs, which were claimed to be broken with a success ranging from 49% to 100%.

no technical detail of the attacks was publicly available.


This mean that all requests authorized by John will be authorized by Bill whereas the opposite is not true.

the similarity between the policies speci.ed by Bill and Jane (both using Deny Override ) is Shu.e because the similarity for the Permit rules is Converge whereas the similarity for the Deny rules is Shu.e .


Some of these vulnerabilities are highlighted in the SCA specification and guidelines have been provided to counter them.

these guidelines may not always be followed in SCA non-compliant implementations.


It is easy to see that there exists no allocation for T , H2, f, and UT .Only Claire is authorized to execute t1 and t4 with respect to UT .

the SoD constraint s2 in f does not authorize Claire to execute t1 and t4 because according to H2 she has already executed t5.


The RBAC in SELinux is a user-centered concept for grouping sets of domains, introducing a new abstraction layer to the TE, and it is used also for limiting permissible security context transitions.

the important part of the access control is in the TE.


There is also no evidence that QUALCOMM employees engaged in any email correspondence or other means for working with the JVT to develop the standard [7].

all of these claims, and the other denials of involvement, would be proven false after a second round of discovery During trial, counsel for Qualcomm stated to the judge at sidebar that no emails existed between Qualcomm employees and the JVT.


This proved impractical, so we used an highly e.cient implementation of the Lanczos algorithm, with bidiagonalization and partial reorthogonalization, which o.ers a complexity of O(p · q · r2), where r is Figure 3: Comparison between the classi.cation of normal tra.c (above) and Nessus tra.c (below) over 50 classes by a principal direction algorithm the rank of the matrix and so r = min{p, q} [18].

even this algorithm shows di.culties when the cardinality of the training set grows.


The analysis of differences between our subjects from the US and the ones reported by Smith s study [29] did not reveal a statistically signi.cant dif ference in gender distribution.

there was a statistically signi.cant difference in age, income, and education.


Modulation can compensate for the larger distance by encoding complex informationasasequenceof simpler signals renderedbydisplaysas simple as a single LED [26].

the sensor that decodes the signals is typically af.xed to the user s device and therefore the entire device would have to point towards the signal source.


The main advantage of librarybased instrumentation is reduced overhead: only library code (as opposed to application code) needs to be instrumented.

library-based approaches do not deal well with information propagated through non-library code and data structures such as char[], byte[], and custom characterlevel sanitizers.


Second, process checkpointing (e.g., Flashback [20]) has been researched for many years.

rolling back the attacked process to the latest pre-attack checkpoint could result in the inconsistency among interactive processes, and the secondary infection effects caused by the attack is not repaired.


In general, solving games against an adversary is a di.cult problem and can be computationally intractable.

the framework of robust statistics addresses the problem of outliers in data.


This increases the load on the LBS and on CacheCloak.

the mobile user is only retrieving data as it is needed, and will not see this overhead.


Some limitations of the schemes of [30] are lifted in [6].

a sequential-aggregate based MS scheme will require a number of communication rounds proportional to the number n of signers involved in a signature, as well as napplications of the trapdoor function to verify, while all previous protocols, including ours, are constant-round and have constant veri.cation cost.


4.1 Discussion We have shown that the infection tree has both a high patient zero occurrence frequency and a long walk length.

as the volume of normal tra.c increases, it adds more noise to the selection algorithm.


RFID guardian [30] provides protection by actively jamming suspicious NFC transactions.

active jamming consumes considerable power and requires bulky hardware (e.g., RF ampli.er and large battery), which signi.cantly limits RFID guardian s applications.


The last .ve categories are related because they re.ect the situation where host-based features of a malicious URL appear to be non-malicious.

the remedies for mitigating these kinds of false negatives differ.


Using analytical modeling and highly detailed simulation of the GSM air interface, we show that the simple model described in the original study underestimated the traf.c volumes necessary to to effect a high-impact attack by approximately a factor of three.

while the speci.c estimates made by Enck et al.


In regards to the cases detailed above, we can see how gray hat hacking can also shape the policy and response of different companies.

the cost for these companies is the collateral damage that is incurred for having to learn of these security flaws the hard way.


In terms of the number of passwords that was completely resistant to shoulder surfing, Line Snaking managed to have about 12% out of the total passwords completely un-captured compared to Disappearing Stroke with just 4%.

we did not find this difference to be statistically significant (U= 102, z=-1.71, p=0.087, r=-.29).


Another concern is that an OTA update might disable FireDroid.

to disable FireDroid there are two main approaches: either modifying the init.rc .le or disabling the ptrace() system call.


SSO avoids the inconvenience of typing passwords many times throughout the day and potentially reduces the risk of typing a password by mistake on an attacker's phishing web site.

sSO requires users to maintain control over their web browsers, so someone else doesn't use their cookies to access web sites using their identity.


The e.ectiveness of keystroke dynamics as an authentication characteristic for traditional computer keyboards has been deeply investigated [10], [11], [12].

a comparable e.ort has not been devoted yet to applications dealing with keypads used in mobile handsets or in ATMs.


Existing approaches have used role mining [5], the application of data mining techniques on permission to user assignments to extract roles and hierarchies.

role mining su.ers from the inherent problems of their chosen mining technique, causing conceptual errors in the way roles are automatically extracted.


To the best of our knowledge, the work more closer to our proposition is described in [15], where the authors present a semantic access control aproach based on a context-aware policy model, which treats context as a .rst-class principle for policy speci.cation and adopts a hybrid approach to policy de.nition based on DL ontologies and LP rules.

as occurs with the existing approaches from the secondgroup,thisapproachpresent a limitedsupporttothe context dimensions (e.g.


Similarly, system administrators can be relabeled to be ordinary users.


By executing a malware sample multiple times, we are therefore able to gradually and automatically move from partial containment (in case in which part of the generated interacton is still unknown) to full containment, where all the malware network behavior is fully modeled and emulated by the system.

it should be noted that the full learning of the network behavior of the malware is di.erent from the full knowledge of the protocol.


For computer networks, they have proven to even throw back the most powerful attackers [12].

similar to WSNs, they leverage properties that do not exist in HASs, such as routing and looser energy constraints.


Security is claimed to be an important component in this framework.

the formal speci.cation has not been released yet [7].


In this scenario, 2.5% of the passwords could be cracked in less than a day, and 4.6% in less than a week.

if two edits are applied rather than one, the strengthening algorithm is still largely e.ective, with only 1.3% of the strengthened passwords recoverable in a week.


When comparing the RBAC models in Figure 4(a) and (b), it is noticeable that there are di.erences between them.

it is hard to clearly detect the structural di.erences just by looking at both .gures.


For appliances with sensors to monitor device status, it is also challenging to quantify (usually non-linear) sensor inputs and assess risks.

it requires intensive human and behavior studies to observe usage habits of di.erent devices and construct usability functions from the observed patterns.


Their idea is to reduce the attack surface by eliminating potential triggers for a backdoor.

an attacker could still add a backdoor by adding additional command handlers or installing mechanisms that entirely bypass the authentication process in a server application on certain triggers.


The .le system is deniable if the adversary only sees the .nal content of the disk.

it cannot defend against an adversary who possesses multiple snapshots of the encrypted partition.


Thus, the goodness values of n-grams eventually dictate the classi.cation criteria of our scheme.

the value of smoothing factor a determines the e.ect of goodness values of last ngrams in calculating the overall impression of the process.


CONSISTENCY AND SECURITY ISSUES The replication of the shared document and the policy object is twofold bene.cial: .rstly it ensures the availability of the shared document, and secondly it allows for .exibility in access rights checking.

this replication may create violation of access rights which may lead to divergent document copies.


Instead it is self-interest (and all its attendant vices) that dominates behavioral norms.

through skillful and e.cacious management of the individual s sel.sh desires, public bene.t may emerge.


Brakerski and Vaikuntanathan [7] subsequently constructed an FHE scheme1 based on the worst-case hardness of approximating lattice problems such as GapSVP (a promise version of the shortest vector problem on lattices) which have been studied extensively and are by now considered standard cryptographic assumptions.

they required that the problem is hard to approximate to within a subexponential factor (in the dimension of the underlying lattice).


This has been shown to be e.ective as mentioned in [11].

the main challenge is how the fee structure can be managed, since it requires co-operations between the many trusted hosts in the P2Pcloud-II and P2Pcloud-III models.


In user directed delegation, any user's system may mediate delegation to resources under the user's control.

in both situations it is necessary to enforce predefined delegation policies to prevent power abuses by individual users.


EHMA is proved to significantly reduce the number of the external memory accesses and improve the performance of the matching process.

it may not work well when the number of the patterns increases.


biometrics include low cost (no requirement for specialised hardware) and transparency of use [10].

being a form of behavioral biometrics, keystroke biometrics has lower accuracy when compared to physical biometrics due to the inherent variation in human behavior.


In its active period, bot tweets more frequently than human.

bots tend to take long-term hibernation.


Alternatively we could connect the PAWS router directly to the sharer s internet connection and then connect the sharer s router to the PAWS router, this would have the advantage that we can accurately measure the sharer s network usage and therefore infer the unused capacity that could be made available to the PAWS network.

this would not work for many reasons: The PAWS router would have to work as a modem therefore would have to be con.gured and suitable for all ISPs and connection methods (.ber, ADSL, etc.).


Conceptually, the more information that we store about a pair of documents, the easier it should be to make a decision as to whether they are co-derivatives.

the processing required evaluating the query, and the space required to store the index, increase proportionally with the fingerprint resolution.


Since we separated arguments from jump addresses, the two push instructions will only overwrite arguments and not jump addresses.

one can backup the affected arguments through a store gadget before invoking the system call.


For the systems with n = 10 states the maximal relative error reaches almost 20% of computed bounds, while for larger system (with n = 20 states) the maximal relative error is 2% of computed bounds.

it is worth noting here that conservativeness of the presented results is (at least partially) caused by the fact that for each system we only considered random initial points, and random uncorrelated attack vectors and noise pro.les/modeling errors.


If the returned search value is an even negative index, then the target address does not belong to any of the modules and is treated as a violation of CFI model.

if the return value is an odd negative index, the target address belongs to the module with base address equal to the address at index -1 in the loaded module array.


In effect, most previous anomaly detection work tried to detect memory tampering by detecting anomalous program paths caused by the memory tampering.

during our experiments, we found that a large percentage of memory tampering incidences do not alter program control flows.


Identifying the set of permissions that would enable kernel compromise involves enumerating the set of permissions that could impact kernel integrity, such as the kernel memory, modules, etc.

we may also want to protect other subjects that are accessible to adversaries that also have these permissions from our targeted subjects.


MOTIVATING EXAMPLE The policy integration method we propose in this paper can be applied to several applications ranging from Web Services to Grid systems.

in the following we motivate our work by presenting a very simple scenario related to the CDN introduced in Section 1.


[31, 18] provide a way of editing and distributing policies.

none of the papers envision how a joint administration of access control could be achieved.


In our concrete construction, all the ciphertexts and the secret keys holds by the users are normal,where by normal we mean that they do not have Gp2 parts.


We also need to mention that the commercial services of new mobile communication standards, HSPDA (High-Speed Packet Downlink Access) and CDMA2000 EV-DO Revision A, will start in Japan during 2006.

3G, the previous generation of cellular phones, has spent nearly 5 years to take the 50 % share of the mobile phone subscriber market (45 million out of 90 million as of January 2006 [13]).


Its run-time immutability and isolation is conditional to what other applications are run as protected applications.

the isolation of the MTM and its data from the OS (and system services) is enforced by hardware access control.


The identity box simpli.es the creation and management of protection domains: a system may create an identity box on the .y without regard to any external user database.

this does not mean that identity boxing requires a system to admit arbitrary users.


An easier captcha can be used when the impact of abuse is low, or when it has been veri.ed by other means that the user is unlikely to be an attacker (e.g., from a trusted IP address).

even in the low risk case, designing a usable captcha is still a challenge.


In this environment, Shunting cannot realize its main performance bene.ts, and the monitoring task likely calls for using custom hardware instead.

in many other environments we expect Shunting to potentially deliver major performance gains.


This allows sensors (or other I/O devices) to map all their interrupts to the secure world and to protect the integrity of those sensors from untrusted code.

this step is not suf.cient  Overview of how the serial port interrupts are handled on the ARM platform.


Fortunately, it is possible to treat phishing mails as spam.

although spam .lters work quite well today, they cannot guarantee that all phishing mails are intercepted.


Similarly, Howell and Kotz [12] based a semantics for SPKI on the logic of authentication [1].

this work is only concerned with the authorization semantics SPKI/SDSI, not certi.cate retrieval.


Using passwords is the most common technique for user authentication in telecommunication systems.

often users choose weak passwords consisting on simple words, short and simple sequences of numbers or easily available information about themselves (i.e.


In addition, EFS also enables .le sharing between a small group of users and provides mechanisms to retrieve lost keys.

eFS is not designed to ensure integrity of data and meta-data.


Furthermore, there is a current shift in vehicle architectures, from isolated control systems to more open automotive architectures that would introduce new services such as remote diagnostics and code updates, and vehicle-to-vehicle communication.

this increasing set of functionalities, network interoperability, and system design complexity may introduce security vulnerabilities that are easily exploitable.


By forcefully mapping the reserved extended area of the physical memory, such malware can even corrupt the Meta-Os or the saved snapshot.

mapping of reserved physical memory area is unusual and can be considered suspicious.


From the above discussion we see that one can expect that in general the complexity of recovering hidden com- ponents can be quite high if they are constructed by tak- ing slices of original modules.

additional issue of controlling the cost of splitting modules in terms of the runtime overhead they introduce must also be addressed.


This is the .rst protocol to allow the capability of revocable credentials in the model with strong non-transferability guaranteed via biometric authentication.

there are admittedly some weaknesses in our protocol, which we would like to address in the future.


The preceding arguments show that brute force attacks are impractical and that search attacks, no matter how clever, will require signi.cantly more time and mental e.ort from victims than is required to log in.

we cannot analytically determine how users will react when presented with a search attack on their password; for that, we need a user study.


(R1) Lifetime (R2) The number of activations (R3) The number of creations of new capabilities (R4) The inheritance of permissions related to role hierarchy (R5) The number of hops of capability transfer There are also other constraints such as the depth of inheritance of permission to create new capabilities.

here we do not consider the constraints on the destination of capability transfer, because it is not plausible from the viewpoint of the implementation.


In their proposed POR scheme, disguised blocks hidden among regular .le blocks are utilized to detect data modi.ed by the server.

the communication cost in this scheme is linear to the number of elements in each erasure coded .le block.


There has been a large body of research propose to introduce diversity in the form of randomization at different abstraction levels (in memory locations, compiler, program execution) [8,26].

the concept of exploiting diversity in HIDS-based anomaly detection systems has not been well explored [22].


This performance indicates that the tools that we use can handle large number of invariants and therefore large models, but the construction time might takes several days for a signi.cant application.

it is useful to remember that this is a one-time cost in the process of securing such application.


Surprisingly, the role E1, which is part of Project 1, becomes outside of the control of PSO1 due to the deletion of PL1, because E1 is not in the administrative scope of either PE1 or QE1.

in ARBAC97 and Oracle, the effects of each operation tend to be simpler and easier to understand.


To protect the access policies, state-of-the-art solutions exist to enforce sensitive policies in outsourced environments [2, 3, 12].

such solutions assume that the outsourced server does not collude with any client.


For example, human resource employees often access employee records.

while traveling to recruiting events, company policy may dictate that laptops must not contain unencrypted copies of employee records.


3.4 Enhanced Access Decision Performance The meta model described in the previous section is convenient for administration, and the access control information can theoretically be used directly by an access decision mechanism (e.g., as described by the ISO standard in section 2.1).

in practical implementations, some additional constraints for the access decision mechanism of an application system exist:  For business critical applications such as core banking applications, the access decision mechanism must demonstrate optimal performance and availability.


Bootstrapping the service: In order to suggest plausible responses to users, RecDroid starts from a set of seed expert users and make recommendation based on their responses.

it is impractical to have our expert users to provide plausible responses to hundreds of thousands of apps available on the market.


RELATED WORK A few network layer solution approaches have been proposed for anonymous unicast routing in MANETs in the past decade such as [12], [18], [17], [7] and [15].

research addressing security issues in multicast routing, mainly focused on sender/receiver authentication and key management algorithms instead of secure routing features like anonymity or location privacy.


Both de.nitions are aimed at unconditional security.

session key distribution in [27] requires that any coalition of at most t valid group members cannot get any information about another member s personal secret, while De.nition 2 in our paper requires that the uncertainty of such a coalition to determine another member s personal secret is at least b bits.


Indeed, the termination behavior of the program in Listing 1 reveals everything about the initial value of the high-security variable secret.

continued execution does not necessarily reveal everything about the high-security inputs to the program: the actual information leaked may be less than expected.


Speci.cally, we require (1) a CCA-secure encryption scheme, and (2) a CPA-secure encryption scheme with an associated smooth projective hash function [12].

the KOY/GL framework requires1 a CCA-secure encryption scheme with an associated smooth projective hash function, something not known to follow from the previous assumptions.2 In particular, our results imply a more e.cient as well as simpler construction of PAKE from lattice assumptions as compared to the recent work of Katz and Vaikuntanathan [22].


All these solutions may became too expensive as backup resources remain idle when no disruption occurs.

some work attempt to recalculate virtual link embeddings when disruptions occur [9].


This operation may determine a variation of some features that make the sample closer to the malicious region.

we will show that this variation can be very limited: the new malicious samples may not cross the boundary of the decision region, thus bypassing the detection system.


At the time this solution was selected and implemented, PGP did not have a whole disk encryption product for Macintosh systems.

in August 2008, PGP released their WDE product for Macintosh.


However, as our experiments have shown this approach often fails to resolve the used class.

pSiOS tackles this problem by including the Ob jective-C sections in its analysis and by retrieving runtime information.


Similar to text CAPTCHAs, the earliest inspiration for the design of IRCs was also a rough, high-level idea: it s difficult for current computers to recognize certain content of an image.

compared to the extensive security study of text CAPTCHAs, the current collective understanding of failure modes for IRCs is limited.


E-P3P cannot prevent untrusted systems or administrator from using PII in an unauthorized way.

it can help enterprises to maintain PII in compliance with laws and privacy policies.


DISCUSSION We have demonstrated that CPU-bound encryption is insu.cient to securely encrypt a hard disk in the face of DMA attacks.

we will now discuss other techniques that allow e.cient, realistic protection against such attacks.


In [7] spatial dynamic voting (SDV) is proposed to infer data demand, similar to our demand model.

they do not present techniques for integrated modeling of phenomenon, demand, sensor availability and preferences as done in this paper.


Since SSRC is a random 32-bit number, the chance of independent RTP streams generating the same SSRC, while small, does exist.

the two keying protocols handle such collisions appropriately.


Virtual machine introspection [16, 31, 26] techniques, described previously, provide access to VM-state in similar ways to our framework.

they focus mostly on observability of software con.gurations or low-level operating system and hardware behavior.


To access the password .le or host keys, the attacker would have to .nd another vulnerability in the ssh server itself and exploit it via these pipes.

an attacker who compromises the Linux OS in the commodity OS side would have full access to the password .le and host keys by virtue of having root privileges.


To be able to measure this in an automated fashion, it would be tempting to simply re-run each sample in our system and compare the observed behavior to this sample s base run.


which just distinguishes between these three cases should be su.cient for many application scenarios.

more complex approaches are possible and desired, which calculate the similarity between two mechanisms more exactly by using, for example, a distance function between authentication methods and a mapping of this distance to the similarity coe.cient.


A trivial network scanner can be implemented with little work.

using such a scanner openly on a global scale is irresponsible and ethically unacceptable.


Encode(pkw,G(b,c),s) The security properties of the TOR scheme then give us the following guarantee: Given the translation table and encodings of s corresponding to b * ,c * , we clearly compute the encoding of s corresponding to G(b * ,c * ).

the encoding corresponding to 1 - G(b * ,c * ) remains pseudorandom.


This allows to reduce the load by roughly a factor of 3, namely any k-tuple of items may be obtained by reading at most lk/31bits from each device.

this solution triples the total amount of storage relative to the original database, which may be very expensive in the case nis large.


The oracle is allowed to use information up to level M. This means that if m> 0, and the oracle can deduce that the while loop will terminate, then the low output preceding the loop will occur.

if m = 0, the oracle must return UNKNOWN.


They consist in identifying signatures of known attacks to compare them to each request and determinewhetheritisanattack ornot.

these methods are settodefault whentheattackis unknownitis frequentthatan attackhas alreadybeendetectedby another organization andit wouldbe useful tobe able tobene.tfrom this knowledge to enrich the database of signatures.


In reality, it is possible that a structural dataset corresponds to a directed graph, e.g., Twitter.

for simplicity and without loss of generality, we assume Ga as an undirected graph.


One of the advantages of using a hypervisor is that it is able to add security to existing commodity code.

the addition of the hypervisor itself increases the size of the TCB since the system is now vulnerable to bugs in both the hypervisor and the original commodity OS.


Thus, without a large amount of accounts, still it is possible to identify existence of campaign, though correctly estimating an impact of the campaign may be di.cult.

considering the results by our longitudinal spam dataset, we believe that those .ndings are also appeared without lack of generality.


Since we do not have demographic information about Carat users, we do not know their location and thus cannot verify this claim directly.

the translated name (transname) of a package can sometimes indicate the local language of the device.


Tenant-provided policy is used to label data, which SilverLine leverages to provide strong enforcement guarantees in addition to data-.ow tracking.

silverLine relies on a modi.ed OS kernel, does not present performance results and does not allow tenants to check whether it is working correctly.


In multicast, as users join and leave a group, remaining members go through a re-key process thereby refreshing the group key [7].

for secure information sharing, such a requirement is extremely un-friendly because members need not be always connected to a server to access the objects.


Since the Renewal Properties are concerned about the status of such authorizations, a decision needs to be made for the user at re-Join time.

objects, being a passive entity, do not have past authorizations at re-Add time and hence renewal decisions need not be made.


Our attack vectors would indeed be mitigated by the proposed approach.

as the authors mention the proposed approach could con.ict with cost-saving consumption strategies.


2.4 Security Challenges with PassTones No system has 100% Security.

software developers can strike a balance between good security and cost effectiveness.


Authenticated booting cannot keep an attacker from tampering with trusted software components.

it allows when used in conjunction with remote attestation for a user to determine whether a computer indeed runs the software he expects.


Because they operate in a relatively closed environment, people tend to minimize their privacy concerns regarding the disclosure of their identity and location information.

the development of location determination technologies within mobile operators architectures may change this attitude.


Note that here we are using an implicit quanti.cation on set variables X and Y. SEAL does not allow quanti.cation over set variables, and the IFEDAC model cannot be expressed in our framework.

as in the case of Asbestos presented previously, it is possible to encode a particular instance of an IFEDAC system where these sets are .xed, and SEAL can be used in a limited way to verify safety when other relations can change dynamically.


Hence, there are formal frameworks developed to analyze the operating system policies and answer the intra-machine accessibility question [17, 3].

these frameworks do not have a networked view of the system and cannot express the inter-machine access control or the network tra.c policies.


The ability to locate services relies on the fact that server programs typically run on known reserved port numbers, allowing those services to be easily found by any visitor; imagine the chaos of attempting to connect to web sites if every web server used a di.erent port for this service.

relocating services to di.erent port numbers is a common defensive strategy for services that should not be open to the public, which is most often done with ssh.The attacker can still locate the relocated service based on the connection negotiation with the host on the relocated port but the e.ort to locate the service becomes more challenging.


RELATED WORK Some solutions have been proposed to increase privacy on di.erent online sharing platforms like exclusively on social networks or webmail platforms.

these solutions either: (1) do not hide that communication is con.dential [11, 8], (2) protect only certain kind of data (e.g., pro.le information or private messages) [43], (3) require the existence of dedicated infrastructure or a trusted third-party, or (4) are restricted to a speci.c platform.


In fact, one can choose a larger inter-percentile range (e.g., 10-th and 90-th percentile) if there are more data samples.

this does not a.ect the asymptotic behavior of the algorithm.


We call {C |.E : t permits (C, E)} the set of acceptable causes and {E |.C : t permits (C, E)} the set of desired e.ects of S. Note that a causality (C, E) is not necessarily permitted by t if C is acceptable and E is desired.

if C is not acceptable or E is not desired we can conclude that (C, E) is not permitted without further analysis.


In the context of this research, we are aware of the fact that it is hard to implement all of the FIPPs without corresponding policy changes supported by Facebook or other stakeholders.

we can investigate the impact of a limited implementation of FIPPs at the front-end where the data exchange occurs at the moment of installing apps, i.e., installation time.


The precision of the call graph could certainly be improved through further static analysis such as inter-procedural control .ow analysis and it would bene.t security.

since all our optimizations are intra-procedural, the precision of the call graph is not critical to these optimizations.


The amount of memory needed to keep a state for each flow can remain small.

for a regular expression with length n, DFA requires O(2n) number of states.


clever attackers may think about using more sophisticated videos.


Credit is used to identify aggressive attackers; during congestion, the credit of an ac  Figure 1: Components of the proposed defense tive client is decreased proportionally to the amount of tra.c it contributes to the congestion.

credit assignment alone cannot deal with distributed attacks where each malicious client sends tra.c at a very low rate.


Since the execl (wrapper function for execve system call) is generally the .rst function invoked by a newly created process, (thus causing the initial page allocation) the execl function takes all the performance hit induced from the initial page allocation.

in system call benchmark, the getpid system call is used for performance measure.


Removing each role reduces the cost of creating the role and the associated relationships.

we need to add back some relationships so that user-permission assignment relation and the inheritance relation remain correct.


In case of(1), the test resultispositive only if: fp(D ) .G, i.e., fp(D )nG = fp(D ): if this happens, thereis actuallynodifferencebetweenthe output ofPSIandthat of PSI-CA.

pSI-CA is preferred over PSI since, if the test is negative, less information about Server genome is revealed to Client.


Compared to Foursquare, users of Qype seems to post less comments about locations than Foursquare users as their comments correspond to reviews.

these reviews are generally quite detailed, and therefore can potentially leak more personal information.


The resulting systems have a rather small performance overhead and they e.ectively protect against an adversary that uses precomputed gadget chains during an attack.

a more powerful adversary can also compute the gadget chains on-the-.y: Snow et al.


CONCLUSION Similar to how credit cards reduce the friction of paying for goods and services, Web SSO systems are intended to reduce the friction of using the Web.

our study found that current implementations of Web SSO solutions impose a cognitive burden on web users, and raise signi.cant security and privacy concerns.


Figure 7: Maximum jamming probability against seed (n = lm 4, 9, 25, 49, 81, 121, 169; ls =64; |Ce| = |C2 p| )  Figure 8: Advantage of receivers over jammers (n = lm 4, 9, 25, 49, 81, 121, 169; ls =64; |Ce| = |C2 p| ) Figure 7 shows that the real-time jammer has the highest jamming probability among all jammers.

we would like to point out that the real-time jammer is a strong assumption; such a jammer may have to use special hardware (e.g., parallel computing devices) to obtain the despreading results.


APR-Quad proofs range from 79 KB for 1k insertions to just less than 3.5 MB for 90k insertions (Figure 10).

individual proofs scale linearly with the number of insertions, requiring 194 MB for Time (sec) Poof Size (MB) Figure 7: Inter-block search times during insertion of 10k objects in varying sized dictionaries.


rood n) + s on the history set and get the corresponding history token HT.

hT will not correspond to the same HT obtained on the ju, operation since the history token set was updated.


Here, the global policy is set to force traditional CA veri.cation on all SSL connections.

this user connects to a GitLab versioning server that makes use of a self-signed certi.cate, so they created a command policy entry for git that uses the Convergence module.


[14] proposes to replace ret in ROP with a pop+jmp.

the x86-based approach still relies on the stack to govern control .ow among gadgets and the pop+jmp sequence is rare as detailed in Section 6.


Attracted by strong ROI, more and more companies are driven to migrate to RBAC.

for most companies, creating an RBAC con.guration from scratch is not easy.


Against the .ooding attacker, Portcullis performs somewhat worse than before, since about 15% of legitimate senders do not receive a capability.

the vast majority of legitimate senders that do receive a capability do so extremely quickly (note the logarithmic x-axis).


The access control rules and conditions language introduced in Section 4.6.1 was designed to illustrate the capabilities and usage of idemix for con.guring anonymous attribute-based access control in a prototype application environment.

as idemix certi.cates can be used to formulate any assertion (also identity assertions, if required), idemix attribute-based authentication can support any of the trust management models mentioned; also, in a distributed system where credential veri.ers do not know credential issuers (and their keys) on beforehand, credential veri.cation conditions and rules can be modi.ed to express more general authority delegation and trust management policies (e.g., I accept a credential issued by an issuer satisfying trust or delegation condition Y instead of I accept a credential from issuer X.


After a user enters their phone number, it is sent to the WowTalk server, which in turn sends a SMS message with a 4-digit authentication code to the given number.

the code is also included in the HTTPS request s response which is sent to the application.


Vetting Undesirable Behaviors in Android Apps with Permission Use Analysis Yuan Zhang1 Min Yang1 Bingquan Xu1 Zhemin Yang1 Guofei Gu2 Peng Ning3 X. Sean Wang1 Binyu Zang1 1School of Computer Science, Fudan University, China {yuanxzhang, m_yang, xubingquan, yangzhemin, xywangCS, byzang}@fudan.edu.cn 2SUCCESS Lab, Texas A&M University, USA, guofei@cse.tamu.edu 3Department of Computer Science, North Carolina State University, USA, pning@ncsu.edu Abstract Android platform adopts permissions to protect sensitive resources from untrusted apps.

after permissions are granted by users at install time, apps could use these permissions (sensitive resources) with no further restrictions.


It gives conservative results and can be used in safe-critical applications.

false alarms of spoofing are quite possible due to the abrupt changes on signal attributes caused by environmental noise.


On the other hand, it is unlikely that it is useful to pre-compute the full transitive closure of RBAC96 graph in many practical systems, because the size of E. will be very large.

deciding access requests can be performed far more quickly than in the other three approaches.


For example, someone selling packs that contain a home DSL router and three wireless LAN base stations might install a different, randomlychosen NMK in each pack, to guarantee plug-and-play performance with no user intervention.

here there remains an option for the user to enroll the devices in a larger network by either the Secure Mode or Simple Connect Mode mechanisms.


[41] described a pairing-based forward-secure group signature providing better e.ciency tradeo.s than Song s schemes.

their scheme is presented in an analogue of the static BMW model [8] that does not consider corruptions of the group manager.


Ideally, we would use a ground truth that speci.es the exact object layout in kernel memory.


send a secret enrollment key by e-mail to the claimed e-mail address.

this approach has two problems: .rst, it is di.cult to secure the communication paths; and second, subsequent revocation of the well-known identi.er will not be noticed by the PKG.


3.2.3 Ring Buffer Fast Checking For every enqueueing operation from the primary, we should check whether there is available space in the ring buffer to avoid an over.ow.

performing this check within the DBI is very costly, as it requires backing up the eflags register.


The total infection time is bounded by this number multiplied by the time required to infect a generation.

more complex issues arise: a large list of N addresses must be delivered from some initial nodes, and this may be a signi.cant constraint on speed.


If adversary achieves introducing the same error in multiple identical computations, then this countermeasure is useless.

introducing the same error in multiple locations in a cryptographic device is di.cult.


This solution provides a good security level, as good as it is possible with software mod- ules, assuming that a reboot operation would not go unno- ticed.

updating the signature database becomes a very serious problem because any database update would require the re-compilation of the kernel, a critical and time cons,,m~,~g operation.


Instead, the participants themselves can build dynamic trust relationships and assign permissions to each other by updating their own ALs.

when the set of subjects can change over time, but the resources themselves remain more or less .xed, it is more e.cient to use CLs.


There can be no collusion in each singular computation.

the malicious party can change between computations as long as there is no chain of malicious users that link the generator and cloud this would break the non-collusion assumption.


A VMM rootkit is not hidden in memory unless it implements memory virtualization.

the SMBR is hidden by default due to the MCH redirection of non SMM originated memory accesses to the SMRAM region.


Under this modi.cation, Game G3 and Game G2 are identical until H4(u * ,w * ) queried (after the challenge phase).

in this case, we can construct an adversary C for the GBDH problem.


By breaking down the number of vulnerability reports according to severity, we observe that submissions of high and medium severity vulnerabilities keep increasing during the period of observation.

for low severity vulnerabilities, the number has been decreasing since May 2012.


In this case the constraints posed by the personalized nature of the event, allows the prioritized event expression to a.ect only the users to which the event is addressed to.

the spatial condition might further reduce such set of affected users by restricting it to contain only the ones that at time t, satisfy sc.


This is because we conservatively lower-bound the number of packets missed by Eve in phase 1.

the more conservative we are in picking this lower bound, the smaller the size of the secret that we create given a certain number of terminal transmissions.


This new con.guration thus has more diversity.

this con.guration is actually less secure because now an attacker has more choices in advancing the intrusion.


Similarly, if an attacker does not know where valid memory pages are, then overwriting a data pointer can cause crashes.

if valid memory pages are predictable, then overwriting a data pointer has no risk in causing crashes.


The platform supports signed applications and has a user-accessible option to allow unsigned applications, similar to the Android platform.

signing keys can be purchased with anonymous prepaid credit cards by malicious parties from Blackberry for only $20.


Figure 5 illustrates that for new signature formation, using a simple PIN made the task significantly faster than using a complex PIN.

even when using the complex PIN for new signature formation, participants were faster than when using either of the PINs in EKO signature formation.


Mahalanobis distance previously produced good results in identifying both TCP and UDP attacks [27,28].

mapping the distance to a chi-square distribution requires a normally distributed data set.


{x ' };  pattern s super-graph must be infrequent.

explicit isomorphism testing is still required for exploring the super-neighbors of x if x is frequent or x s sub-neighbors if x is infrequent.