We assume that normal users are law-obedient.

they do not, or cannot subvert the insurer monitoring.


For simplicity, a modified free-space path loss formula is considered.

the path loss, denoted by PL, between the transmitter and the receiver is of the form .4pF .2 PL =PT /PR =..Vc .. ·d .


The density of generated alerts by the IDS is used as an indicator of aggression, which in turn determines whether a signature should be pushed to the prevention system or still be monitored6 .

a signature that is reported frequently by many sites will have a higher virulence estimation than one that is reported less frequently and by a smaller number of honeypots, and is therefore more likely to be pushed to the IDS/IPS sensors.


Intuitively, srelease semantics stipulate that a peer Alice can send peer Carla a fact or rule ¢ directly signed by Bob if (1) ¢ is true at Alice, and (2) Bob lsigns srelease(¢, Alice, Carla) , Carla = Alice , or Carla = Bob is true at Alice.

alice can only send out a formula signed by Bob if she is sending it to herself or to Bob, or she can prove that Bob thinks that it is okay for her to send the message out.


In addition to mapping instructions executed on the processor to operating-system processes, we are also interested in obtaining more information when data is exchanged between the memory and hardware devices.

we are interested in more details about when tainted data is written to the hard disk or sent over the network.


The reason for this is the high system complexity and plenty of subtleties surrounding the design, de.nition and analysis of key-exchange protocols.

though seemingly conceptually simple, the (H)MQV protocols were actually very delicately designed, in the sense that slight changes in the design structure or parameters can lose provable security or even be totally insecure.


The security notion of IBST, formally de.ned in [6], cap tures basically two essential security properties: First, tags cannot be distinguished from random covertexts without possession of the private key.


In our framework, utility companies share data only with customers, and data-sharing with third parties always goes through the customer s repository.

customers are required to trust utility companies only in collection of data, not in sharing of data.


The pre-study phase involved registering and brie.y explaining the participants about the protocols of the study.

the participants were shown consent information, which they had to agree before proceeding with the study.


By construction, vi' s are all integers, and for .b .b any a, b, |a vi - a vi' | = |cob+1 - coa| = 1.

the adjusted virtual tra.c di.ers from the original one by at most 1 unit for any time interval.


We then selected, among the redirection chains in S whose domain was .agged explicitly as benign by the AV vendor, those redirection chains relative to domains that we consider reputable and legitimate.

we picked both popular websites, such as Google and Facebook, as well as less popular sites that appeared legitimate after careful manual inspection (e.g., local news sites).


For example, if TS = SU(s) and ES=SU(t), then s<t is a necessary condition for the implementation of ESS.

the implementation of strategies that ensures TS at time s will guarantee the future ES level at time t. To make the implementation more reliable and convenient, multiple dynamic TSs can be computed at time s1, s2, ..., sk, with si< t for all i.


By combining an adapted OAuth .ow with a smartphone-based key deployment mechanism we achieve a high degree of independence from central authorities and third parties.

only the vehicle owner ever possesses its private key.


To overcome these problems, we develop a new approach that is based on propagating constraints about downgradability of processes.

we keep track of the highest integrity of any output .le that is held open by a process and any of the processes that it writes to.


We implement a prototype of this SCOBA framework to demonstrate its practical usage.

we focus on the customized open-source software on the Linux platform.


This permission allows one to access all objects of class c in the access mode a.

[c, create] allows one to create objects of class c. By default, the sso role is granted all class permissions.


In other cases, attackers rely on simple social engineering scams to infect victims.

the web page tricks users into downloading and installing malicious software without exploiting any client-side vulnerability; an example of this are fake antivirus scams [23].


de/), an e.cient Python module for manipulation and statistical analysis of graphs to implement our approach.

we have implemented the proposed structural and semantic analysis of RBAC models.


We again wish to form a hierarchy of actions in a logical order.

if an individual is prohibited from Reading a resource, then she should also be prohibited from Writing and Deleting that resource.


This is developed and explained further below but at this point we note that the factorizability of the joint density function is precisely the de.nition of independence in probability theory.

each node s time-to-compromise is not distributed independently of the other nodes time-to-compromise.


Meanwhile, we allow this application to request any Android permission.

this application s capabilities are no more than those of the benign applications in application stores.


INTRODUCTION Virtualization technology enables cloud computing architectures to achieve e.cient sharing of system resources between a large number of users.

a cloud computing system consists of a hypervisor that manages several guest virtual machines (VMs) that belong to di.erent users.


you will represent a group preparing to do penetration testing.


Under the de.nition of Qin Theorem 4, the maximum portion of time the system can afford to stay in con.guration C1 is b-1 * 2b[-µ1 +d] p1 = , (22) b-1 c-a + 2b[-µ1 +d] 2a[µN1 -d] which is reached by launching MTD to induce con.guration (GN1 ,ß,.).


More formally, the probability of assigning a category is proportional to that category popularity.

given the choice between two categories, one with twice as many people assigned as the other, it    Figure 3.


One of the most interesting parts for EUDAT is the support for most of the required authentication protocols, bridging the protocols supported by upstream (or external) identity providers, translate and harmonise the user information.

from EUDAT perspective, Unity: bridges OpenID and SAML based identity providers: SAML is used by the linguists, OpenID by the climate 2Note that we did not use the ECP pro.le of SAML to manage command line access as our external IdPs are not exclusively SAML-based and most of the ones that are do not support ECP.


On the implementation side, we provided an indepth overview of the way that ALDSP implements access control e.ciently.

we discussed the implementation techniques (mostly based on query rewrite rules) used to keep access control checking from interacting in unfortunate ways with view rewriting, query optimization, query plan caching, and data service result caching.


To provide security for these summaries, the Sign function produces composite signatures sa,t [j], sb,t [j], each consisting of two elements/signatures.

their .rst elements (sa,t [j][1] and sb,t [j][1]) integrate machine-, time-, and column-/row-dependent values r to mask the summaries as in DVS.


(Such cases have been shown in a previous study [39].)

the corrupted, randomized program transits into the Inconsistent Execution state even though the attacker makes wrong address prediction, and then transits into the Crash state when it executes a faulting instruction  f .


While such methods might intuitively seem to prove knowledge of the secret key, they do not suf.ce to realize the abstract model of [11, 29] in which the attacker actually hands the challenger the secret keys.

not only does this type of proof of possession not su.ce to prove secure the MS-Bo and MS-LOSSW schemes, but there are actually attacks against these schemes if such proofs of possession are used [9].


Byimplementing the fullPUF as independent 1-bitPUFs, there is adirectcorrelationbetween eachbit ofthe challenge and eachbit of the response.

.ipping only a single bit of input would result in only a single bit difference in the output.


We also show an analysis of real-life PRNGs using this security model and we demonstrate how it can help to identify new vulnerabilities.

we show that a full internal state corruption is not necessary to compromise a PRNG, instead only a partial one may be su.cient.


First assume .M * ,sV .|= Ti .. Then by the jj de.nition of |=, we have ....T i(sV ).


experiments reported in [2] state that among 14,212 malware samples, a majority voting-based consensus could be reached only for 2,658 cases.

more than 80% of the samples in the clustering results had to be excluded from the cluster validity analysis.


When four CPU cores are employed, the traffic load of each core scales to about 25% of the total flows.

traffic load decreases linearly with the number of cores increasing.


We also hope that the study of our collected system call traces could become a reference point for future work in this domain.

our results could be used to call into question simple detection proposals that are evaluated on small data sets to determine false positive rates.


2.2 DLMS/COSEM Security Analysis The DLMS/COSEM standard does not specify detailed steps regarding the way to distribute MKs and the GKs in the data transport security specification.

dLMS/COSEM does not guide the design of a comprehensive security features or procedures about how the MKs are to be created in the Central DCS, how the keys are to be shared with a COSEM server.


We believe that a clear understanding of the secure programming primitive s failure modes is essential for both e.cient debugging and for reducing the potential attack surface in the mechanisms built on it.

di.erences in the logic that propagates error conditions to higher layers of the API and the resulting di.erence in error reporting can be very confusing to programmers and reduce their overall productivity, making development more expensive and less secure.


Additional (expensive) approaches, e.g., which incorporate billing information and manual investigation, can then be applied to analyze the detection results to further con.rm the fraud activities.

our method servesasa .rst-line defenseinalerting usersand cellular providers of emerging fraud activities and isolating likely fraud activities proactively and quickly from a large number of call records.


{0, 1}n is the input of C and Y is the input of S. (The set S to which Y belongs does not impact the protocol.)

several metrics used for biometric matching are included in this family of functions: Hamming Distance X = (x1, .


We posit that understanding the subtle issues in security protocols is important when designing a protocol.

understanding a penetrator and the knowledge of different attack strategies that a penetrator can apply are among the most important issues that affect the design of security protocols.


One of the landmarks in the area remains the work of Rushby [21], which clari.ed earlier work of Haigh and Young [10].

rushby provides an proof method using unwinding relations that may be used to show security of a system, and moreover proves that secure systems can be concretely constructed by using an access control discipline satisfying a simple syntactic condition.


If the operation is associative and commutative, so will be the whole fold loop.

all we need to study here is what happens in a single iteration.


While we attempted to prove this protocol was secure and did not .nd any .aw, we recognize the need for further investigation in order to .nd out whether any information leakage is possible.

techniques such as model checking could be use in order to formally prove that the protocol de.ned is secure.


The goal is that this malicious prover can cheat in the attestation protocol within the strict time bound with reasonable success probability but without any interaction with the adversary.

the adversary has unbound resources for preparing the attack but only a tight time-bound and limited computational and memory resources for executing the attack.


R, where U is the set of patients, T is the set of medical record types, and R is the set of real numbers.

the sensitivity function fsen takes a patient identity and a medical record type as input, and outputs a real-number sensitivity value.


INTERRUPT ATTACKS In this section, we present a number of interrupt-related attacks.

we introduce a novel attack that evades all currently available hardware and software protection mechanisms.


Dishonest behavior is more di.cult to detect than in SPA.

in SPA the servers might decide to reject a contribution from a particular user if that user submits too many ratings (above a reasonable number of conditions that an individual or family might have).


This system uses the behaviour of the user to determine the trust the system has in the genuineness of that user.

it will focus on input of the user via mouse and keyboard to avoid the situation where an attacker avoids detection by restricting to one input device because the system only checks the other input device [1, 4, 11, 21].


if a page from one origin includes a script from another origin, the included script is treated as if it belongs to the including origin, and hence it inherits all the capabilities and permissions of the hosting page.


[5], proposed an approach that makes the role mining feasible when dealing with such huge datasets.

using an index referred to as entrustability , they propose to divide the access data into smaller subsets that are homogeneous from a business perspective.


To resolve this technicality, we restrict the set Hints(v)to sets Y(£) that have a short description.

for the purpose of this paper, it is su.cient to consider only the sets Y(£),where a set Y(£) is the set of solutions y .{0,1}.


Wallet holders should not even get traffic data without consent or technical need.

one should not implement a remote wallet as a user proxy, because a proxy sees the user s entire communication (except if it is part of an anonymizer chain).


Suppose that we have an algorithm A that solves Predict3LIN(m, e).

given a random input (M, b = Mx + e) the algorithm A predicts the value bm without reading it.


4.1 No Previous Disclosure by the Family As of today most people have not publicly revealed their genome, we .rst analyze the case where no family member has shared any of his SNPs before the donor makes his decision.


In Android, an application must request permissions to be allowed to access sensitive resources.

it is mandatory for Android applications to present its expected behaviors to users.


We also calculated the percentage of passwords that could be compromised using only the top n most frequent characters.

suppose an attacker limited her search space to the 30 most frequently occurring characters.


Then attacker can decrypt data with his private key.


We assume that the APs have synchronized clocks (i.e., within a few hundreds of milliseconds, which can be achieved with e.g., the NTP [25]) and that they are able to compute public-key cryptographic operations.

we assume that the APs from a same network operator share a public/private group key pair (GK pub, GK priv), where GK pub is known by the users and the service provider, whereas GK priv is only known to the APs.


The most time-consuming operation in Vaidya's is the last step of the secure-logarithmbased protocol, while other operations' computational time can be ignore, hence the time is almost not related to the number of parties.

the efficiency of that method is almost equal to the secure-logarithm-based protocol.


INTRODUCTION Virtual hosting has become an essential service in today s information industries.

much attention has been paid to hosting services that are built on a virtual machine monitor (VMM).


We experiment with one speci.c instantiation of this where the resourceful attacker wants to evade detection with a 90% probability.

the attacker, using his estimation false positive rates are scattered over many orders of magnitude.


Here, we assume that an attacker has a transcript of a successful authentication session.

he can see both the random commitment x = +/-r 2 (mod N), I * , and the response.


However, as virtual machines and, more generally, vir tualization, is increasingly employed on laptops and desktop com puters, running in a virtual machine is not a give-away that the plat form is attempting to analyze a piece of malware.

new forms of malware may paradoxically employ virtualization de tection less frequently.


This causes the Web browser to create an HTTP request, which carries the values in the form of GET or POST parameters.

this implies that the password is sent in clear-text to the server.


CONCLUSION The principle of regularity proposed here for self management of systems, states that foralargesystem tobemanageable it must possess suitable regularities.

this principle identi.es the ability to establish regularities in asystem, as a necessary condition for its self-manageability.


INTRODUCTION Malicious code (or malware) has become one of the most pressing security problems on the Internet.

this is true for bots [5], a type of malware that is written with the intent of taking over a large number of hosts on the Internet.


Rankings were based first on the ratio of kills to deaths and then on total kills.

a student who achieved six successful penetrations of other hosts ("kills") but had his/her own host compromised ("death") six times ranked lower than a student with only three kills and one death.


From a practical side, we give a precise assessment of the Linux PRNGs, /dev/random and /dev/urandom.

we show attacks proving that these PRNGs are not robust according to our de.nition, due to vulnerabilities in their entropy estimator and their internal mixing function.


Node capture attack is considered as major threat in many security solutions for WSN.

in [13] both oblivious and smart node capture is considered for the design of a key management scheme for WSN.


Since identifying actions caused by user agency is not enough, we must contextualize the decision points raised by these actions within the applications that caused them.

we must frame the decision that users face in terms of the concepts embodied in that application.


However, we next observe that the operator spends more than usual time on the database (Td = 10+), we get P (I = true|Fd =10-,H = 8 -17,Td = 10+) = 37.80%.

the unusual event (Td = 10+) signi.cantly increases the intrusion probability.


The set of outcomes O is the set of distributions over the belief states of the agents about the input and output values; that is, O = (~B × ~Bn) n. We wish to implement the social choice function W which always selects an outcome in which, for all agents i, Pr(b{(vi, gi(O)) = f(v)) = 1.

in our desired outcome, each agent always computes the correct value of the function.


).Then the above transformation produces an f-leakage-resilient IBE.

by Lemma 2.4, the resulting IBE can achieve relative leakage arbitrarily close to a µ/µ ,where µ is the bit size of individual secret key skid.


This makes our work signi.cantly different from most of other published papers in .ngerprint fusion area.

this study attempts to address questions like: Are there any differences among various .nger pairs in fusion?


If such a certi.cate exists, use its issuer from the local repository as the next step in the path building process instead of searching for the issuer in the pushed certi.cate chain from the server.

if path checking fails, a second attempt should be made by letting the locally stored certi.cates to take precedence over those pushed by the peer.


This savings in effort and the resulting structure opens the door to do research into adding new capabilities to the enforcement policy to increase human understanding of the impact of changes.

tools that show the impact of implicitly defined actors sets could clearly show the impact a malicious insider could have on an organization.


In order to con.rm the e.ectiveness of our methodology we analyzed also several other access control datasets that are publicly available [11].

we analyzed all the dataset at our disposal with more than 1000 users.


Whileexplicit substitutionhasbeenpreviouslyusedin language implementations, we seem to be the .rst to adapt this device to track data .ow in a concurrent language.

we use explicit substitution both to specify DFI (in De.nitions 3.3 and 3.4) andtoverifyit statically(inproofsof Theorems5.4and5.7).We defera more detailed discussiononthis techniqueto Section6.


When such a policyor policyset is evaluated, an obligation SHALL be passed up to the next level of evaluation (the enclosing or referencing policy, policy set or authorization decision) only if the effect of the policy orpolicyset beingevaluated matches thevalue of the Ful.llOn attribute of the obligation.

an obligation will be returned by the PDP if it is associated with a policywhose decision contributes to the .nal decision made by the PDP, and the obligation s Ful.llOn attribute equals the .nal decision.


To do so, we evaluated with our metric the websites in the following four datasets of domains in the Alexa Top 10, 000: XSSed domains: This dataset contains 1,702 domains that have been exploited through cross-site scripting in the past.

an attacker injected malicious JavaScript on at least one page of each domain.


Delegation relations should become explicit and veri.able not just for prevention, but also for auditability of the system.

a care organisation has to prove to the LSP that a particular mandate is valid.


In the presence of EPT however, we aim to avoid large memory transfers by enabling the memory transfer as follows: The helper module allocates the guest-physical page frames for those virtual addresses that were present in Srd and sends this information to the hypervisor; The hypervisor then simply maps each such page to the host-physical page frame for the corresponding virtual address in the production VM.

this mechanism ensures that a user-level virtual address A of the out-grafted process in the security VM and theuser-level virtual addressA oftheprocessintheproduction VM are ultimately mapped to the same host-physical page(as illustratedinFigure2).Afterthat,thehelperalso ensures that any system call from the out-grafted process will not be serviced in the security VM.


It is noti.ed by the Z3 core component when a string equation is asserted as part of the try-and-backtrack process.

the core component invokes a callback function in the plug-in, providing the abstract syntax tree (AS T ) of the equation as an input parameter.


Our technique derives such a speci.cation by comparing the execution behavior of a known malware against the execution behaviors of a set of benign programs.

we mine the malicious behavior present in a known malware that is not present in a set of benign programs.


In hierarchical RBAC, a user inherits all permissions from roles junior to roles she is explicitly assigned.

a user u is authorized to permission p if .r1, r2.


In our implementation, we measure the informativeness of activities using the entropy of the variable CAR .

we ignore the i-th activity ai if the i-th row of CAR has entropyabove a threshold ..


The system should be able to monitor a malware execution in the bare-metal environment.

monitoring should include the interactions between the malware program and the operating system.


A somewhat better approach than committing to all the attribute values would be to employ range proofs, in particular the ones by Boudot [5], to show that the revealed attribute value is contained in the binary vector.

if the vector looked as (alblc), where b is the representation of the attribute that shall be revealed and a and c are the representationsofthe remaining attributes, onewouldprovidea commitment to a and c and then prove (1) that these have the right binary length and (2) that (alblc) indeed is signed by the issuer (without revealing a or c of course).


While rza focuses on disrupting botnets that use DNS-based C&C infrastructure, it can also assist in cases where botnets are more advanced and use domain name generation algorithms (DGA) or communicate using a peer-to-peer structure (P2P).

rza provides the .rst few steps for remediating advanced C&C infrastructure: (i) identifying DNS-based primary C&C infrastructure, if it exists; (ii) automatically identifying if the botnet has DGA or P2P capabilities; and (iii) automatically identifying the malware samples that exhibit these behaviors to triage binaries for reverse engineering.


In the TW case, the corresponding EER of 38.2% means that only 182 out of the 295 arecorrectlyidenti.edas interesting ,while3707 ofthe remaining9705 messagesarealso.aggedas interesting ,albeit incorrectly.

while Aw fails to .ag 38.2% of all interesting messages as such, only one in twenty-one images that are identi.ed as interesting , actually are.


As we can see, when we rotate the phone 90. clockwise, most of the intersection areas are more concentrated.

even if the error range is wide for the generated hyperbolas, their overlap area e.ectively covers the typed key.


The third proposal (BEDA [22]) uses vibration (or blinking) on one device and manually synchronized button pressing on the other device.

we demonstrate the feasibility of eavesdropping over acoustic emanations associated with these methods.


3.2 Basic Scheme In the basic design, the two guest physical memory spaces are mutually exclusive.

each individual guest physical page can only be present in either the recording realm or the main realm, but not both.


These attributes were specifically chosen to mitigate the previously identified constraints.

two technological attributes and one pedagogical attribute identify the framework.


Second, the framework should guarantee that delegation respects proper boundaries between di.erent domains.

it must ensure that a delegation expressed in one logic, to a domain that uses a di.erent logic, does not a.ect the integrity of the logic in which the delegation is issued, e.g., by rendering it logically inconsistent.


Unfortunately, this is challenging because of a semantic gap [7].

to the VMM, the view of the guest-OS is just the raw bits and bytes of the physical memory and register state.


However, recent research suggests that DAS users might tend to pick weak graphical passwords that are vulnerable to the graphical dictionary attack [12].

user choices of their own passwords would render the theoretically sound DAS scheme less secure in practice for both user authentication and key generation.


These features are represented as binary features and used as input to the associated classifier described below.

for an executable file, the input to the classifier is a binary vector that completely specifies the occurrence of each DLL function in the feature set, i.e., 1 when it occurs and 0 otherwise.


A digital identity has its own life cycle which contains the creation, the usage, the update, and the revocation of the identity [4].

the identity usage involves several steps.


[10] exploited the use of multi-touch to inhibit shoulder sur.ng, with the purpose of enhancing PIN input (e.g., at an ATM-Automated Teller Machine).

for their schemes, a user begins by placing three .ngers of each hand on the interface.


Our scheme allows iterative aggregation.

aggregates from lower level aggregators can be further aggregated by a higher level aggregator.


v and Y = v. Recursively applying this procedure allows us to split a secret s into a set of shares {s1, ..., sm} for any monotonic Boolean access structure.

s can be recovered if and only if one possesses a satisfying set of secret shares.


The attacker in SEGURA s threat model can jeopardize the integrity and authenticity of the communicated packets by executing weak manin-the-middle attacks on network traffic.

the protocols for authenticating digital streams over lossy networks.


to access a single block, the client needs to in reality access O(log2 N/ log .)


Note that some apps may be vulnerable to low-severity content leaks; for example, publicly-available information about a network TV schedule is not as sensitive as the user s banking credentials.

we primarily consider serious content leaks whose exposures are likely to cause critical damages to the user.


Normal expressions are the connection between xfACL PDPs and the external applications.

normal expressions are used to describe and retrieve the required attribute values from applications that are further applied in the context modi.cation and the authorization evaluation.


In the next section we introduce preliminary concepts and de.nitions concerning digital identity in a federation.

in Section 2.2. we illustrate the approach we adopt to establish digital identity in a federation for both servers and users.


[30] showed that Vanish can be defeated using low-cost Sybil attacks on the DHT.

they exploited one of the design .aws of Vanish, namely the assumption that DHTs are resistant to crawling.


We compared the results of the replay for each policy with our ground truth annotations.

we introduce the following methodology for evaluating the e.ectiveness of a policy.


The granularity is important for reads and writes only.

from the standpoint of enforcing the Chinese Wall security policy, a read and a write must each constitute a state-change, and is atomic.


No two binders in f bind the same variable.

(every binder de.nes a unique variable.)


If at some point of time, a place ßi contains all the tokens that for the same user complete the entire set of permissions PSi required to infer object xi, transition CompletedTuplei .res.

completedTuplei is triggered when a user has acquired all the permissions in PSi of inference tuple (PSi,pxi)i.


As the amount of other-site code decreases as we move from s to d to w , the number of dynamically created taint values also decreases, at about the same rate.

a large drop in other-site code leads to a correspondingly large drop in the number of taint values created.


CONCLUSION We have shown how Hidden Credentials have features not found in other credential systems.

alice can be assured that her complex disclosure policies will be ful.lled without conveying any information to her about Bob s credentials or even his ability to decrypt her message.


As shown in Figure 3, we must consider the machines that are in the attack graph (reachable by an attacker through some number of attack steps) as well as machines that are in the network model but not in the attack graph.

for reachable machines in protection domain , with domains, the total number of reachable machines is .


The goal here is to .nd sets of code patterns that always appear together during server execution.

if one code pattern from a set of code patterns appears in an execution of ext2, then all the other code patterns from that set appear in that execution as well.


4.3 Protocol Distances between simulated samples and the predicted distribution were recorded for each of the 5 generations.

for generation 1, the distance between pd1(A)and ad(j) was recorded for the 1,000 simulated samples for that generation.


In other words, it is really hard for the intruder to deceive the intrusion detection algorithm.

the intruder has to keep its RSSI value under the RSSI value threshold in order to deceive the Physical layer.


It is also worth noting that, in this case, the Random approach is totally ine.ective.

no change in the objective function is observed for this method, and the number of clusters increases linearly as the attack proceeds.


We derived the number of people for our simulation areas by using LandScan [2] data to derive an accurate estimate for the census population of the area.

we simulate a 9 block region of Chicago with 9056 people, and a 16 block region of Dallas with 2988.


Web applications have a specialized trust model, and therefore specialized construction techniques are used to exploit this trust relationship.

replication is used by Jif/split to boost integrity, whereas Swift uses replication to improve performance and responsiveness.


This in turn depends directly on the relative values of back-o.s used by the attacker and by the legitimate nodes.

the attacker competes with thenodethat has selected thesmallest back-o.


For supporting the BYOD policy in an enterprise environment, virtualisation approaches have been proposed.

trustDroid [21] and MOSES [45] support lightweight virtualisation where corporate applications and data are con.ned in a security domain not accessible from any other applications the user has installed in her device.


definition 3. has(U,R) is true if: there is a role X and can-play(U,X) and hold(X,R'), and R' 2 R or  there is a delegation of the form delegate(x,U,R') = A and R' 2 R  has(U,R) is true if, by direct right or by delegation, user U has the right R, or a stronger right.


analysis based on formal methods would be a useful complement to the analysis described here.


It thus appears well motivated to investigate the hardwarebased solutions.

several content .ltering techniques have been proposed to used Field Programmable Gate Arrays (FPGAs) for taking advantage of the hardware parallelism and the con.gurable nature of the device [4][5][6].


First, we add to the community s understanding of the factors in.uencing IDS usability.

while prior work has focused on the challenges associated with the monitoring and analysis phases of IDS work, suggesting that these phases are the most cognitively demanding, our results show that the deployment phase also involves challenges, and that these may be signi.cant enough to hinder the very adoption of an IDS within an organization.


By keeping this issue in mind, it is, therefore, possible to speci.cally craft the return address and indirect jump/call protection blocks to make sure they do not contain any convenient gadgets.

we discuss the techniques we used in our prototype implementation and the number and type of gadgets that are left in the applications compiled by our tool in Section 5.5.


3.1.2 Delivery Rate The speed at which a collection of nodes can process and forward a message is the delivery rate.

bottlenecks are discovered by comparing injection rates with delivery rates.


We need actions that change policies: locking the door means changing the policy of the door (it will now require a key).

actions can change the state of an entity, and policies are associated with states; 2.


Iflength .lteringisnot enough ornotpossible,thenonecan .lter on the basis of causation : assuming no network congestion, a response is expected to be seen almost instantly afterthepacketthatcauseditwas receivedby thegateway.

with su.ciently high probability, the attacker can expect to observe the response within a short time interval of the packet having a correct ESP trailer being sent.


Informally, we say that this kind of protocol is deniable if the transcript of its execution can t permit a third party to verify the participation of A.

the transcript of the interaction cannot be used as evidence that A took part in the protocol (i.e.


However, none of these schemes is transparent.

they require modi.cations either of legacy applications or the underlying Operating System (OS).


X = {x1x2...xn}, a user can send a query for the ith bit in the database and the server will learn nothing about index i [19, 20].

a PIR protocol provides a means to hide the access pattern from the server [21].


A user will not reveal his/her private share to the PKG or RA since this share also serves as his/her private key in the identification protocol illustrated in Figure 4.

a user should not collude with the PKG since doing so will enable the PKG to calculate the master secret s. Another advantage of the proposed infrastructure is that it provides convenience in key distribution.


BASIC CONSTRUCTIONS In this section we present constructions that can be used as building blocks for designing authentication schemes for a wide range of query types.

we design techniques for authenticating dynamic vector sums (Section 4.1), dynamic matrix products (Section 4.2), and dynamic dot products (Section 4.3).


We observe that numerous malware categories, including spyware, keyloggers, network sni.ers, stealth backdoors, and rootkits, share similar fundamental characteristics, which lies in their malicious or suspicious information access and processing behavior.

they access, tamper, and (in some cases) leak sensitive information that was not intended for their consumption.


Looking at the utility induced once we include the LD correlations in the privacy quanti.cation, we notice some increase in the utility.

including LD enables the donor to reveal more SNPs than without LD.


Originator related roles address special characteristics and functionalities of an originator.

the originator role (OR) abstracts a set of speci.c roles such as the resource owner (OW )who owns the resource; the resource administrator (AR)who is responsible to de.ne the access management policies for the resource; and the resource initial disseminator (ID)who triggers the initial resource dissemination process.


In what follows, we assume that in the lookup tables of all certi.ed proxies, empty entries only belong to non-existent role numbers.

for each valid role, the information of at least one proxy is stored.


In this paper, we propose a speci.cation-based intrusion detection framework to provide high visibility of the semantics of the data carried by the proprietary network protocols.

we adapted Bro [7][8], a real-time network traffic analyzer, to integrate parsers of proprietary network protocols, such as DNP3, used in electrical power grids [3].


3.1.2 Derivation from Interaction Models Figure 13 shows an example how we use the XMI representation of interaction models to identify role engineering artifacts.

figure 13 highlights an excerpt of Figure 6 and shows what role engineering artifacts can be derived from the respective XMI representation.


Oppnets differ from all the typical networks because the size and locations of all the nodes except from the initial nodes (called seed nodes) cannot be predicted.

the seed oppnet, which is pre-designed and consists of certain nodes, is first deployed [2].


Ubiquity of human and other genomes creates enormous opportunities and challenges.

it promises to address one of the greatest societal challenges of our time: the unsustainable rise of health care costs, by ushering a new era of genome-enabled predictive, preventive, participatory, and personalized medicine( P4 medicine).


From the results, we also successfully uncover two zero-day malware, i.e., GingerMaster [14]and DroidCoupon [23].

gingerMaster is the .rst malware discovered in the wild that makes use of a root exploit capable of rootingAndroid2.3devices.


The usefulness of de.ning punishment with respect to typical utility functions is perhaps re.ected in three-strikes laws.

the standard penalties that apply to the .rst two convictions might be viewed as punishing violators whose utility functions are ranked as most typical (according to a ranking).


If the certi.cate were to fail this test the message would be printed to indicate where the problem lies.

the test framework also supports regular expression compar isons, for example: unlike($x509->sig_alg_name, /md5/i , Message digest MUST NOT be MD5 in new CA certs (2.2) ); the signature algorithm name must not match md5.


It is not clear that the techniques of [27] can be e.ciently extended to our setting.

the natural extension in which one instance of a protocol from [27] is run for each record results in linear communication and doesn t o.er the privacy of our protocols since the server knows when each record is queried.


k PIR is a useful building blocks in other cryptographic protocols.

pIR has been used for various special-purpose secure computation tasks such as keyword search [10], distance approximations [13], statistical queries [7], and even for generally compiling a class of communication-ef.cient protocols into secure ones [23].


Limiting hardware resource requirements is the main design issue when using DFAs to perform regular expression matching.

two aspects have been studied in the literature.


For the comparison, we make the same assumptions made in [5].

we exclude the overhead related to the CA's certificate, and assume a 1200-bit RSA modulus N and a 128-bit hash function.


Initially, for instance, a clear distinction of security-relevant data was missing and, while TMI actions naturally supported STM functionality, we had to explore several options to .nd the support for .exible STM and TMI combinations that is present in the .nal semantics.

the .nal semantics provides a a clear separation between TMI and STM actions, which allows STM actions to be lifted to the TMI level and ensures correct behavior when nesting TMI and STM actions, or several TMI actions, one within another.


Note that for each pattern, all the partitioned segments except the .rst one must be anchored, to guarantee the concatenate matching for adjacent segments.


As these cryptographic techniques mature, they may open up new possibilities for cloud computing security While in many cases more research is needed to make these cryptographic tools sufficiently practical for the cloud, we believe they present the best opportunity for a clear differentiator for cloud computing since these protocols can enable cloud users to benefit from one another s data in a controlled manner.

even encrypted data can enable anomaly detection that is valuable from a business intelligence standpoint.


If V fails to meet those expectations, the security of the process followed by S is as if SAuth was not in place at all and S was operating alone.

as S does not nullify its own authentication system, even if V implicitly or explicitly misbehaves, S will not be negatively impacted.


That is, servers are assumed to follow the proposed protocol in general, but try to .nd out as much privacy information as possible based on the users inputs.

we assume the servers are more interested in learning user s private information, such as access habits, history of past movements, and access privileges, rather than user s secret information such as private keys.


We assume that Alice and Bob have additional privacy requirements.

neither Alice nor Bob want to reveal anything about their tuples not in the intersection.


In an e.ort to address some of these consequences we consider the e.ect of using a di.erent model for the aggregation of permissions within the hierarchy.

we assume that permissions can be inherited in one of three ways within the hierarchy: by more senior roles, by less senior roles and by no other roles.


However, all information accessed by an application like Sana may not be sensitive.

information downloaded from a public health advice portal need not be protected.


In fact, there is much active research in privacy-preserving technologies which make services possible while protecting privacy.

preserving location privacy stands out in this .eld because location information is one of the most sensitive attributes for user targeting and personalization.


The limitation of behavior-based detection mechanism can be attributed to the absence of decisive semantic information from the exploitation scene.

the information they gathered are so general that the characteristics of these information are not typical enough for attack detection.


There are 525 unique mediator entrypoints across all programs in these VMs (i.e., a program may appear in multiple VMs).

161 entrypoints are common across all VMs, which is approximately 50-75% of the mediator entrypoints in each of the infrastructure VMs.


However, the sender and receivers use different strategies to decide what spreading codes to use during broadcast communication.

our approach customizes the generation and selection of spreading codes during DSSS communication to defend against insider jamming attacks.


Also, the average number of IDS detected sessions in each day was 6,690.

from Figure 3(a), we can see that the number of IDS detected sessions of only 6 days (i.e.,1@) is extremely larger than the other days.


Predictability Given a state-change in an administrative model for RBAC, it should be obvious what the effect of that state-change is.

there should not be side-effects that are surprising.


We denote by x the input for the .rst player, and by y the input for the second player.

the input x is a set of edges that contains exactly one edge leaving each vertex in an even layer, and the input y is a set of edges that contains exactly one edge leaving each vertex in an odd layer.


The strength of our concept lies in its generic description of the security goals and the abstraction from technical details.

the change in high-level policies can be immediately propagated to the managed system.


Unfortunately, the downside of using managed code was that fact that it was signi.cantly more dif.cult to use lowlevel Windows functions.

it was dif.cult to invoke the Windows API functions that implement the interception of keyboard events (as discussed in the previous lesson).


In the discussion of this paper, we follow the quad-tree model presented in paper [14] for the variation of Leff (.L).

.L is distributed into multiple levels where there are di.erent number of grids allocated on each level.


While early policy models associated permission directly to users, the RBAC paradigm interposes roles between users and permissions.

permissions are assigned to roles and roles are assigned to users.


Similarly, it engages in a.rmUA.u.r and behaves like RBAC(UA{(u, r)}, PA) afterward.

a.addUA.u.r adds the tuple (u, r) to UA and a.rmUA.u.r removes it from UA.


Given ciphertexts, an attacker can try to deduce information about the encrypted plaintexts.

for an ASE scheme, knowledge about the (un-encrypted) master trapdoors or message-dependent trapdoors will provide additional advantage to the attacker.


Infact,alltheadversary candecideiswhetherornot toincludethat tokenin his attack messages; this bounded form of in.uence ensures that the adversary cannot simply manipulate a single feature to have a large impact on the detector s performance.

it was not possible for a small number of emails controlled by the adversary to only use a small number of featuresinorder todamagethe.lter.


In this paper we build on our previous work and extend this approach to provide a support system for Public Key trust infrastructures deployment.

we enhance the peer-to-peer protocol to support (1) interoperable PKI message exchange among CAs, and (2) usable federated identities deployment.


A total of 514 alerts was reported of which 219 correspond to real infections of malware in the university network.

167 instances of spyware and 18 downloads of malware binaries were detected in the network tra.c.


Our .rst .nding is that non-equivocation is unable to reduce the number of processes required to solve Byzantine agreement in an asynchronous system.

we prove a lower bound of 3f +1 processes to solve agreement in a system model that considers both Byzantine faults and non-equivocation.


Programs were tested using a script that randomly selected elements of their user interface over an 8 minute period in order to exercise the application.

the script was designed to open files if such a menu option was available.


This attack eliminates the reliance on the stack and rets from return-oriented programming but without scarifying its expressive power.

under this attack, we can build and chain normal functional gadgets with each performing certain primitive operations.


5.2 IdemixEvidence Togenerate evidencefor a claim withtheidemix technology, we assumeit only contains expressions that are supportedintheimplementation extended with our proposals as described in Section 6.

for idemix this means that a claim must not contain disjunctive expressions, while all other constructs are supported.


In this case, he/she only needs his/her version of the content.

there needs to transmit only one variation in each segment in the content.


For example, the service dependency is indicated by the solid arrow between engines shown in Figure 1.

the device engine provides basic platform resources, which include a user interface, debug connector, a radio transmitter and receiver, random number generator, the International Mobile Equipment Identity (IMEI), and a Subscriber Identity Module (SIM) interface.


In the case of burst attacks, some strategies and methods are quite sensitive to attack parameter optimisations.

the lowest QoS for each defensive strategy is achieved when the BIT is set such that the queue is .lled with a single burst.


Figure 6 illustrates the work .ow of our pro.le matching authenticator.

the pro.le matching scheme works at the packet level, which minimizes the latency of the authentication process.


4.3 Protection of Non-Possession Sensitive Credentials Recall that if C* is a non-possession sensitive credential for Alice, then we have the following scenario: Alice has C* .

false and a policy PC* to control to whom she is willing to disclose the denial policy for C*.Alice will admit the fact that she does not possess C* only if Bob has satis.ed PC* .


Furthermore, since the maximum counter value is ßBF + a, counters will all be empty if the size of the virtual .ow = (ßBF + a)· n. (A tighter condition is if the virtual tra.c size = (maxj cj)* n - j cj, but this requires keeping track of the sum of all counters.)

eARDet can simply reset all counters to zeros and avoid any update if the virtual tra.c size exceeds a certain threshold.


3.7.1 Con.dentiality The time-to-compromise any component i in a classical monoculture by multiple, parallel attackers is the smallest of n samples of a random variable distributed according to f(t).

this is the 1st order statistic, t(1), and, as is shown in the Appendix, E(T(1)) .a as n .8 where a is the leftmost value in the support of f.a is the largest value (supremum) for which f(t) = 0 for all t<a.


The following code (similar to the GNU C library (glibc-2.7) to_lower() function) is used to obtain the lower case value: [1] attributes = transl_table[kbd_data]; [2] lower_case = attributes->lower; In line 1, to get the address of attributes, a non-tainted pointer (transl_table) is combined with a tainted index, kbd_data and the pointer is dereferenced.


Summaryof Expandable Gridfeatures Our Expandable Grid interface has several features that we expecttoprovideadvantagesoverthe list-of-rulesWindows XP .le permissions interface.

the Grid interface has these features: Whole policy.


DecRs (n) - 1 These ideas can be extended to compute a linear regression y = ß0 + ß1x and a sample correlation rxy.

since the problem of estimating ß0, and ß1 can be obtained PPPP P from the sums: x, x 2 ,y, y 2, and xy as follows: PP P y · x - n · xy ß1 = PP ( x)2 - n · ( x2) and PP PP x · xy - yx 2 ß0 = P ( x)2 - n · x2 and P PP n · xy - xy rxy = pP PpP P n · x2 - ( x)2n · y2 - ( y)2 It may also be useful to compute maxima or minima.


However, we allow multiple classes for roles and users.

c has two subsets: Cr, which gives the set of all role classes, and Cu, which gives the set of all user classes.


Intuitively, P (p|r, i) measures how relevant (when i =1)or irrelevant (when i =0)the purposep is with regards to the requestor r s tasks.

whether r is supposed to claim the purpose p.For example, it may be rare for a research institute to claim the purpose emergent care .


Hence, we require a spatio-temporal constraint on edge (u, r).

rBAC = is not su.ciently expressive for cer- ST tain RBAC96 con.gurations and spatio-temporal requirements.


If the hypothesis is correct, however, choice of the subsets will be correlated to the actual computation.

the second round bit will be 0 in all traces in one subset and 1 in the other.


= p 3We do not wish to elaborate further on the nature of per The most important innovation in our model is that each permission is oriented (with respect to inheritance) and can be either up , down or neutral .

p is the disjoint union of the sets P + , P - and P 0,where P + is the set of up permissions, P - is the set of down permissions and P 0 is the set of neutral permissions.4 Each permission p .P is available to some subset of roles in the hierarchy called the e.ective roles of p and denoted RE (p).


We generalize formalizations in section 3.1.

the model in (10) can be rewritten (for weighted undirected graph) as A = [ajk]n×n here, n = |V| where L (i) (i) (i) (i) (i) = w(v, v), v~ v. G.i.


It then computes the skewed value of the simple average of all sensor readings and commands the remaining compromised sensor node to report such skewed average as its readings.

all but one compromised nodes distort the simple average of readings, while the remaining compromised node reports a value very close to such distorted average thus making such reading appear to the IF algorithm as a highly reliable reading.


However, unlike UMTS and cdma2000, our scheme can achieve nonrepudiation between an MS and a VLR.

any dispute between an MS and a VLR can be resolved in our scheme.


However, existing digital signatures are not practical for resource-constrained systems (e.g., wireless sensors, RFID-tags).

traditional signatures (e.g., RSA, DSA) require expensive operations (e.g., modular exponentiation) that bring high computational cost and powerconsumption.


In the law enforcement category, the primary concern is obtaining admissible evidence, necessitating the use of robust techniques that will withstand the scrutiny of the legal process.

[6] the processes by which evidence is obtained and analyzed must be documented, reliable, repeatable, and explainable in terms understandable to the members of the court.


Each string .eld is represented as a single encrypted element while each nu merical .eld of size s bits are represented with s encrypted elements.

one numerical .eld of size s bits is equivalent to s string .elds.


We say that a policy (task,f) is monotonic if the term f is monotonic, i.e., if a userset X satis.es f, then any superset of X also satis.es f. A monotonic policy can be enforced either statically or dynamically, whereas a policy that is not monotonic cannot be enforced statically.

to statically enforce a policy (task,f), one identi.es the set of all permissions that are needed to perform the task, and requires that any userset such that users in the set together possess all these permissions satis.es the term f. one de.nes static safety policies, each of which takes the form sp(P,f),where P = {p1,··· ,pn} is a set of permissions.


Indeed, the entire .eld of autonomic computing is built upon this philosophy of being inspired by biological capabilities but not be limited by biological implementations.

the high-level metaphor of biology is helpful, not the details.


Moreover, A,  the A in this SDH tuple is, perforce, the same as that in the ElGamal encryption (T1,T2).

the extractor recovers the same A that a revocation-checker matches.


As future work, we will address some remaining open research challenges, outlined in Section 5, in our ongoing projects.

we aim to integrate e-health card systems or alternatives into privacy domains and address usability problems in this area.


Some previous work has been done on encoding sparse data.


The result shows that there are still many private .les for every keyword, more than 500 in average.

the number of private .les involving web accounts is obviously more than others, referring to the top 3 keywords password , mail and account .


As a solution to this problem, we propose TrustDraw, which is a security service for the cloud that securely stores identi.ed critical data in a co-resident trusted VM and only temporarily inserts the critical data as long as it is required and not longer.

the critical data is only inserted into the VM s memory if certain previously de.ned integrity conditions of the cloud user s VM could be met.


An issuer is probably innocent if from the attacker s view the issuer appears no more likely to be the originator of the query.

the probability of each user in the anonymity set to be issuer should be less than 50%.


(2) Manageability requires suitable regularities suitable to the type of system to be managed, and to the management technique to be employed.

this principle does not call for any universal regularity, but for regularities that .t the system to be managed, and the management mechanism to be used.


The rule-of-thumb BGP policy for choosing inter-AS paths is the minimization of the network s operating cost.

whenever several AS paths to a destination are found, the minimum-cost path is selected; e.g., customer links are preferred over peer links and over provider links.


The motivation is to provide inherently better coverage than blacklistingbased approaches (e.g., correctly predicting the status of new sites) while avoiding the client-side overhead and risk of approaches that analyzeWeb content on demand.

we explore the use of statistical methods from machine learning for classifying site reputation based on the relationship between URLs and the lexical and host-based features that characterize them.


While we discuss just three speci.c features for account matching, there are others that an attacker can exploit in a similar way.

content may indirectly reveal further personal information that can help guide the matching process, such as Happy Birthday greetings from friends that reveal a person s birthday, even if she does note make the date itself publicly available.


In this paper, we focus our attention on the problem of collusions, in which some parties may collude and share their record to deduce the private information of other parties.

we consider a general problem in PPDM - multiparty secure computation of some functions of secure summations of data spreading around multiple parties.


De.ning security strength using the maximal probability of attack is not very descriptive.

elimination of possible attacks, except the most probable one, does not change the overall strength of security.


We restrict the general concept of usage control in the following way: only trusted applications are run and the underlying assumption is that these applications will not violate the policies.

we do not implement the usage restrictions at the level of Java API or operating systems calls but rather assume that this is done by the trusted applications (this assumptions can clearly be justi.ed in the running example of this paper).


By comparing with the attacks, we can see that the stages as well as the constraints intrinsic to these attack strategies are mostly captured by these graphs.

though showing some potential, these experimental results also reveal a limitation of the attack strategy learning method: our method depends on the underlying IDSs as well as the alert correlation method.


4.2 Provider Resource Database The Provider Resource Database needs to be expanded to accommodate the needs of cloud security.

it needs to store two types of information subscriber identity and service security level which are discussed in the following subsections.


{0, 1}m as input if m  yiUji >Z, i=1 where Z =20ck is a threshold parameter.

s(y) consists of the indices j for which the jth entry of UyT exceeds Z. Theorems 1 and 2 summarize the basic properties of the above construction.


When the list of the attribute references is empty, the corresponding attribute does not appear in any role that is certi.ed by a credential.

the attribute is uncerti.ed by any authorities.


Similarly, the degree of anonymity is about 0.13 and 0.97 (and anonymity is 2.14 and 15.97) when using community-aware and community-blind algorithms, respectively.

the community-aware algorithm decreases the anonymity by 13.83 additional bits compared to the community-blind algorithm.


We have to provide the adversary with all attributes such that the above policy is not satis.ed.

it can be provided either with attributes in ß1, or with attributes in ß2 and so on.


For each bit, we do a simple majority vote.

the of.cial PUF result is the result of the consensus of the three executions.


An immediate motivation for understanding how much variation exists among the shellcodes for an exploit is to inform the state of our defenses.

polymorphic shellcodes are considered to be an Achilles heel for exploit-signaturebased approaches [9, 10, 22].


[1, m]) represents the comparison result of attributes Ai and A'i.

bi = fi(Ai, Ai'), where fi() is a comparison function for the type of the i-th attribute in the  ID Time PID DestAddr Request (Q) Host Referrer (R) Q Type R Type ParentID ... 4 5 6 22.723 22.733 22.973 2724 2724 2724 64.30.224.103:80 198.82.164.40:80 198.82.164.40:80 / .../combined.js .../matrix.css www.cnet.com i.i.com.com i.i.com.com N/A www.cnet.com/ www.cnet.com/ website javascript css NULL website website 0 4 4 ... 14 25.307 2724 198.82.164.40:80 .../bgBody.gif i.i.com.com .../matrix.css multimedia css 6 ... Table 1: Original network events observed.


As discussed in VMST [14], this enumeration is often application-speci.c and has to be done by kernel experts, not the end users of our E X TE RIOR.

after manually examining all the syscalls, we classify those of our interest into the following three categories: (1) Inspection In order to recon.gure the OS or recovery from an attack, we have to introspect the OS to get its current status and perform the response.


Carman, Kruus and Matt have analyzed several approaches for key management and distribution in sensor networks [5].

they discuss the energy consumption of three di.erent approaches for key establishment pre-deployed keying protocols, arbitrated protocols involving a trusted server, and autonomous key agreement protocols.Basagni et al [2] discuss a rekeying scheme for periodically updating the group-wide tra.c encryption key in a sensor network.


Most organizations have secured wireless connections, but if users are bringing in mobile devices, they should be aware that some of these devices might emit a wireless signal that serves as a connection to other devices.

the mobile device turns into a router with open wireless connections.


In particular, the idea is to de.ne security policies as rules (see Section 4), whose antecedents state conditions on SNKB, and consequents specify the authorized actions.

we propose to encode the authorizations implied by security policies by means of an ontology, obtaining the Security Authorization Knowledge Base (SAKB).


matrix computations, particle in cell codes, and .nite di.erence on a lattice, to examine what resources these computations needed and what future architectures would have to provide.

few studies have utilized supervised learning algorithms to understand performance logs of high performance codes.


The Stackelberg equilibrium is a pair of choices (f * for the LPPM and h * for the attack) such that neither the user nor the adversary would gain anything by changing their respective choices.

h * is the choice that minimizes privacy against f * , and f * is the choice that maximizes privacy against an adversary who will make her choice after observing f * while respecting the quality constraint.


X1 = x1 X1 = x2 X1 = x3 32/100 2/100 2/100 X0 = x1 12/100 12/100 12/100 X0 = x2 2/100 6/100 20/100 X0 = x3 Figure 5: H2 n(b) (lower graph with stars), H1 n(b) (upper graph with stars), log22 (b) (lower graph with W n W n circles), and log21 (b) (upper graph with circles), with b = (010101010101), X0 = X6 = x1, X2 = X8 = x2, and X4 = X10= x3 for the joint probability distributions given in Table 3.

how entropy and guesswork changes with the number of encrypted units, i.e., the encryption level This is done for languages up to the second order by deriving equations for entropy of selectively encrypted messages and then transferring the result to guesswork through an equation relating the two measures.


KEY PREDISTRIBUTION USING RAN-DOM SUBSET ASSIGNMENT In this section, we present an instantiation of the general framework by using a random strategy for subset assignment during the setup phase.

for each sensor, the setup server selects a random subset of polynomials in F and assigns their polynomial shares to the sensor.


Research on PUFs [15, 16] arose from the observation that distinct instances of hardware produce unique behavioral characteristics [28].

each copy of the device, even if designed to be identical, will exhibit slight variations that can be measured only during execution of the circuit.


An RBAC policy P is subversive if there exists any execution with P that transitions to an authorization error state under the base instrumentation, but not under the modi.ed instrumentation.

p is subversive if suf.cient under the modi.ed instrumentation, but insuf.cient under the base instrumentation.


We believe that our schemes o.er attractive features and argue that social networks would bene.t from its implementation.

they enable a centralization of friend relationship data and friend group data in a single SNS and reusing these relationships at other SNSs or external service providers for access control.


End-users could see a catalogue of potential access privileges that they could request, and security administrators could identify and correct inappropriate privileges.

security administrators would be freed up to become security analysts, engaging in questions of how roles should be built and structured, which was expected to be bene.cial to the organization in terms of both e.ective identity management and employee retention.


To facilitate action execution-level enforcement, we also consider the privileges assigned to a user and the time interval during which theyare assigned.

knowing what privileges are not available, we may identify history information that is extraneous to enforcing particular security properties.


the .rst messages of A and B are sent (in a random order), followed by the second messages (in a random order), and so on.


This holds for practical protocol proposals such as Kerberos and publickey infrastructures as well as for cryptographic protocols and for tool-supported protocol analysis.

[2] introduced a rigorous cryptographic treatment for protocols analyzed hitherto only based on unproven abstractions.


Then, we can easily evaluate the power-sum symmetric polynomials Enc(pk, Pj(x1,· · · , xn)) for 1 = j = d with only an additive homomorphic property, and evaluate symmetric polynomials of degree d by decrypting Enc(pk, Pj(x1,· · · , xn)) s and multiplying and adding on the decrypted data.

this method is more e.cient when evaluating low-degree symmetric polynomials in many variables.


Assume now that ClickMiner failed to mine the node Y.

y = (py, ey, qy) is missing from the click graph C. Also, suppose that the network trace contains an exchange (qy, ry), for which qy s URL equals refu.


4.3 Discussions For both low and high security applications, our analyses show that after a certain number of login sessions, the probability of successful impersonation into the system in choose-two scheme becomes higher than the probability of successful impersonation in choose-one scheme.

as the passwords are used over and over again, asking two passwords per login session becomes less secure as compared to asking one password per login session.


The harder problem is to incent good user behavior and business practices.

if there is no way toquantifybehaviorthatisdirectly correlatedwithdata breaches, there would be no fair fee and hence no incentive for users and businesses to change their practices.


3.1.5 Role Activation with Contexts Role-based systems usually treat roles as static attributes or at least attributes that change infrequently.

we might not allow the following scenario: A hospital employee work as a doctor in the morning, as a billing clerk in the afternoon, and then as a doctor again the next day.


R, rs_acquires(u, p, r, s, t)  It is important to note that can_activate(u, r, t), can_acquire(u, p, t), r_can_acquire(u, p, r, t) and can_be_acquired(u, r, t) predicates do not assume anything about the state of a role.

they do not say in which state role r is at time t. For example, if can_activate(u, r, t) and enabled(r, t) hold, then a user u s request to activate r at time t is granted provided there are no other activation or SoD constraints prohibiting it.


However, a key problem that has not yet been adequately addressed by existing role mining approaches is how to propose roles that have business meaning.In order to do this, we provide a new formal framework that also enjoys practical relevance.

the proposed framework leverages business information such as business processes and organization structure to implement role mining algorithms.


An additional 1996 p facts are used to achieve a fan-out factor of 5 [21].

for each p fact with the .rst argument ai, where 1 .


If the conventions of orthodox PKI were to be applied to this operation, then a number of additional complexities would be imposed from outside on how the stock exchange runs its business.

most PKI regulators today would expect standardized identity proofing for all certificate recipients at a level equivalent to passport application, irrespective of how the existing listing rules operate.22 Furthermore, the company officer, as certificate Subject, would generally have execute a user agreement with the CA.


To ensure the isolation between the legacy host and the isolated environments, SICE prevents the legacy host from a.ecting the execution of the isolated environment, and the isolated workload (excluding the security manager, which needs to be trusted by the legacy host) from a.ecting the execution of the legacy host.

we need to prevent the interference through explicit inter-core communication as well as those through modifying each other s memory.


Given that the role of friend is applied uniformly across all friends of an actor in the Facebook network, the permissiveness of this norm (Norm 1) and the Friends of Friends norm (Norm 2) are self-evident.

the capacity to over-share or experience inappropriate .ows of information is high.


One approach to reduce the effect of blocking calls and network latency, is to increase the number of parallel operations performed by the proxy.

increase the number of OpenSER child processes.


In this paper, we present the current work-in-progress of our dynamic integrity measurement architecture (DynIMA).

our contributions are the following: We propose a general design for a dynamic integrity measurement architecture (Section 3).


For example, action add(PA, (buy(book), Engineer)) is supported in Li/Mao, but the second-order administrative action add(PA, (add(PA, (buy(book), Engineer)), Manager)) is not.

the syntax of actions supported by Li/Mao is like that of Fig.


For clarity, we .x the .nal Q-bits of the hash output as the target string.

for a given puzzle with (Q, D), a solution x should satisfy (h(x) mod 2Q) : D. For instance, if SHA-1 is used and (Q, D) = (32, 65537), then a string x is a solution, only if (SHA-1(x) mod 232) : 65537.


Inthispaper,weintroduceseveralnovelattack techniques targeted at major websites, as well as modern browsers, email clients and other comparable tools.

we illustratethatSVGimages embedded via  tag andCSS can execute arbitrary JavaScript code.


Role-based access control (RBAC) [30], attributebased access control (ABAC) [34], federated identity [27,32], trust negotiation [4, 5, 36], and distributed proof [3, 19] systems all assess the trustworthiness of a user based upon veri.able and unforgeable statements regarding the identity, roles, or attributes ascribed to that user by one or more trusted certi.ers.

these trusted certi.ers serve as roots of vertical chains of trust associated with a particular principal.


The .lter(s) could simply be added as an additional stage in the existing spam identi.cation infrastructure.

the .lter veri.es the email s annotation and con.rms the statistics it contains.


Compiler optimization may also complicate the implementation (and debugging) of sandboxes.

modern compilers support intrinsic functions, also called builtins, that are implemented by the compiler and available for use (implicitly) by the user program.


However, this path includes the possibility that the security label of the object and subject are equal, in which case the PDP would allow the request and the SDP would deny the request.

the SDP is not consistent, as it has denied a request that the PDP would allow.


However, this relationship does not imply the inheritance of permissions.

a user with salary 2000 need not get higher privileges than the one with salary 1500.


The results of U-test revealed that subjects rated their concerns differently for only six data types (out of 32) .

subjects expressed more concerns about an insider threat for SMS messages, call history, browsing history, and search history in the browser.


More formally, we de.ne an information-.ow policy as a triple (C, =, dom) where (C, =) is a bounded lattice over the .nite set of domains (or security classes) C, = is a partial order on security levels.


This type of quadratic state problem cannot be solved by an NFA-based approach.

the corresponding NFA contains 1042 states; among these, one is for the matching of SEARCH, one for the matching of s+, and the rest of the 1024 states for the counting of [^n]{1024} with one state for each count.


For graphs of dimension d > 1, an e.cient data structure can also be built using dimension reduction techniques.

[5] shows that, given a solution to the one-dimensional graph, a data structure for a graph of dimension d will have an extra factor of O((log n)d-1) in the space complexity of the data structure, and extra 2(d-1) edges in the maximum distance between any nodes (between which a path exists) in the data structure.


We analyze the privacy properties of our method and show that in many cases, the information about raw user data that must be given to the identi.cation system is minimal.

privacy of contact information is always preserved, and even the communication pattern can be hidden to some degree.


For a discrete random variable X, the min-entropy of X is related to the most probable value that X can assume, speci.cally minentropy(X)= -log2 (maxx Pr[X = x]).

if min-entropy(X)= e then X does not assume any value with probability of more than 2-£ .


Moreover, as in the statistical evaluation, Lux0R substan tially outperforms PjScan in terms of classi.cation accuracy.

when our detector was trained on PDF sam ples exploiting only CVE 2007-5659, more than 96% of mal ware samples exploiting other vulnerabilities, i.e.


A CONCRETE MODEL As we saw in the previous section, in the abstract model, determining the accountability of a system can be done ef.ciently provided several restrictions are placed on the system.

one requirement was that actions perform state transitions that cause the set of enabled actions in the system to either increase (with respect to .


Assuming that a node has amassed su.cient (read perfect) evidence, various approaches have been introduced that require di.ering amounts of participation from other nodes in the network.

revocation decision making may be the result of a collaborative, systemic or a unilateral decision process.


Leveraging these ties, it is possible to design ef.cient and distributed algorithms that, with a moderated degree of node cooperation, enforce the emergent property of node capture detection.

in this paper we provide a proof of concept proposing a set of algorithms that leverage, to different extent, node mobility and node cooperation that is, identifying social ties to thwart node capture attack.


The piece of information provided by the principal RA in the Open() is therefore necessary for the decryption of the veri.able encryption.

it must contain a secret piece of information without which the veri.able encryption cannot be decrypted up to the security of the underlying encryption method.


Recent news underline that control-.ow attacks are a severe problem on smartphones.

control-.ow attacks can be utilized to steal the user s SMS database [11], to open a remote reverse shell [8], or to launch a jailbreak [5].


Our route attestation tags are also a sequence of attestations by routers, but here we allow the attestations to be more general public key authentication methods.

an attestation may be either a signature or a set-membership proof.


Speci.cally, di.erent from prior out-of-VM approaches, the monitor in our case no longer needs to walk through external page tables to identify the physical addresses for examination.


(We show some attacks to illustrate this point below.)

rule(iv) allows trusted processes to protect unprotected objects by raising their labels.


As a compensation, a tireless attacker devotes more time and labor in the attacking process to maximize the chance of success.

a tireless attacker knows some of the attributes of his/her target (seed attributes), and submits such attributes to search engines, and tirelessly browsing and examining the results for clues.


The depth of the cascade Bloom .lter generated in the .rst strategy, where m is set initially to 1 million counters, is always 2.

constructCascadeBF always has enough space to allocate to the counting Bloom .lter of the .rst level of the cascade, and can afford to have just one more level, which is the explicit list.


TCP port 135 is used by the Windows DCOM RPC service which has been the target of several vulnerabilities and exploits.

tCP port 135 is the infection vector for the well known and still prevalent Blaster worm.


One of the signi.cant functionalities of GS-MDO is that no interaction between the opener and the admitter is required.

tokens can merely be published by the admitter, and once the opener receives the token, he is able to open the signatures without any further interaction with any other entity.


this mapping identi.es an element of F16 with a bit string.


We implemented the FVDS scheme in the OpenSSL open source cryptographic library [29], both as a standalone signature scheme and for use in the SSL protocol (we discuss the latter issue in the next section).

we modi.ed OpenSSL version 1.0.0 to support FVDS using the builtin big-integer operations, and compared the performance of this scheme with the built-in RSA implementation.


An adversary able to make decryption queries 5.1 De.nition of HCE and obtain an unlimited number of arbitrary credentials does not have a non-negligible advantage in forging a credential he has not obtained.


As such, one of our primary concerns is ease of prototyping and .exibility; in this setting, rewrite-based approaches are very useful.

implementing our approach only required understanding the browser s AST data structure, and none of the complexities of the JavaScript runtime, which allowed us to quickly build and modify our prototype as needed.


For a particular scenario, once the privacy needs, objectives and requirement are defined, we have to characterize the most suitable solutions.

we have to identify: - the type of solution to develop: is it an organizational procedure, a cryptographic algorithm, access control, or a combination of subsets of these solutions?


In the proposed scenario, an adversary is assumed to possess a small piece of seed information about a targeted user, and conduct extensive and intelligent search to identify the target over both the Web and an information repository collected from the Web.

two types of attackers are modeled, namely tireless attackers and resourceful attackers.We then analyze detailed attacking mechanisms that could be performed by these attackers, and quantify the threats of both types of attacks to general Web users.


In particular, we only assume an upper bound on the number of corrupted sensors; thus, it is not possible to map subsets of the polyhedra while guaranteeing that the fusion polyhedron contains the true value.

such mappings would require additional assumptions on the number of corrupted sensors in certain subsets of N (t); hence, all permitted actions in this work are: a) computing fusion polyhedra for all n polyhedra in a given time step; b) mapping this fusion polyhedron to the next time step; c) or mapping all polyhedra to the next time step, thus doubling both n and f .


The decision for a request is then obtained by composing the decisions from all applicable policies with at least one decision from the terminal policies in one department.

if all applicable mandatory policies allow the access request and at least one terminal policy allows the request, the request is authorized.


9 See RFC2693 for more details about how to use keys as the only names for keyholders.


While SaaS collaboration has numerous advantages, it also raises new security challenges.

since SaaS collaboration is increasingly used across enterprise boundaries, organizations are concerned that sensitive information may be leaked to outsiders due to their employees inadvertent mistakes on information sharing.


However, none of these coding techniques were designed for security reasons and the security services are o.ered by the higher layers of the UMTS network stack.

both spreading and scrambling codes can be brute-forced as their search space is not large (and the assignment of spreading codes on the uplink is almost completely speci.ed in [3]).


While optimized implementations for speci.c named curves and .eld degrees can provide high performance, it is a desired security feature for both ECC software libraries and hardware accelerators to support elliptic curves over a wide range of binary polynomial .elds GF (2m).

the implementer of an ECC library or hardware platform may not know all curves that will eventually be used.


This may be due to the fact that SVM and k-nearest-neighbors algorithms utilize a vector space model in the classification process.

they are capable of taking advantage of the pairwise distance preservation characteristic of the random projection technique.


This coincidence allows lifting without much di.culty the isolation result of earlier work [10], which does not consider the cache.

the unwinding lemmas of [10] can be used mutatis mutandis, without the need to be reproved in this extended setting.


The transition in business processes introduce new security challenges.

as autonomous and selfgoverning administration exists in individual domains, authentication and access control mechanisms need to consider access from external users in e.cient and scalable way with least trust to external entities.


These may be dynamically constructed by the web application.

headers may incorporate content that was initially supplied by an untrusted user.


Anotherpossibility isthatthe con.rmation succeeds,but a subset of ActivatedRoles have become disabled.

the user has con.rmed both his location and his identity, so there is no chance of a false-alarm as above.


However, communication is not that reliable in the typical RFID environments.

transmissions are susceptible to delays and they might also be incorrect,e.g., in the case of collisions.


The computation cost for V is little changed from that given in the above analysis with batch veri.cation; however, the bidirectional communication cost and P s computation cost are both much improved.

while V must now send n. extra bits to P (i.e., the small exponents a1, .


For security considerations, we adopt multiple email services at the same time.

when Client A wants to publish some private data such as profile information and messages in Mailbook, he/she will encrypt the data and disperse it to a certain number of email services.


Consequently, the placement of nodes in a network plays a crucial role for the effectiveness of intrusion detection techniques.

the nodes should be placed in such a way that the radio range of inner network nodes is completely covered by surrounding network nodes.


In TD, unlike in PD, the entire authority that the delegator role embodies is delegated.

all the permissions that he can acquire (through assignments and inheritance) are made available to the delegatee.


Nevertheless, Fr turns out to be a complicated condition.

fr would not be insensitive to addition and deletion of pre.xes , a feature often attributed to fairness constraints [22].


To apply Theorem 4.1, we require that the depth of the decryption circuit is smaller than the depth of the circuits that the scheme can evaluate.

log qlog N · (log log q + log n)  0, which holds for the parameter settings in the statement of the theorem.


MAIN CONSTRUCTION Our main construction of a privacy ampli.cation protocol is obtained by building an improved authentication protocol with low entropy loss.


Fusking or Fuskering is a procedure where a program is able to do a brute force type of attack where it uses typical filenames to guess the next logical file to appear in the sequence.

if you have an album that contains multiple photos named pic01, pic02, and pic03, but sent someone only the link to the first one; if they assume that those others exist, they can then use the same link and substitute the next logical name or number and it would display the file if one existed.


Note that correctness still holds even if the circuit C completely ignores all ciphertexts encrypted under a public key pki ., or if none of the original ciphertexts were encrypted under this key.

using super.uous keys in the decryption process does not a.ect its correctness (as long as decryption uses at most N keys).


We counter this criticism of ourdesign with thefollowingjusti.cations.

first, attacking the Ri values in this manner can only occur at S. the Ri 2 values are never transmitted in the clear where an attacker can eavesdrop.


We propose to use probabilistic generative models for risk scoring.

we assume that some parameterized random process generates the app datasets and learn the parameter value .


This assumption requires a small eavesdropping setup that can be easily carried by the attacker and a real-time identification of the leakage parameters.

the contributions of this paper are as follows.


However, it might be possible to employ the same type of side-channel analysis to detect Flush-Reload attacks, similar to the ideas of HomeAlone [39].

a victim might be able to infer the presence of an adversary by means of performing Flush-Reload monitoring of the cache to detect the Flush-Reload pattern induced by an adversary s likely choice of NFA.


Diagram 5(a) has been obtained by considering, for each Di , all the range queries whose edges are a half of the size of the corresponding dimension of Di .

we considered queries of size 1 · V ol(D) (that is 12.5%) in the 3D case, 1 · V ol(D) (that 23 24 is 6.25%) in the 4D case, up to 21 7 · V ol(D) (that is 0.78%) in the 7D case.


For future work, we plan to continue interviews with various stakeholders during ongoing usage of the IdM system in the insurance organization.

we are interested to learn whether the organization achieves the expected bene.ts.


However, routing and bandwidth bottlenecks are fundamentally di.erent as they do not necessarily imply each other.

routing bottlenecks are unrelated to the available bandwidth or provisioned link capacity, but closely related to the number of routes served by each link.


Based on a pilot, a threshold of 0.5 cm was used for the minimum gesture length.

a gesture had to be at least 0.5 cm long from touch-down to touch-up, to be considered as a gesture.


Then, as was brie.y mentioned earlier, having this structure expands dramatically the type of functions that can be computed.

one can see that matrix multiplication on matrices with encrypted data is easy to compute.


UNIFORMLY RANDOM PUBLIC VIEW We .rst consider the e.ectiveness of an adversary in our model if the graph is produced by uniform random sampling.

given a request for public neighbours..(..), the network responds with a random selection of .. of the .. s friends, or returns all of their friends if ..(..) = ... We assume that the network responds deterministically to each request, providing the same set of friends every time public neighbours..(..) 1 ..(..) /..*(..) i. the sampled graph includes false edges.


Given some suspected colluders, their sequences and the pirated sequence, build a more accurate estimate of the collusion channel.

as we better estimate the collusion channel, we better accuse dishonest users (i.e.


e consider a scenario in which an SP is modeled as a server, which provides a service only for a legitimate user.

we can assume that the GM has authenticated a user before issuing a signing key, and the SP can judge that the user who can generate a valid group signature is a legitimate user.


For any valid (s, L) that is hold by a credential holder UH , he can only designate the credential s to any veri.er that is listed in L, speci.ed by the credential issuer.

there exists no algorithm for any (s, L) that will allow the credential holder to designate s to a user UO .. L, such that T rue .


Declarative semantics [13], on the other hand, is what you see is what it is.

there is a more direct speci.cation of the meaning associated with something expressed in the syntax.


Physical fairness assumptions, such as resilient channels, must be re.ected in the formalizations of the security protocols that aim at liveness goals.

the resilient channels assumption can be seen as a fairness constraint for the attacker model.


Our attack highlights the nuances of properly designing traceability algorithms by demonstrating how it is possible to take advantage of a seemingly benign discrepancy between the ciphertexts that are emitted during the traitor tracing operation compared to the ciphertexts used during normal transmission.

our attack capitalizes the fact that during regular transmission in the scheme of [9] each ciphertext transmitted by the sender can be decomposed into parts by the illicit decoder, one part for each traitor key, and that each component can be submitted to a statistical test that returns a random bit.


For example, in the role graph model it is generally assumed that no user should be assigned to MaxRole [13]; (U,{MaxRole} ,s) expresses this constraint succinctly.

we can express role exclusion constraints: such constraints can also be used to impose a ceiling on the roles to which a user can be assigned.


Current DRM systems focus mainly on right-holder s security needs and commonly neglect those of consumers.

these systems even lack reliable means for users to verify that they purchase usage-rights on works (licenses) from the rightful authors (rights-holder).


According to [13], up until 2008, this research .eld was relatively new and had not been thoroughly explored.

in the setup of diverse ensemble members, only two combining methods were considered for one-class problems: the .x-rule [42, 18] and meta-learning [29] ensembles.


16 applied to interaction obligations in the manner illustrated in Fig 6.

each function is applied to all interaction obligations in a diagram and each interaction obligation on the concrete level is a translation of one and only one interaction obligation on the abstract level.


One scheme that encompasses the above properties is the Paillier cryptosystem [26], which we use in our implementation.

the Paillier cryptosystem is a semantically secure additively homomorphic encryption scheme, which can be used as a threshold scheme [18, 11] whose key generation can be performed in a fully distributed manner [4, 12].


Consider an alternative (hypothetical) de.nition of policies in which a policy has the following function type instead: L×L×U ×U G(I, L) × G (J , U) .

2(6) a policy takes a spatial network and a social network as input, and produces a 4-ary relation that relates an owner location, a requester location, an owner and a requester.


We note that the class C N C0 is limited in computational power.

it is contained in AC0, and so there are simple and natural functions (such as XOR) that cannot be computed in CN C0 .


5.2 Performance Evaluation We quanti.ed the performance of the lightweight secure TPMS communication protocol.

we focused on the performance of two phases: TPMS data session and the session key update.


If T is in fact noticeably less than q, a simpli.cation of this is a close upper bound: N * (T/q)m (2) T As shown in [1], Equation 2 not only re.ects the probability of the existence of such a coalition of size T ,it isalso the probability that a larger completely di.erent coalition could have incriminated this coalition of size T when this coalition is actually completely innocent.

the formula gives the false positive probability in the detection.


This relation depends on a local reduction relation, ., that describes the reduction of expressions under an environment and a pool of threads.

call and return programs reduce under -., and all other code reduces under .. Of speci.c interest are (Red let-return), (Red send), (Red call), and (Red return), that can cause data .ows across contexts.


Therefore, we exploit the semantics of the access control policies presented in [5].

in [5] we have de.ned the semantics of the protection object speci.cation of a policy acp as the set of tuples over which a user to which the policy applies can exercise privilege acp.priv.


We introduce a new set of constraints for variables aij yij .

we create a random coe.cient matrix Qi .


We then determine the range of time over which this activity occurred and, within that interval, identify which sources appear to have contributed to the activity.

we apply this approach to the problem of detecting distributed SSH brute-forcing: attackers employing a number of systems that each try different username/password combinations against a site s SSH login servers, hoping that one of them will stumble across a working combination made possible by a careless user.


More importantly, notice that the instruction distribution of the English encoding is most like the instruction distribution of the randomly chosen Wikipedia articles illuminating the di.culty of distinguishing English shellcode without considering syntactic information.

it is not clear (at least to us), how to easily mitigate this threat without considering the semantics of the input.


While these browser extensions provide control over cache-based tracking and visited link tracking, we show that there are limits to user control over tracking from cooperating web sites.

although cookie policies provided by some browsers may suggest otherwise, we argue that it is not feasible to allow multiple-session tracking by a single site without also allowing multiple-session tracking by any collection of cooperating sites.


Given this description, we then obtain the following:  We put forth a su.cient coding theoretic condition for ExEG schemes to have an e.cient traitor tracing algorithm.

our condition requires that the key-space of the ExEG scheme forms a linear code that is e.ciently decodable.


Most authentication systems use some form of Positive Authentication (PA) to identify legitimate users.

these systems use a password profile containing all of the user passwords that are authorized to access the system (or the server).


However as already noted, those approaches attempt primarily to answer questions about how much a program leak and seem unable to scale to real code in terms of line of code, state space and language constructs.

they have not, as far as we are aware, been used to analyse independently existing vulnerabilities in independently existing programs.


In doing so, we have attempted to adhere to the original implementation as closely as possible.

the manner in which theAccessToken(seeSection3.4) isimplementedis crucial to the time-e.ciency of CPOL.


DESIGN AND IMPLEMENTATION Due to legal considerations, we did not resort to directly evaluate an existing DCG captcha implementation (e.g., are you a human DCG captchas).

developing automated attacks against these captchas directly violates the company s asserted terms and conditions [5].


discuss a number of challenges related to the evaluation of results generated by malware clustering systems.

by using plagiarism detection algorithms to measure the similarity between malware samples, they show that a factor contributing to the strong results reported in [2] might be that the 2,658 validation instances selected via majority voting on multiple AVs are simply easy to classify.


It is easy to determine whether a set is ineligible when the set of constraints only contains constraints of the form ( =,S1,S2) or of the form (=,S1,S2), when S1 is a singleton.

we have the following simple result, illustrated schematically in Figure 4.


Aread/write(R/W).ag is maintainedineachpagetableentry(PTE),describingthe R/Wproperty of thepage mappedby thePTE.Thisallows thesamepagetobe mapped with adi.erentR/Wproperty in di.erent PTEs.

writability is a property of the mapping of a page, not a property of the page itself.


Since the discount is a resource, the head of this policy, BookSt.discount(phoneNum = x3 ), de.nes a part of the application interface provided by the ATN system using this policy; the parameter phoneNum is made available to the application through this interface.

the application will issue a query to determine whether the requester satis.es BookSt.discount(phoneNum = x3 ), and if it succeeds, the variable x3 will be instantiated to the phone number of the requester.


Our protocol, which builds directly on the protocol of Feige and Kilian, is qualitatively more practical than known techniques for delegating computation in the single-server setting.

all known protocols rely either on arithmetization and PCP techniques [20, 12], or provide only amortized performance advantages and rely on fully homomorphic encryption [11, 9].


Once we have described such a system, we then de.ne and analyze the problem of users gaining unauthorized information about future events.

we focus on future events because concealing actions which are presently happening is much more dif.cult and would require either more drastic measures or, in some cases, measures outside of the control of the security system.


The main disadvantage of misuse detec- tion systems is that they can detect only those attacks that are known.

they can detect only attacks for which they have a defined signature.