This extension preserves the security properties of Octopus in that the node-link relationship remains the same and hence the content key can be obtained by possessing a directed path from the Personality node to the User node (via the Domain node as the intermediary).

it is assumed in our implementation that the shared domain is managed locally by a domain manager that the service provider trusts.


One of the most promising applications is the dissemination of commercial advertisements via car-to-car communication.

due to non-cooperative behavior of sel.sh nodes or even malicious ones in the real-world scenario, such vehicular advertisement system cannot be realized unless proper incentives and security mechanisms are taken into consideration.


The game, as outlined above, might only be able to capture a limited number of training samples (PINs) to be used for the classi.cation of the unknown PIN.

as has been shown in 2012 by Bonneau et al.


3 The RM uses Firefox s SOP implementation, so it handles domains like cnn.co.uk.

the SOP alone does not prevent JavaScript in two different zones from colluding to leak con.dential data; a script in one zone can communicate with a script in another zone using cross-domain channels like the fragment-ID channel and postMessage described in Section 4.3.


This method works by representing those patterns as a set of signatures to be compared against packet contents using exact matching algorithms.

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


We already performed the formal analysis of this model assuming relaxed knowledge.

due to space limitations, we do not detail the analysis here.


In distributed systems, different parties may make connections and do business without being previously known to each other, different resources are shared across organizational boundaries and a potentially unbounded number of users and resources exist with few guarantees regarding pre-existing trust relationships.

the traditional security model, where the identity of all possible requesting subjects must be pre-registered in advance, is not suitable for the distributed environments.


While the top-down model is likely to ignore the existing permissions, a bottomup model may not consider business functions of an organization [9].

the bottom-up approach excels in the fact that much of the role engineering process can be automated.


Unfortunately, again any in-VM responses can be disabled by attackers because they run at the same privilege level.

with EX T E RI OR we support running software out-of-VM, and we can quickly take actions to stop and prevent the attack without the help from any in-VM root privileges.


For example, the Neopets list for the most part represents young children.

the PhpBB list was a development and distributions site for the PhpBB bulletin board so most of its users were webmasters and/or programmers.


However, a client needs to download a key from the server in order to decrypt the content, and WISPr only works for static content.

hTTPi is readily compatible with existing web sites, it supports static and dynamic content, and it adds support for progressive loading and mixed-content scenarios common on the web.


This introduces client-side approaches to counter malicious websites.

end users now need to invest in (hardware) resources to run one virtual machine (with the patch level used on the productive system that has to be protected) and to set up the honeypot and additional control software.


Directly creating such link .les is not possible yet, i.e., Sony Ericsson s JVM throws an exception in this case.

there is an indirect way to achieve the aforementioned goal: The rename() method of the FileConnection API accepts .le names with that special character.


It is also more di.cult to detect as it does not change the actual content of the program memory.

such attack has several limitations as it exploits existing routines only and disappears when the compromised nodes are reset.


It requires only the IPC subsystem to be modified with no reliance on instrumented code, thus it can work with applications that use native libraries.

quire s approach is application-centric not system-centric, and it cannot protect privilege escalation attacks that are based on maliciously colluding applications.


Likewise, the above table shows none of the access control methods, except ours, can support emergency override of default access control policies.

some approaches are reported in the literature that address this issue, either over RBAC (e.g., [28]) or independently (e.g., [29, 30]).


Schulman s work was followed by a .ow of other works [7, 8, 4, 5, 3, 2], culminating in the recent elegant result by Brakerski and Kalai [1] that shows how to e.ciently simulate any interactive protocol in the presence of constant-rate adversarial noise, with only a constant overhead in the communication complexity.

none of these works gives any bound on the value of C(E).


In KRISHNA, in order to compute clusters, each node needs accurate information of the entire network topology, facilitated by network-wide link state update which by itself is extremely vulnerable to node mobility.

we found that both HEED and DECA are quite resilient to node mobility in that they can generate 0 0 5 10 15 20 25 30 35 40 45 50 node maximum speed (m/s) Figure 9.


These results can be explained by a possibly synchronous message delivery mechanism held by the Google service (contrary to the asynchronous service of TMS).

in terms of receive operations the performance of TMS Endpoint is aggravated, as this operation cannot be performed in an asynchronous way due to its nature.


The latter is similar to Packet-in-Packet attacks known from radio systems [12].

this attack relies less on probabilistic errors, and more upon implementation di.erences of the decoders.


The sensors are increasing coverage in a .nite area, as there are more detectors, and increasing potential trackees, as there are more people.

due to the clustering behavior of humans, the increase is not as pronounced as might be expected, as the increase in detectors can result in the same area being covered multiple times.


However, it is evident that for all practical purposes it is di.cult to build a storage system that can satisfy all the listed services.

this list can help system designers to quantify their requirements and evaluate other storage systems.


For example, if u receives v s response to u s HELLO before u responds to v s HELLO, u will suppress its own response.

if u and v .nish their neighbor discovery step separately, in the pairwise key establishment step they will have two di.erent pairwise keys, Kuv and Kvu.In this case, they may choose Kuv as their pairwise key if u<v.


They assume the CSI collection is benign (without the presence of an identity-based attacker) when building the user pro.le.

in practice the identity based attacker could be present at any time.


On the one hand, the identity data are encrypted for the user and the user herself generates the proxy re-encryption key (de.ning which service provider is able to decrypt the identity data).

the user is able to de.ne which data are disclosed before it is sent to the identity provider.


Such botnets have thus a high potential to render targeted services unavailable.

the actual impact of attacks by DDoS botnets has never been evaluated.


CONCLUSIONS It is apparent from the current use of Orbot that the Tor network can be accessed from mobile devices.

based on the .ndings from this preliminary study, there is some doubt to whether Tor can support mobility e.ectively, for an increasing mobile client base, particularly when mobile users are roaming.


The flow cache stores flow states for each flow.

the memory space required by a flow cache is quite large for an FPGA.


The main contribution of our work is to introduce the MP metamodel and specializations of it for personalized access control (in the form of SMAC policies).

another source of originality is methodological: rather than attempting to .nd specialized solutions to access control problems, we aim to identify and formally represent the foundational concepts of access control and to then construct general axiomatic frameworks from which specialized solutions to access control problems may be derived.


The other components can be deployed and run on remote agents.

the communication between them should be well designed as users locations are acknowledged as an important piece of private information.


For example, subjectusersof types1-2haveaccessto most of theinformationthat is processed/recorded by the videosurveillance system.

subject-users corresponding to object-user types3-6(or even usertypes1-2 notin charge of operating the videosurveillance system) should nothave access to these data.


The data revealed no significant difference between conditions.

the low number of participants in this study may have been a key limitation, and this result may merit further investigation.


For the Scaled Manhattan classi.er, the mean FRR of samples collected with feedback is 0.01106 higher than that without feedback.

the di.erence is not statistically signi.cant.


Similarly, for the AFrame activity record, we change the process name, data folder and its hosting process record.

for the state of the current activity, we can keep the value since the AFrame activity always shares the same state with the main activity.


The Cardblock [13] Trojan em beds itself within a pirated copy of InstantSis (a utility to extract SIS software packages from a phone).

cardblock sets a random password on the phone s removable memory card, making the user s data inaccessible.


Sen [18] proposed a general decentralized monitoring of safety properties in distributed systems.

to the best of our knowledge our work is .rst one to study the de.nition and enforcement of distributed stateful security policies.


The rules is AUX de.ne the assignment of a speci.c agent to a speci.c status level on the basis of the agent s actions or ascribed status.

each of PLA, PLD, ACC,and AUT H is used to express an organization s policy as it applies to all agents with a particular status.


This problem cannot be used for a replay attack because clients will still be able to at least detect the gap during the read counter operation.

it does make all counters before the power failure untrustable (because client devices would not have proof that these counters were not incremented during the time slot of the gap).


While we admit it is practically possible to create sucha view-generating function within the monitored guest OS, view generation using knowledge of the hardware architecture is always best done externally for one primary reason: Any view-generating function that makes use of hardware architectural knowledge canbe implemented fromwithin the VMM and gains allof thebene.ts associated with such an approach (i. e., isolation, consistency, etc.).

implementing a view-generating function in the guest OS brings no advantages over an approachin which the function is implemented externally.


Today s  operating systems of mobile devices offer authentication mechanisms.

they are either vulnerable in some situations or not user friendly enough to be widely adopted.


There are some published hints about the inner structure of the WRNG [11].

the exact design and security properties were not published.


It is very likely that performance could improve on all devices when users type in self-selected passwords.

our participants were highly familiar with all used devices and their respective keyboards.


A high number of malicious resolvers were found in the IP pre.xes in Russia and Ukraine.

only one resolver was found across the two pre.xes we scanned belonging to the U.S.


This would make users think twice or at least try to read and understand how much information they may allow third-party apps to access.

four participants believed that the MONO design was more aesthetically pleasing and easier to understand.


The exact cost of launching this attack depends on the cloud being considered.

we can provide a rough estimate by using the results of Ristenpart et al.


A policy author concerned solely with expressive power would select Lithium over L5.

the choice becomes more complicated when concerned about the ability to reason about policies, because only L5 features independent composition.


By keeping a secure record of the messages exchanged between components, PeerReview detects when a component s behaviour deviates from that of a given reference implementation.

peerReview assumes deterministic components, which is challenging in cloud environments.


To reach the high depths of knowledge and expertise which are required of them nowadays, scientists focus their attention on minute areas of study; the current paradigm in our jobs is far from the polymath or Renaissance man of ancient times.

the most complex problems we face still need the application of different disciplines to tackle them, which creates a necessity for interdisciplinary collaboration.


At this point, there will be a large one-time addition of authorizations to the allowed list of users.

later, after other friends are added, checking to see if a user has access to a limited number of resources can be done through backward chaining.


In the setting of our work, having some initial trust in data processors is unavoidable.

log servers should not initially have to be trusted.


Many of today s networks, especially those of large ISPs, deploy intra-domain load-balancing mechanisms based on the Equal-Cost Multi-Path (ECMP) algorithm [22]; e.g., approximately 40% of Internet routes [4] are load balanced by it.

eCMP is insu.cient to prevent routing bottlenecks.


We didn t .nd the security condition restrictive in our case studies.

for loops without observations, one can relax the requirement on equal number of loop iterations and ensure termination-insensitive noninterference.


As we will show in Section 4, discarding minor variants is indeed a good heuristic for selecting samples.

we will also show that in some cases executing several almost identical samples can provide valuable information, such as the different C&C servers contacted by each sample.


We observe that most of the positive results came from top 10 results, which indicates that a tireless attacker does not need to be very tireless to achieve a successful attack.

we also observe that positive results do not always come in top 2 search results.


A solution to this problem is the massively popular OAuth protocol [7] that allows a user to grant access to a consumer on his data residing on a server.

the current OAuth protocol suffers from a major flaw: once a user grants access to a consumer, it is possible (with knowledge of the consumer s security tokens) to access the user s data anytime and from anywhere [11].


When we investigate defense approaches, we will discuss how to implement the defense mechanisms in the operating system, on the assumption that attackers cannot compromise the operating system.

1Other possible sensors on mobile phones include accelerometers, which are increasingly popular, and other more esoteric sensors, such as thermometers and barometers.


There are also many works proposed to make further improvements on ABE [4, 12, 20, 21].

all these ABE schemes implement the attribute matching detection only after decryption and hence lose practicability due to large computation cost.


In legacy networks, as the adversary gathers more information and compromises new hosts, the search space shrinks and her knowledge about network enhances, which allows her to gradually move toward the target.

in our MTD network all gathered information is invalidated by moving from one host to another.


As discussed in Section 2, the bad measurement detection algorithm computes the L2-norm of the corresponding measurement residual to check whether there exist bad measurements or not.

if the attacker uses Hc as the attack vector a (i.e., a = Hc), then the L2-norm of the measurement residual of za is equal to that of z,as shown in Theorem 1.


The di.erences between our caching service and a real web proxy are as follows: A web proxy typically only caches static HTML pages and ignores the dynamic HTML pages, and it will not cache responses with the private/no-cache/no-store cache control setting in the request header.

our caching service needs to store every web resources triggered by the analyzer.


By using an automatic tool we are not dependent on the skill or otherwise of security researchers.

if a new class of vulnerability is discovered, we do need to update the tool s knowledge-base to account for it.


{e}) · · · xn update(update({pay}, neutral, 1), confirm, 1) = update(update({pay}, confirm, 1), neutral, 1) Hence independence of events is a choice of abstraction one may make when designing an event-structure model (because one is not interested in the particular order of events, or because the exact recording of the order of events is not feasible).

note that this is not a limitation of event structures: in a scenario where this order of events is relevant (and observable), one can always use a serialized event structure in which this order of occurrences is recorded.


3.2 Conventional Approaches MAC address .ltering, WEP and IEEE 802.1x are used for authentication and data encryption.

none of the three solutions is enough for security and authentication purpose for public wireless Internet access.


Memory sharing of the analysis VM is currently performed before the execution of the malware sample is initiated, therefore memory savings gradually decrease as the analysis VM is executing.

more aggressive memory sharing can be performed by trapping updates made to the guest page tables and evaluating which physical pages can be safely deduplicated.


The IP address is perhaps the most obvious candidate.

if the target system is behind a .rewall the IP address may be neither unique nor known to machines on the outside.


In RepCloud, when all the nodes hosting the VMs of an application are tampered, they may report each other as trustworthy without being identi.ed, and hence tamper the target application.

with the multi-tenancy nature of the cloud, each of these hosts may at the same time host VMs from other applications, which may communicate to nodes in the cloud TCB of the those application.


The categorization does not facilitate any distinctions between devices in the same category.

various research e.orts have shown that improvements in PN functionality result in new potential threats.


In the absence of regulations which assure patient privacy, standards for interoperability may impose designs that limit that privacy.

the focus of attention on potential standards and interoperability provides a rich context of developing systems that can protect privacy as data .ows across multiple systems.


We integrated graphical passwords into Versipass because of the bene.ts of cueing, which will allow users to better remember and distinguish their passwords.

text passwords can also be cued and there are opportunities to improve the security and usability of cued text passwords.


For example, Facebook s documentation states that publishing a story (such as liking an article) requires the publish actions permission.

if the create note permission is requested, publish actions will also appear as a granted permission and this will allow stories to be published.


When directly inputing text into the GUI, they know what they are typing.

when they select items such as an HTML link using the mouse, the end user needs to be told what resource access their selection will require.


Similarly, we cannot infer that the enforcement of a dynamic historical constraint implies that the corresponding static constraint has been enforced.

we can assert that the enforcement of a static historical constraint implies that the corresponding static constraint has been enforced.


To use an existing account to login is faster than to fill in personal information forms over and over again.

many online users, even those who frequently use social login systems, are not aware of the policies and conditions they agree with.


As shown simulation result, the system of code rate 1/3 represents a good performance about 2.2 dB than system of code rate 1/2.

we can see that the system of code rate 1/2 provides a considerable coding gain than uncoded UWB system.


This means that encrypted documents spread around all TVD members do not need to be re-encrypted every time that one member is revoked.

this scheme assumes a central repository for documents.


Ben Sangster Department of Computer Science US Military Academy West Point, NY 10996 at network defense, an information assurance team must ensure intense scrutiny of tra.c, develop fresh intrusion detection rules to prevent new attacks and exploits, and deploy immediate patches for the latest vulnerabilities.

all of this is done within the physical perimeter of the network.


It worked well when the user had de.ned his own definition of a function also provided by a library, typically with the same semantics.

we discovered that this approach introduces problems when the semantics of the two de.nitions are widely different.


Initial inspection indicates the attack graph model may be suitable to measure tamper resistance strength.

this approach does not address important subtleties inherent to software tamper resistance: 1.


In compari son to XXEA, the message has to be a SAML token.

this token does not have to be signed with a valid key nor the signature needs to be valid.


Bots used to have more friends than followers [25], and the ratio is less than one in this situation.

there have emerged some more sophisticated bots that unfollow their friends if they do not follow back within a certain amount of time.


Finally, SIP could potentially use various mechanisms for encrypting SIP messages and ensure 1Note, that other VoIP service providers such as Skype using proprietary protocols would be a part of this ecosystem.


i 1 and go back (a), otherwise it goes to end.

f. Encryption rate The encryption rate r of KMN-PKC is   since V + L of a denominator can be erased if the all of a1, a2, , aJ is set to 0, the encryption rate r is  If such a real encryption rate is considered as a density of the low density attack of conventional knapsack PKC, it will be said that the density of this PKC is very small.


Chunk granularity does not affect monitor code integrity as long as checks dominate unsafe instructions in chunks.

bigger chunks have better security because it limits the space of indirect jump targets.


At runtime android.os.ServiceManager is already loaded by DVM when application is started.

one can cheat the compiler by writing a dummy android.os.


Security level scores, such as CVSS/CWSS scores, can be applied to a cloud computing environment.

evaluation methodologies, such as the CVSS/CWSS formula, are subject to change.


Their work focuses on the use of mobile phones as an authentication proxy between the user and the system that the user intends to authenticate.

this method requires additional development costs to incorporate the technique into system due to hardware requirements.


We show that the original PCA method can be easily compromised by any of our poisoning schemes, with only small amounts of cha.. For moderate amounts of cha., the PCA detector starts to approach the performance of a random detector.


The Panorama project [56] demonstrated the power of fullsystem dynamic information .ow tracking.

the way that address and control dependencies are handled in Panorama is application speci.c.


Such a path (secret key) is not joining-timeoblivious: it depends on when the user, as well as the nodes higher up, join the system.

when encrypting, the sender does not have to know the path.


There was no strong correlation between the values of transformations and the success rates.

less transformed photos had higher scores in several cases.


More recentframeworks[1,3,44] andtheirdiscrete components[15,19] attemptto o.er or mimic alevel oftransparencyanalogous tothat of a non-instrumentedOS running onphysicalhardware.

given thatnearly all ofthese approaches reside in or emulate part of the guest OS or its underlyinghardware,little e.ortis requiredby aknowledgeable adversary todetecttheir existence and evade[26,39].


Tightly-connected social circles where a user s friends are also friends with each other are the worst scenarios for SA, as potentially any member has enough information to solve the SA for any other user in the circle.

facebook designed SA as a protection mechanism against strangers, who have access to none or very little information.


Whitelist redirect URIs: Domain-based redirect URI validation signi.cantly increases the RP attack surface.

whitelisting of redirection endpoints allows RPs to reduce the attack surface and dedicate their mitigation e.orts to protect only the whitelisted URIs.


Therefore, if we use the Gaussian kernel in its pure form, we are bound to use .x-length gait cycles as input features.

if we manage to use DTW distance instead of the Euclidian distance, we could solve the problem of .x-length input feature vectors.


This has the advantage of eliminating the reliance on user-space TCP stacks, leading to reduced implementation complexity and improved performance.

as we show in the next section, the use of a kernel-provided socket for every circuit makes it possible to launch attacks that attempt to exhaust this resource at a targeted relay.


The occurrence of condition (1) decreases FA by increasing F (qid1, qid2).

the occurrence of condition (1) also decreases |qid2|, thus CA.


Currently, the problem of unintended code is solved by imposing alignment based on prior work on sandboxing [35, 36].

it may be possible to replace this technique with the branch-removal algorithm employed by G-Free, while leaving the actual control .ow lock/unlock code as-is.


As in the previous case, it is still possible to discard some candidates for the key during the analysis, even if they are very few, with the consequence that a bigger number of experiments is necessary.

if the fault model includes both the faults of [11] and of its complementary variant (i.e.


INTRODUCTION The use of software-based tamper resistance to protect embedded secrets was once limited to military applications or software companies wishing to protect an embedded license.

with the increased usage of content protection systems by the music and movie industries, tamper resistance is now used in a broader spectrum of applications.


Property 1 in Definition 7 guarantees that there exists a reachable state y1Ethat is equivalent to yqp1; thus ¢1Eis true in ycE1; therefore, the instance in , (ycEE e¢1EE [yBE, e:q), is also true.

if(yEe¢E,yEe:q)is true, then there exists a reachable state y1Ein which ¢1Eis true.


In particular, our previous work MoCFI [11] enforces control-.ow integrity (CFI) on iOS devices running on ARM processors, while CFI [1] has been originally proposed for desktop PCs.

moCFI focuses on runtime attacks rather than application sandboxing.


Both providers marked with U believed either our religious complaint (global-4) or our phishing one (regional-7), warning the website owner about the possibility for his account to be suspended if the offending content was not removed within a few days.

contrarily to what was promised, the content of the websites was left untouched and none of these providers took any action to block the user s account after the ultimatum expired.


In such techniques, continuous time is approximated to some .xed quantum.

events do not always happen at integer-valued times.


This is not desirable from SecVisor s point of view since it now has to trust the BIOS code.

sVM provides a way to address this issue.


When no two malicious routers are adjacent to each other on the intended path before Ri, malicious routers can redirect the packet to any routers as it chooses.

all preceding links on the desired path are still traversed in the correct sequence for this packet to be accepted by Ri.


Overall the visual viewing quality is heavily impaired since a bucking e.ect with blurring is introduced when a su.cient number of temporal frames are encrypted.

when only the highest temporal layer is encrypted the skipping of every second frame is actually nearly not noticeable since the merging of temporally adjacent frames partly conceals the missing frame.


Sometimes, it is useful to obtain the raw sensory data at the aggregator for further processing such as compression or signal enhancement and make this data more efficient and accurate before forwarding it to the destination.

aggregation cannot easily be done directly on encrypted data and as a result imposes an additional overhead on decryption.


Like CoPilot, a separate hardware environment was used to protect the measurement system from the target and to minimize the impact on the target at the cost of having extra hardware installed.

it is subject to the same limitations as CoPilot.


Our scheme aims to enable assurance of the individuality of users more securely.

there are some authentication methods based on PKI, such as TLS client authentication.


In EON, the authors have shown that it is possible to con.gure Asbestos labels in a manner that can cause unsafe behavior.

safe defaults are suggested for send and receive labels.


Before the takeover instruction is executed (cases I and II), the victim process only executes the instructions intended in the original program, though the operands may be corrupted.

after the takeover instruction is executed (case IV), the victim process may have executed instructions injected or chosen by the attack.


At an implementation level, there is a noteworthy di.erence: in [12], every password is fully processed into the strengthening database.

those GP calculations utilized a static dictionary for alphabetic strings, rather than a dictionary dynamically built from the observed passwords.


Possession of the protected content (depicted by the shaded boxes on the top of these .gures) does not permit an attacker to discover the password by trying guesses without involving the TV.

both do allow for on-line password guessing attacks.


Many software nowadays are based on open-source software distributions, which greatly accelerate the software development process.

since the users are in control of all the source .les, they are able to tailor, con.gure and build their own executables to be deployed in their own environment.


The computer industry is combating the rising threat of malicious activity with new hardware and software products such as Intrusion Detection Systems, Intrusion Prevention Systems, and Firewalls.

malicious users are constantly looking for ways to by-pass the security features of these products, and many times they will succeed.


REVOCATION Revocation is the process by which a delegation that was accepted is removed or retracted.

since delegations may be chained, a revocation can produce side e.ects and other consequences.


INTRODUCTION Signature-based detection has been a major technique in commercial anti-virus software.

that approach is ine.ective against code obfuscation techniques.


Generally, the Kullback-Leibler divergence is used to calculate the distance between two probability distributions.

as its non-symmetric and bin-by-bin properties, it is not appropriate to be adopted in our scenario.


Unlike the local rerouting solution discussed in Section 5.1, MPLS recon.guration can perform .ne-grained tra.c steering to avoid collateral damage on the other links.

the widely used o.ine MPLS recon.guration cannot be very e.ective since it can recon.gure tunnels only on a time scale ranging from tens of minutes to hours and days [14, 57].


As explained in section 3.2.3, KD and its protection key are removed from a device when it leaves a domain, which prevents protected Rights Objects from being used by devices in multiple domains.

this does not stop legitimate controlled content sharing; protected content can move between devices belonging to di.erent domains.


FlashOver [7] is a system to automatically scan SWF files for XSS vulnerabilities by using a combination of static and dynamic code analysis.

flashOver does ignore the Flash security issues caused by the xml policy.


Many of those capabilities are defined by the LIAF.

some capabilities are related specifically to the sharing of identifying or authorization-related information.


designed and evaluated an new attack that uses the load of a shared CPU to encode information [27].


Moreover, multi-character NFAs are proposed to improve system throughput [9-10].

instead of focusing on a single flow with continuous data stream, our implementation concentrates more on the traffic in real-world networking with multiple flows.


And if an adversary tapped communication data between the User and the Smart Card in Registration phase, he can have a SVi, SCi and Hi.

he can t know unique value SCV about the Smart Card by this operating value Ti=h(SCV||SCi||Hi) PSi.


For example, the Device Locator service shown in Figure 1 has to generate location queries for devices upon receiving a location query for a user.

for services such as the People Locator service, this option gives the services more privileges than they really need to have.


(This translation, and all server-side functionality, can be sandboxed or otherwise access-restricted to limit the e.ect of any software .aws in the server.)

translation servers have access to a stream of instructions before they are executed by the client, leaving the server uniquely positioned for many possibilities beyond rote translation.


Thus, where static analysis can prove the adversary control of an resource retrieval entrypoint in all cases, the entrypoint is su.cient for RRQ rules as well.

not all information .ows may be derived statically, as some names may only be under adversary control some of the time.


Because the classi.cationdependsonprocessing incomingresponses, RequestRodeo does not scale well to web 2.0 applications, as it sometimes misses some crucial context information, and is not able to detect all dynamically created links in the responses.

stripping implicit authentication and using an external proxy as a means of protecting the user against CSRF is considered to be an important contribution of RequestRodeo, and was a direct inspiration of the approach presented in this paper.


The server only needs to support the poauth_cp_key parameter, keep a record of the consumer platform keys and encrypt data with this key to support POAuth.

there are several ways in which the server can enhance the security and user experience using optional features of POAuth.


In applications with indirect UI-based conditions, some comparison instructions determine whether the sensitive behavior can be started.

the UI event function can assign the values to registers in the comparison instruction.


protection [4]; and attitudes and behaviors [5].

privacy issues are sensitive, difficult to study and poorly understood.


A commonly used method is to use tree indices to improve the search performance.

multidimensional tree indices are normally used to process axis-aligned bounding boxes ; whereas, the transformed queries are in arbitrary convex shape, not necessarily aligned to axes.


If UR is used as a credit card number,it must conform to these restrictions(which may complicate UR generation, depending on the ID number space of UF ).

as such a number is identical to a real credit card number, it can be used in the existing infrastructure.


On the one hand, v * is far from every codeword, as the relative distance of the code is high.

v * satis.es all the edges in G * that are also satis.ed by every vi.


Assuming that the practice using OpenEMR has configured these parameters in php.ini correctly, this Denial of Service attack would fail.

we were able to comment out these parameters, and submit a file larger than 2GB in size after modifying the MAX_FILE_SIZE parameter.


The result shows that the detection rate of the 3D method is only marginally better than ours for both photo attack and video attack.

our scheme has a lower false alarm rate than 3D authentication method (up to 10% difference).


While our protocol has optimal entropy loss, it has a round complexity of T(.).

dodis and Wichs [7] showed nonconstructively that there exists a protocol with both optimal entropy loss and optimal round complexity (2 rounds).


2.2.3 Constraint enforcement Enterprise PKI operators use cross-certificates to establish trust between enterprises and employ a variety of constraints, i.e., extensions, to limit the degree of trust accorded to the cross-certified PKI.

cross-certificates are not always a viable option.


the design, once again, nels up in a black state.

the effectivene;;s of these method::; in producing a wrong output has not been demonstrated.


A security architecture that depends on centralized entities could not face this situation.

sHAD .ts well into this scenario: Nemo s PCM and Eva s PCM can negotiate tickets to allow Nemo s Pocket PC to make contact with Eva s laptop.


Clearly, the repeaters need to know the values (ei, pi, Pi) owned by each node Ni in order to solve the aforementioned optimization problem.

triplets (ei, pi, Pi) reveal considerable information about the households (i.e., the required energy, pricing).


By Proposition 2.7, queries that are unions of conjunctive queries give the same answers (the certain answers) when applied to either y Jor m2J, since both solutions are universal.

consider the conjunctive query with one inequality: n((X o)W:JZy:JZw2(T((XoZy )T( oZw2 )(Z(yW=Zw2))d no y Then returns ((aa)})when evaluated on J, and returns the empty set when evaluated on J2.


5.5 Attestation As mentioned in Section 4.3, the SMI handler should be a part of a trusted boot process.

the LS22 servers, used for our implementation prototype, are not equipped with a TPM.


( ab ) *, we can directly make use Z3-str to generate the possible string assignments for x, then checking membership is straightforward since xis already ground.

this naive approach is likely to be inef.cient.


To address these privacy concerns, one can imagine a solution in which a client records scrubbed data to avoid the privacy limitations associated with reporting detailed logs.

this is an imperfect solution, as evidenced by the large gray area associated with executions and installations of programs that are benevolent but have some vulnerability.


Usefulness: Note that while the trapdoor recovery, which results in ., gives only a random value, it involves performing the costly (computationally intensive) dual-receiver message recovery algorithm R. In our implementation (Section 3.1) this is an operation over the curve (the pairing) and is conceptually analogous to exponentiation over a .nite .eld, if somewhat more complex in terms of the actual operations involved.

the message decryption by the server involves only bit-wise XOR, and a check of a simple hash function (which is much more e.cient).


RFID attacks can also happen at the Domain Name System (DNS)/Object Name Service (ONS) level [17].Because the backend database is often the furthest point away from the RFID tag, both in a data sense and in physical distance, it may seem far removed as a target for attacking an RFID system.

it bears pointing out that they will continue to be targets of attacks because they are asking, where the money is.


Attackers can easily .nd semantic similar or equivalent APIs from other sources.

the set of Android speci.c APIs, e.g., methods from the android.security.KeyChain or android.nfc.NfcManager classes, are very hard to be replaced.


If we adopt the DO method, the .nal decision should be Deny in the case mentioned in the beginning of this section.

becausewesupport theevaluation of policies in abnormal situations, decisions like PNA, DNA, PD, and PDNA still may appear during policy evaluation and/or decision aggregation even if we adopt some aggregation methods.


In contrast, 23.4% malicious webpages invoked both of the method calls.

in most of the legitimate websites the number of escape method call exceeds than the number of unescape method call (80% benign website).


In our integer programming attack, individual SNP frequencies and pair-wise frequencies are actually such marginals.

existing techniques [58] cannot be directly applied to recover SNPs from them, because of the scale of our problem: up to our knowledge, prior research can only handle as many as 16 attributes [26], while our attack needs to work on 174 attributes.


So we have four possible simulation setups.

figure 4 depicts how f varies across those setups f shows the same trend for all of them -as one expects, it increases with m. the results quantitatively vary across setups.


FordistributinguApps, vendors may choose any channel, including web download.

we assume that the vendor s copy of a uApp is malware-free.


The only prior work we are aware of is [4] where the authors propose a decoding algorithm ala E.-M. or in the spirit of the E.-M.

they do not use any likelihood functions but adaptive scoring Tardos functions, which brings a lot of sub-optimality.


In simulation, the SAS string fed to one randomly chosen victim device (excluding the leader in leader-based methods) was arbitrarily different from the SAS string fed to all other devices.

all devices were given the same correct group size.


This means that Foutputs a forgery (and hence Doutputs 1) with probability at least e-qsqh/q.

if (g,h,y1,y2) is a random tuple then with probability 1 -1/q it is not a Di.e-Hellman tuple.


Fail h5, h1 Figure 5 Each action performed with respect to a single target host is totally ordered and is defined by the particular implementation of the worm.

actions performed across target hosts may or may not be totally ordered.


Note that this result holds only for the plain model, where no trusted setup phase is assumed.

(in the common reference string model, there do exist protocols that remain secure under concurrent general composition [1].)


One property mentioned in this paper, that is, the smoothness, has been investigated in fuzzy control [5].

the distinct feature of smoothness in fuzzy control approaches is that these approaches have to reduce the oscillation before the output reaches its intended value when measuring these properties.


be modeled by SVMs, which are designed for binary classi.cation.

we can use SVMs to make similarly relevant predictions.


The corresponding PDR in both cases, however, is poor because most of the packets are corrupted by the constant jammer, especially when the constant jammer is close to the sender.

the same trend cannot be observed for a deceptive jammer.


We believe that our design is practical, at least for some secure .le-systems scenarios.

a real performance evaluation requires the implementation of this design within a .le system, and is left for future work.


The rate of observed failures can be decreased signi.cantly even with a small (10%) proportion of authorizations cached.

the reduction of the observed performance overhead is the subject of the trade-o.


Intuitively, an access is denied unless there exists a policy which matches the access query.

structured languages allow the speci.cation of composite policies comprising both positive and negative sub-policies to regulate the access to sensitive resources and data.


CONCLUSION We were inspired by the recent work on di.erential privacy of data analysis with continual updates [DPNR10, CSS10a], a research direction motivated by monitoring applications.

our observation is that in monitoring applications typically recent data is more important than distant data.


5.2 Location-Independent Automated Memorability The automated memorability described above depends on a point s location since salience is location-dependent.

we can eliminate this dependence simply by removing the center feature, the only location-dependent feature in the Judd et al.


[20] gave a system where the sensitive information displayed in the public terminal is blurred or redacted, whereas the mobile device displays the content in the subregion around terminal s mouse pointer in clear.

the location of the mouse is sent by the terminal and hence potentially a malicious terminal could send the wrong location without begin detected, and thus compromise message integrity.


For other forms of representation, for example sets of points or sets of lines, it could be possible to map it to a vector in Rn .

such mapping should be key dependent in order to prevent preimage attacks.


Without a running instance, information from the kernel cannot be trusted.

certain .elds are statically known constants or available through commands that depend only on the .lesystem; Figure 5 shows two examples.


Context-sensitive authorization in interaction patterns Vincent Hourdin Jean-Yves Tigli MobileGov and I3S I3S (UNS -CNRS) 930 Route des Colles -BP 145 930 Route des Colles -BP 145 06901 Sophia-Antipolis France 06903 Sophia-Antipolis France ferry@polytech.unice.fr tigli@polytech.unice.fr Stéphane LavirotteGaëtan ReyMichel Riveill I3S (UNS -CNRS) I3S (UNS -CNRS) I3S (UNS -CNRS) 930 Route des Colles -BP 145 930 Route des Colles -BP 145 930 Route des Colles -BP 145 06903 Sophia-Antipolis France 06903 Sophia-Antipolis France 06903 Sophia-Antipolis France stephane.lavirotte@unice.fr rey@polytech.unice.fr riveill@unice.fr ABSTRACT Main requirement of recent computing environments, like mobile and then ubiquitous computing, is to adapt applications to context.

access control generally trust users once they have authenticated, despite the fact that they may reach unauthorized situations.


[30] presented several attacks (e.g., MMIO overlapping) via the PCI/PCIe con.guration space.

the attacks were presented in a different context, and the authors focus was more on the development of a small hypervisor to prevent these device passthrough attacks from causing damage in a compromised OS.


More speci.cally, in Ours, given a CPA secure KEM, we apply the transform described in Section 3.1 and obtain a CCA secure KEM.

in NY, given a CPA secure KEM, we .rst construct a CPA secure PKE by combining with DEM, and then apply the original Naor-Yung transform for the PKE to obtain a CCA secure PKE.


As we can see, P-Pad signcryption provides parallel application of signing fS -1 and encrypting fR, which can result in ef.ciency improvements on parallel machines.

the mini 2 Section 6 easily extends our scheme to support long messages.


By their nature, black-box and gray-box detectors detect anomalous behavior, i.e., behavior di.erent from normal runs, regardless of whether it results from an intrusion or an execution path that was not encountered during training.

white box detectors detect actual deviations from the program text, for which an intrusion is virtually the only conceivable explanation (assuming that the program is not self-modifying).


Thus, most solutions that address the trust evaluation make one of the following assumptions: (i)The trust initialization is not a problem of the model, it is the responsibility of the actor of the system.

this task is not necessarily obvious, especially when it comes to evaluating numerically atrustedthirdparty(eg0.1,0.2, or 0.15).


These works differ from ours in a number of ways, perhaps most notably in that they focus on .nding inconsistencies in static policies.

we analyze policy as it is revealed in accesses over time, which gives rise to our analysis of policy in an incremental fashion, the basis for several of our innovations.


We could still use our decomposition and re-stitching approach to .nd bugs in malware, because the signature veri.cation is a basically a free side-condition that can be ignored.

we could only build a exploit for our modi.ed bot, as other bots will verify the (incorrect) signature in the message and reject it.


If fake email addresses are used, by sending emails to these addresses, an attacker may identify the fake session (e.g., if an immediate delivery failure message is received).

the use of real email addresses would cause obvious privacy exposure (e.g., harvesting of emails).


This is similar to real world situations where a user is asked for different kinds of sensitive personal information to be assured that the user is really who he/she claims to be.

in online transactions with different SP s it is desirable that one can prove the possession of a sensitive information without the actual revelation of this information in clear.


CONDENSED GRAPHS Like classical datallow [1], the Condensed Graphs (C~) model [8, 11] is graph-based and uses the flow of entities on arcs to trigger execution.

condensed Graphs are directed acyclic graphs in which every node contains not only operand ports, but also an operator and a desti-nation port.


As one would expect, ECDSA signs messages faster than RSA.

moore s Law lends a word of caution on those results: they are meant to demonstrate the feasibility of MobiRate but not to hold in the future -in few months time mobile phones will become more powerful, and Mobi-Rate is expected to run seamlessly on them.


While there have been .rst stabs in the direction of improving Web-based password authentication, previous approaches expose at least one of the following problems: Web authentication di.ers from most other authentication scenarios: It exposes many characteristics that resemble properties from security protocols.

it lacks a security protocol s rigorous enforcement of message sequence and integrity, resulting, for instance, in enabling the insertion of messages in authenticated work.ows via Cross-site Request Forgery.


The URL includes 3 arguments, oauth_token, oauth_token_secret, and uid, which the PlainText app uses to communicate with the Dropbox server to complete the account linking.

we found that the linking process can be exploited to launch a serious login CSRF attack, without any malicious app running on the user s device.


Since the length of a token can be different from that of the history token so an SXOR operation, which is shown in Figure !, is performed: transaction token = token (generated by grammar) SXOR history token The XOR of a clear text with a repetitive pattern to generate a ciphertext (encrypted version of the clear te~tt) is usually not recommended in cryptography.

the SXOR operation is not the main cryptographic feature of the proposed algorithm.


Finally, there is one limitation which is di.cult to address: it is possible that MARK simply will not work, due to our limited understanding of FMM revenue models.

it is our .rm belief that injecting unpredictability into the delicate .nancial equilibrium online is likely to have some e.ect on the robustness of the models.


We can not precisely represent the e.ect of caches and pipeline data dependencies.

we can verify absence of side channels for simple architectures (e.g.


[1] and Liu and Ning [2] proposed using deployment information (sensor location information) to improve the resilience to node capture attack.

in practice, the open or hostile deployment environment of sensor networks makes it easier for attackers to locate and selectively capture sensors which can provide more information for attackers to attack the sensor networks.


In [12, 20], researchers try to deploy the network infrastructure with VPN.

these mechanisms still restricted in a machine-to-machine fashion.


The minimum number of distinct draw record types in a single .le is 9.

there are 80 distinct draw record types in the 150 .les.


Similarly, the lightweight software security audit analyzes how the component s software implementation reacts on security test inputs such as maliciously modi.ed network communication or test input generated through fuzz testing.

the monitoring of the component s software is limited to the communication with the device.


Furthermore, credential repositories like MyProxy [4, 5, 25] and SafeBox [1] received much attention in the grid community and are actively used.

credential repositories commonly rely on the security/trustworthiness of a central component.


During damage assessment, if it is determined that a critical link is not updated, then it is clear that data items on one side of the link have not affected items on the other side(s) of the link.

it must be noticed that determination of whether a link is updated adds additional overhead.


Acceleration along the remaining two axes, which are not in.uenced by the gravity must be zero.

acceleration recorded by phonebased accelerometer sensors is not stable over the time.


However, %n-based format-string attacks are the most dangerous, because they allow the attacker to write arbitrary values to arbitrary memory locations (and thus to potentially execute arbitrary code on the victim machine).

format-string attacks based on other speci.ers can only read data, or potentially crash the program (e.g., by following an invalid pointer).


Aspect-Oriented Software Development can be used to address security concerns in software in a modular fashion.

most existing research focuses on the protection of server-side resources.


For our implementation we use a SHA-256 7.2 Secure Messaging Performance hash function, so that both M1 and M2 are 32 bytes.

in this section we analyse the performance of our secure since the shared secret S is also included messaging implementation with both Java Card variants.


For example, if the system is trained for sendmail, then it can not be used for any other process .

we train our system on one set of processes and test it on another set that does not contain any process from the training set.


This typi cally does not hold in practice, in which case we would need to ob .FM .RS 0.02 .JC 0.2 0 0 -0.02 -0.2 0 500 1000 0 500 1000 Noise Index Noise Index (a) Rand (b) Jaccard 0.8 0.8 0.6 0.6 0.4 0.4 0.2 .F1 0.2 tain the name mapping before being able to apply majority voting.

vAMO is agnostic to differences in the terminology that the AVs use to assign malware family names, because VAMO will automatically learn the relationships between different malware family names through the AV Label Graph construction, as discussed in Section 4 and Section 5.


W1 n(b)= H1 n(b)+ D1 n(b) = neH(X0)+ D1 n(b) -s(i) = ne(W (X0) - D(X0||2))+ D1 n(b) (29) To our knowledge at the time of writing, it is not possible to further expand D1 n(b) as for D0 n(b) in (25).

for one encrypted unit D1 n(b)= D(X0||2-s(i)), hence, W1 n(b)= W (X0).


functionality emul[p * ] emulating p * = 0 and the resources com n+1 and crs n+1 .

these n parties have to implement the ideal functionality E. des,em[C ' ], and not Edes[C ' ' .


So in order to build such category-aware reputation, an attacker will primarily copy and submit ratings in one or several categories that are the same with or closely related to the target page s category.

genuine users have no such constraints and they often have broad interests in diverse categories.


Commonly, authentication provided with a key management is recognised as a group authentication, meaning that participating entities can authenticate each other as a group member.

authentication on the level of an individual user is far more complex if relying on the group protocols only.


Authorizationfailures and se curity exceptions account for a large fraction of errors, and they are no easier to handle than other errors [6, 24].

much software simpli.es this problem by treating all errors equally: by either ignoringthemorby haltingexecution[57].server software must correctly deal with the corner cases resulting from errors and authorization failures.


In particular, this also shows o that ((aa)is not a certain answer; hence, query evaluation on a y universal solution (Jin this case) may be a strict superset of the set of certain answers (which is the empty set for this example).

n(m2J)coincides with the set of certain answers.


The intuition may lead to duplicate A elements in order to integrate them at the same time in B s and C s siblings.

the presence of the same A element(s) in both sets may allow some inference regarding the relationship between B and C elements.


A Multi-layer Tree Model for Enterprise Vulnerability Management Bin Wu Southern Polytechnic State University Marietta, GA, USA bwu@spsu.edu ABSTRACT Conducting enterprise-wide vulnerability assessment (VA) on a regular basis plays an important role in assessing an enterprise s information system security status.

an enterprise network is usually very complex, divided into different types of zones, and consisting of hundreds of hosts in the networks.


As the architectural reasons for this second Trace-cache BTB are out of interest for this paper, we refer the interested readers to citeShen,TraceCache.

more interesting is the information on their sizes, and especially their joint functionality which we can partially learn from [34, pp.


Medical data collected by these devices must be secured, especially on the wireless link to the gateway equipment.

it is di.cult to manage the required cryptographic keys, as users may lack the awareness or requisite skills for this task.


Earlier, in a single Assertion-usage or single-AP model, the AP was guaranteed that all the services by the members of the CoT, were completely based on its Assertion of the User.

in this extended scenario, this AP is not in a position to gauge how much of the decision for providing a service at a RP, was based on its Assertion and how much based on Assertions from other APs.


Alternative schemes to measure throughput: Our current attacks measure throughput by simply forwarding TCP tra.c through the Tor relays.

much work has been done in the networking community in the area of throughputprobing,andit maybepossibletoleveragethese techniques for improved performance.


The existing IC metering approaches can detect intellectual property (IP) violations in IC manufacturing.

no exact quanti.cation of the number of chips that have been produced illegally was proposed, beyond the collision probabilities that were computed by variations of the Birthday paradox.


That is, a bot could record a human play of the game and then simply replay the recording.

the game environment especially in MMOGs is highly dynamic.


This is a strong indication of the relevance and e.ectiveness of context in phishing attacks.

the study also showed that 15% of the users in a control group entered valid credentials on the site they were pointed to by an unknown (and .ctitious) person within the same domain as themselves.


To address such shortcoming, Identity-Based Public Key Cryptosystems (IB-PKC) were introduced.

such cryptosystems su.er from the key escrow problem as the key generation server learns the private keys of all users.


Moreover, CarRental.com may query user s .ight schedule (or other attributes) from Airline.com.

using any conventional communication over network (e.g.


By keeping track of a thread s stack boundaries both in the kernel and the userland3, PVE component can identify the thread that is running by referring to the ESP register at any given point.

if it encounters a value in the ESP register that does not belong to any of the known threads, it is possible that a new thread has started or that a thread s stack frame has grown.


In addition, these techniques are generally byte-level and do not take into account type information of the program.

lazyTainter is designed for a managed runtime of an object-oriented language.


The third, and last obstacle is that the Linux dynamic linker ld.so is randomized in PaX via changing the mmap base.

the Android linker is much simpler and must exist at a prede.ned address in memory, .xed at build time.


Responding to their request, we kept our work confidential to allow them time to fix the vulnerabilities.

while the crowding characters together method, if implemented properly, appears to provide better security, it can introduce a usability shortcoming that has been long ignored, namely a new type of confusing characters.


One tool for doing this is known as BAN Logic [2].

applying such formal analysis to device authentication protocols in mobile computing applications has not been studied to date.


On the other hand, if the attack is run over AC power, the only issue is being able to route that much data in a timely fashion.

the tra.ce routing issue should be much less of a problem if speci.c hosts are targeted.


In theory, one could purchase enough computational resources to serve attackers and good clients.

anecdotal evidence suggests that while sites provision additional link capacity during attacks [33], even the largest Web sites try to conserve computation by detecting and denying access to bots [30, 42] using the methods in the next category.


Also they prove that in the worst case, greedy from Section 4 does no better T(n) of the optimal solution.

this approximation ratio assumes that all nodes are zero-injection.


Unfortunately, it is not possible to change the thread group of a running thread.

we can handle this method in a proxy which starts a new thread in web application instance/session speci.c thread group and starts running the original service in the new thread.


database on web applications from the attackers.

if the web application can not detect the inputted attack sequences appropriately, attackers have possibilities to juggle the database of web application through the form on the web page.


Many security countermeasures (e.g., patching, automatic signature generation for intrusion detection systems) require vulnerability information to function correctly.

despite many years of research, automatically identifying unknown software vulnerabilities still remains an open problem.


The user is informed about the decision, but not asked to intervene in any way.

the system gives the user the ability to carry out this action through another interface.


In the sequel, we focus on the privacy expiration window model that imposes a sharp threshold on how privacy degrades.

smoother expiration models are possible.


To defend against this, iptables turns off kernel pre-emption and interrupts.

we noticed that disabling interrupts on each resource request, perhaps several times per system call, has a noticeable impact on system interactivity.


between accuracy and sensitivity in network anomaly detection.


Clearly, executing the Traust resource access protocol takes longer than using a more traditional means of acquiring resource access tokens (e.g., obtaining a Kerberos ticket).

this comparison means very little, as traditional access control systems cannot be used in open systems environments since the identities of authorized users may not be known a priori, requiring users to resort to out-of-band methods to gain access (e.g., sending written requests to resource providers).


We work around this by authorizing our users to generate an application-speci.c password for those type of apps.

this is far from ideal since those passwords can be phished.


The most obvious kinds of data that can be retrieved from a phone are call logs, contact lists, and text messages.

in an investigation, other features of a modern mobile phone, such as ring tones, T9 dictionaries, canned responses, video files, image files, calendar events, miscellaneous documents and data files, and location information can also provide valuable clues.


If an ISP o.ered another policy, say B+ , low risk users would strictly prefer it.

the high risk users would also prefer this policy, bringing us to the scenario from Sect.


If we want secure communications, information of DATA field must be encrypted.

wang-Juang-Lei s scheme does not encrypt as following fig 1.


On the one hand, dedicated TEEs like SIM cards provide easy migration, as they can be moved to the new device.

secure and practical realization of device migration for system-wide TEEs like ARM TrustZone is harder to implement.


A feasible solution is to frequently exchange the secret using public key cryptography, which each time uses a new randomly generated publicprivate key pair [13, 15].

considering the increasing number of smart gird devices, it would be costly to deploy the PKI infrastructure.


As for Android, we discovered that many mobile service providers were not directly invoking their relying party applications (e.g., using Intents), but rather sending data through the return values of their own applications (e.g., when invoked by a relying party).

when passing data through return values, additional checks are needed to verify that the caller application matches with the intended recipient of the data.


A wide range of commercial programs exists for the task of detecting malicious binary .les.

malware detectors are unreliable especially when detecting new malware or new variations of existing malware [8].


Determining a Parallel Session Attack on a Key Distribution Protocol using a Model Checker Vladimir Pa¸sca Data Communications Security Laboratory, University of Limerick, Limerick, Ireland vladimir.pasca@ul.ie Anca Jurcu¸t Data Communications Security Laboratory, University of Limerick, Limerick, Ireland anca.jurcut@ul.ie  ABSTRACT The use of security protocols to protect sensitive information is critical.

.aws in the design of security protocols can make them ine.ective.


However, in cases where physical access is not granted to the adversary, the security properties of a hypervisor and hardware are equivalent.

a hypervisor offers signi.cant advantages over hardware for implementing low-level security.


Much like TMI, any invariants that are violated result in a transaction abort.

this framework does not allow security checks at each access to a security-relevant resource, or the maintenance of introspection logs.


[12] show a survey on malware detection techniques, while [11] gives an overview on automated dynamic malware analysis.

both papers don t deal with bootkits in particular.


SynchroTrap s design is based on a similar insight that malicious accounts tend to act together.

copyCatch assumes that a user can perform a malicious action only once (e.g., like a page at most once) and models the detection problem as a co-clustering problem [31].


Current solutions to defend WSNs against such cheap jammers(e.g.,channelsur.ng[2], randomizedSFDs[1]) are all based on hiding an ongoing packet transmission from reactivejammers that onlyjam when theythink orknow there is an active data transmission.

these solutions require tight syncrhonization between each sender-receiver pair to ensure successful data delivery.


This means that they did not spoof their source email addresses and registered SPF records to mimic a legitimate sender.

the non-MPE spam messages discussed in Section 3.2.1 did not contain such "Pass" messages.


Obviously, many such applications are intended to operate on users private information.

recent studies [18, 16] show that smartphones operating systems still do not provide clear visibility of how third-party applications use the owner s private data stored on the smartphone.


In §5.3, we examine the addition of annotations extra group or role information that accompanies accesses into the prediction engine to recover some of the bene.t, but we .nd this offers only incremental improvement.

we show in §5.4 that by moving to an ED con.guration, where the prediction engine can leverage all information deducible from past accesses, bene.t can be more substantially increased (though still not to the levels promised by an ND evaluation).


If not, and if s has a suffix state, the suffix state defines the following state.


The paradigm is particularly useful for several reasons: many national demographics are having increasing number of aged people; health providers are facing shortages of health workers; costs of healthcare are skyrocketing; and incidences of medical errors are at all-time high [25].

as desirable as Scenario-B seems, several things could go wrong when we consider several aspects Figure 2: A Desirable Emergency Response Scenario of security and privacy of electronic health records (EHRs), some of which are highlighted in what follows.


An authentication theorem such as QB in Section 2.2 states an implication: if a regular participant chooses uniquely originating nonces, then itspeer hasengaged in a matching strand.

two regular principals could choose the same nonce.


PiOS generates an application s control-.ow graph by backtracking all Objective-C calls and by reconstructing the class inheritance relationships.

piOS suffers from some shortcomings: First, its analysis does not cover embedded metaclasses (i.e., root classes of Objective-C classes), which frequently occur in iOS applications.


If isAvblE ntC hat(user) is false, RETE will return that R3 will never .re, thus avoiding sensing of the high cost location predicate.

we will have to sense isI nW orkGroup(user) to evaluate R4, which is a lower cost predicate compated to isInO.ce.


The system is run by the market places or a third party to prove or disprove security properties of apps.

they rely on a single party to perform the entire process including tracking sensitive information .ow, identifying security and privacy risks, and reporting potential risks of information misuse.


In the SMS trace we collected, during days when infection has not taken place, we do no observe any instance that Ptoday exceeds the detection threshold.

on the day (day 13) when the virus is injected, Ptoday count quickly rises above the threshold, resulting in the proxy moving onto the alert phase.


to be very close to half-integers, we would need high precision to ensure correct rounding.

after Tweak 1, we have the following lemma: Lemma 2.


The SMI handler is also not responsible for managing the communication between running workloads.

microhypervisors reside at the system s highest privileged level.


All values are statistically signi.cant with p<.001 the platform owners (i) to avoid granting the full privileges to third party apps, and (ii) to possibly recognize apps with anomalous permission request patterns for triaging the manual review process.

as it is with other security problems, the permission systems will not be e.ective if users do not comprehend how they work, or if the permission systems contradict other signals the users receive.


100 and 5 respectively), the optimal scheme will be Product using RSA instead.

as we noted above in our analysis of RSA based schemes alone, in this region all three of MMM, Product, and Iterated Sum have nearly identical performance, so Iterated Sum is the wiser choice in case predictions of * R1 and R 2 are wrong.


These solutions can be categorized in compiler-based solutions [19, 59, 15, 40, 48]; instrumentation-based solutions [37, 16, 1, 2, 29, 55]; and hardware-facilitated solutions [26, 25].

as we discuss in detail in related work (Section 6), the existing solutions su.er from various shortcomings and practical de.ciencies: They either cannot provide complete detection of ROP attacks [16, 29, 37], or require side information such as debugging information [1, 2] or source code [19, 59, 15, 40, 48], which are rarely provided in practice.


Since the traces are generated from the same model that the classi.er uses, this is obviously an arti.cial experiment that overestimates the success rate of our attack.

the IMDB model underestimates the success rate due to the arti.cial transition probabilities described above, so, together, these two experiments provide rough bounds on the performance of our attack.


They track the time evolution of the RSSI and observe that the pattern of the sampled energy reports can be useful to separate information signal from jamming.

they conclude that these metrics alone are not able to detect every type of RF jamming and propose the combined analysis of di.erent metrics (e.g., geographic position, medium access delay, PDR and RSSI).


A high security level might bringg about many alerts, most of which will be false alarms, but the ere will be almost no missed detections.

a lo ow security level will lower the false-alarm rate, but will cause the e system to miss some attacks.


Specially, we believe that there exist certain correlated features and if they worked together, then attackers might be able to uniquely identify a speci.c person.

this set of correlated features can not be directly acquired.


Because our approach does not attempt to recover the original instructions, but rather attempts to capture the relevant behavior of the code, it will not match those results for accuracy.

our approach is more general, and can be applied to a wider range of obfuscation techniques.Thus,it shouldbeseenascomplementing existing approachesbyprovidinginformation when others cannot.


As described above, Langweg and Snekkenes assign attacks a third property, the cause.

causes are speci.c to the implementation of a CI system and therefore, the analysis in this section looks at causes only as far as they are relevant for CI systems in general.


In addition to the Bayesian calculation schema, the security ontology is used to enrich the Bayesian network with concrete information security domain knowledge.

the high dependence on realistic input values (attacker pro.le, control implementation e.ectiveness, and a priori threat probabilities) requires further research on sound methods and techniques to gather, store, and provide these crucial threat probability calculation components.


These options may provide better performance in terms of actual time spent performing certain administrative tasks.

there are disadvantages to this approach, some of which become signi.cantly more important to address when considering an attack in progress.


(¬Y :revoke(X)@rev) In the original speci.cation S3, errors are not propagated through delegation chains.

the speci.cation S5 propagates errors through delegation chains and thus denies access to subjects who are not direct delegates and do not have a non-revoked chain.


The current developer version still allows an observer to capture the information displayed by looking at the device from the front.

this issue can easily be .xed by making the display non-transparent, since it only occludes a small part of the user s .eld of view.


For pages that allow the use of plug-in code, wikilaunch launches wiki.py with I = {iv} to allow v s plug-in code to participate in the page s rendering.

the plug-in relies on FlumeWiki code during processing, which it cannot read off the disk: FlumeWiki s code does not have iv in its integrity label.


And, there are some detection techniques parsing of the attack strings [7].

it is a problem that the parsing techniques are often tend to be complicated.


ROS(A)is stable under attack A, the compromised consumers may still experience monetary losses and the system may run at low e.ciency.

this paper focuses on the impact of attacks on the system stability, which is a fundamental system requirement.


The trustworthiness associated with public keys is similar to PGP [16].

whilst in PGP the trustworthiness associated with a key determines to what extent the user is trusted to act as 'introducer' (i.e., for authentication); in this paper, the trustworthiness associated with the key determines to what extent the user is trusted to sign assertions.


1.2 Hybrid Security and our Contribution Conventional, non-hybrid MPC protocols distinguish only between adversarial settings in which they provide all speci.ed security guarantees, and settings in which they provide no security guarantees at all.

mPC protocols CO security: Up to a .rst threshold tp, the security is IT.


Our role based collaboration model supports context sensitive and condition dependent access rights.

the collaboration designer can easily make mistakes when specifying such policies, e.g., a precondition may be incomplete or role admission constraints may be con.icting.


This reduces the revenue of the Botmaster, but the Ad Consortium is still happy as their costs are also lowered.

what happens if the number of impressions goes up?


RELATED WORK Imperfections of the human visual and auditory system have been used as the basis for hiding data in still images, audio, and video [Bor96].

watermarking IP where no errors are allowed, such as designs and programs, require different techniques.


As a concrete example, the browser may be rendering a page that uses asynchronous requests to periodically update a component of the page with some real-time news feed.

these asynchronous requests are of little interest for the purpose of mining subsequent user-browser interactions, and therefore we would like to .nd a way to determine whether the user had in fact moved on to request another page, rather than waiting inde.nitely on a page that periodically updates its content.


Each retailer is reluctant to provide its own historical data.

it may bene.t the whole supply chain, if the retailers together can collaboratively provide a forecast on customer demands to the supplier.


Hence e = e ',¢::.~ wl = w2mod q ¢~:, [(u. q + al) .v q/p+ (u q + al) bt/pJ = L(u q + al) bl/ pJ mod q In general, (u q + at) " v "q = a (b - (b mod q)) > p. Ifp I (u .q + at) v, wl = w2 mod q.

it is impossible, since (u q + al) <pandv<p.


The language provides an operational approach based on a rich and expressive library of assertions to support event logging, correctness checks of the user actions, and history tracking for the relevant events occurred in the federation.

aBPL lacks to support for speci.cation of privacy policies and protection of resources via enforcement of these policies within the federation.


2.3 Adversary Model We consider an adversary who intends to acquire sensitive user information and has a full control of the public cloud.

we assume that the private cloud is trustworthy: speci.cally, the adversary has no access to the nodes on the cloud and its underlying network, and therefore cannot launch such attacks as eavesdropping.


RTS, CTS, ACK...[2] this key to each mobile terminal one-by-one through unicast, the overhead increases as the number of mobile terminals increases.

since SAP v2 distributes the temporary handoff key to each mobile terminal using broadcast, the overhead is minimized.


Supporting a disk drive emulation is straightforward based on the technique used to implement the network interface emulation.

the main question is how to secure the disk access from a compromised legacy host.


Both phases can be run on a computer since the keys are distributed out-of-band.

we have considered running both phases on a smartphone (with the speci.cations described above), should these need to occur in the .eld.


In an Escudo-enabled browser, Set-CookieSub is equivalent to Set-Cookie.

in a non-Escudo browser, the Set-CookieSub header will be ignored, so no subsession ID will be set as cookies on the browser side; therefore, requests from a non-Escudo browser will not attach any subsession ID.


Interoperability helps in bridging the gap between government to citizens, government to government, business to business and business to consumers.

interoperability does not come easy as it opens the way for several security and privacy breaches.


2.4 Attribution Systems There has been a major research e.ort over the last several years to design and implement feasible network tra.c traceback systems, which identify the machines that directly generated certain malicious tra.c and the network path this tra.c subsequently followed.

these approaches restrict the queries to network .oods, connection chains, or the entire payload of a single packet in the best case.


If the attacker is able to scan the network and see that a particular address was veri.ed, the attacker can then send spoofed packets for that address since not every UDP packet can be veri.ed.

the number of legitimate users currently authenticated is much smaller than the usual IPrange usedbyspoo.ng DoS attacks and the attackermust be able to see that a particular address has been authenticated, thus TrueIP seriously reduces the e.ectiveness of the DoS attack.


in [42] developed new tools to reverse engineer network message formats by observing how a program processes network messages.

the formats reverse engineered by previous tools have missed important information that is critical for security applications.


4.4.1 Rotating and shifting Instructions on ARM that use the arithmetic addressing mode, explained in Section 2.2.2, can perform all kinds of shifts and rotations on the last operand prior to using it in a calculation.

not all variants can be used in alphanumeric instructions.


One worry of eagerly sandboxing before the loop is it might change the program behavior.

if we assume good code will always have pointers that point into the data region, then eager sandboxing should be an idempotent operation for good code and it breaks only programs that would violate the policy.4  4Certain programming practices use pointers that are out  (3) A range analysis is then performed to decide if any check is unnecessary.


If successful, she will only gain a site-speci.c password, which cannot be directly used to attack the user s password for a second site.

with this site-speci.c password she can then become the second type of attacker.


This framework is implemented using JAVA-MIDP and provides basic communication primitives between devices as well as automated logging and timing functionality.

we had to amend it to accommodate unlimited number of devices and change the inter-device communication channel from Bluetooth to Wi-Fi.


We managed to observe the heat trace for 3 seconds after the pattern was drawn.

we were unable to extract the pattern from a recently used device.


Based on our observations in Section 4, we conclude that only completely identical ROs, with identical hard macros, are allowed to be used for comparison in order to avoid foreseeable comparison results.

it might be necessary to use two RO types as shown in the hard macro of Figure 2, because of design speci.c area constraints.


Therefore, user requirement should be introduced into multimedia authentication.


One way to o.oad the detection engine is to select a subset of the monitored tra.c to be excluded from the NIDS processing using a capture .lter during initialization [12].

events of excessive tra.c load or bursty tra.c can still occur.


This means that two dynamically mutual exclusive roles may be assigned to the same sub ject.

the subject is only allowed to activate at most one of its dynamically mutual exclusive roles (permissions) at the same time.


This prevents payload code from executing.

scheduling of multi-process or multi-threaded applications, asynchronous signal delivery, time, random numbers, .le and process identi.ers are major sources of inconsistency among the variants.


For example, Northrop Grumman's Corporate Security Council has authority over everything pertaining to information security from buyer contingency planning to investigation issues [4].

once the Security Council approves an initiative, it still requires further approval from the CIO before corporate-wide implementation.


Someone may argue that in current road sys tem, a vehicle can already be traced by means of its license plate number.

most parts of VANET are auto matic (e.g.


Figure 2 can be used to show that the Logistic map is also chaotic by geometry of the iterated map and restricted to {0, 1} value at r = 1.

further investigation provides that map has indeed, a period-2 cycle for r slightly greater than three, equivalently, or fixed point is depicted in this figure.


The signature above is meant to authenticate the client as well as to protect the message identi.er and body against tampering by an active adversary.

there is an XML rewriting attack where an adversary can prevent the message identi.er from being Figure 1: WSE Policy Advisor processed or cached at the server.


Their model can specify conditions, purposes, obligations, etc., which are necessary for privacy policy speci.cation.

it is not apparent whether HIPAA can be encoded in their language due to absence of examples of such encodings.


In [28], some primitive concepts that relate to the authorization of joint actions are discussed and are of relevance to the notion of cooperative action that we have considered.

the work in [28] is based on a different view of collective action than the one that we adopt and, unlike action control, there is no discussion of any formal aspects of joint action, no formal security model is proposed, and no details of any implemented system are provided.


Some of the processes that receive taint early (like the Xorg X server, or the screensaver), conceivably should have access to the tainted bytes.

after some time taint again spreads to completely unrelated user processes (e.g., tar, nautilus, hald, python, apt-get, etc.


In all test cases, however, CLAMP omitted the time to fork a new virtual machine and assumed that virtual machines are pre-forked, which makes their performance numbers appear signi.cantly better than they might be in practice, when new sessions would require forking new virtual machines.

silverLine s end-to-end performance measurements also include time taken to spawn a new process that serves that client.


We can use VMI tools to simplify this complex system, and obtain the entire state of a VM from the safer outside, namely the Dom0 or host for virtual systems running on Xen or KVM, respectively.

many companies pay for public cloud services to store their data and run computational applications, because of the ease of con.guration and maintenance.


For example, when a user located in Santa Barbara plans to  Figure 1: HengHa Detection System Architecture go to Chicago for business, the majority of the searches she does on a trip planning web site will be about Chicago, the .ight from Santa Barbara to Chicago, the hotels and car rentals in Chicago, etc.

data harvesting attackers input different binding values on the search form and change predicate values much more frequently in their sessions.


The WS-* family of security schemes [1] aims to provide a security framework that addresses all the security issues around web services.

this strong security framework is built on weak foundations: McIntosh and Austel [13, 12] have shown that the content of a SOAP message protected by an XML Signature as speci.ed in WS-Security can be altered without invalidating the signature.


Digital signatures [7] guarantee the integrity and authenticity of digital documents.

the signer may hope the recipient of a signature would not be able to show its validity to other parties.


On the one hand, we want to identify which types of attacks can be best detected using our approach, and we want to examine the quality of the detection performance of our active probing technique.

we want to analyze the impact on the network traf.c when employing our active-probing IDS.


While the letters appear very distinct to the human eye, when represented on the RGB spectrum they are so close that it is almost impossible to use the CFS [32] or the Anti-pattern techniques on it.

as visible in .gure 6, an effective way to counter this defense is to have the breaker work on a different color representation that is closer to the human perception, namely the HSV or HSL [29] ones, and binarize the captcha by using a threshold based on the hue or the saturation.


(.p (nh)=black..p (nk)=black) then .p (nh,nk)=black else if .pi (nh,nk)=white..pj (nh,nk)=white then .p (nh,nk)=white return(p) Figure 7: Composition of two permissions As an example, with reference to the authorizations in Figure 5 and query q2 in Figure 6, the set of authorizations applicable includes p1 and p4.


Some MAC protocols, such as B-MAC [6], use adaptive thresholding for carrier sensing to identify the best parameters for wireless sensor network s application at compile time or run time and thus provide some level of immunity against some certain types of constant jamming attacks.

these protocols do not in general provide resistance to a broad range of jamming attacks.


This approach is e.ective to prevent kernel rootkits that introduce their own code.

advanced rootkits operate without explicitly injecting malicious code by using techniques such as kernel memory devices, kernel bugs, or return-oriented programming; and this approach cannot handle such cases.


The Aj,0 additionally lowers the matching score even more, so that the child finally is rejected, anyway.

this can also decrease the comfort because persons of level 2 could also be rejected this way.


Some of them rely on eXtensible Access Control Markup Language (XACML) policies [6, 7] to specify the access restrictions on the data offered by the peers for hierarchical P2P networks.

none of these solutions considers existing access control components and collaborative applications residing on the peers.


Two users will only be able to establish a relationship in the social network if they know of, or are introduced to, each other.

in an encounter-based social network the only requirement for establishing a connection is that you are in the same place at the same time as someone.


Firstly, as just described, important system programs can be cryptographically protected to prevent privileged malicious processes from modifying these to leak decryption keys.

even if the attacker has the ability to bypass the security kernel s controls and write directly to the storage device itself, this will cause the MAC value stored in GPRIV to not match that which will be calculated when the program is next accessed.


One approach for obtaining representative data is to increase the number and size of unused address blocks [11].

without understanding how the placement of the monitoring blocks relates to the traf.c observed, there is no way to know if that sample is representative.


For example, we could consider that a timing attack against the location privacy is not feasible and thus we could allow anonymous or opportunistic connections.

the more we introduce alternatives for the privacy settings, the more di.cult it is for the user to make good decisions about the desired privacy levels.


This variable is used by the Android Debug Bridge Daemon (ADBD) to determine whether developer can login as root.

attackers cannot embed this exploit into applications because Android applications cannot access ADBD.


By analyzing all of our 250 downloaded .rmwares, we discovered that most of .rmwares can defend against native level vulnerabilities.

nearly 99% .rmwares have Java level vulnerabilities.


A device-centric approach may employ a speci.c behaviorbased classi.er for implicit authentication.

a classi.er may not be suitable for a particular type of application.


The usage of quieter keyboards, as suggested by [1] may also reduce vulnerability.

the two so-called quiet keyboards we use in our experiments prove ineffective against the attack.


Although criminal accounts could obtain followers by randomly following any account and expecting it to follow back, this method is still not very e.ective, due to the low chance of successfully alluring legitimate accounts to follow back.

through following criminal accounts, hubs can automatically acquire those criminal accounts followers information (Username or Account ID).


Opportunistic networks can be used to exchange information in a wide range of domains from social media to military applications.

such networks also present serious privacy and security issues, particularly the need for an approach to exchange content and interests that neither (i) compromises the privacy of subscribers nor (ii) provides unauthorised access to untrusted brokers.


Also, Bob knows that the message has not been modi.ed since Alice generated it, since otherwise the MACs would not match.

a MAC can t provide non-repudiation: Eve can t look at the MAC d message and determine that Alice sent it, because Eve doesn t know the MAC key.


REVERSE-ENGINEERING DESIGN SE-CURITY SCHEME For a side-channel analysis, all details of the bitstream encryption scheme are required.

this information cannot be found in the public documents published by Altera.


Unlikethepreviousprotocols, this protocol will be executed repeatedly.

there are only 2m subsets of P(C1 ,...,Cm).


In many situations we have furthermore not even de.ned or agreed on the security attributes to measure on [8].

when we actually have de.ned and agreed on such attributes, like in the common criteria [2], the measures are often qualitative, i.e., based on experience, and do not carry enough information about its values to allow formal analysis.


Although the manufacturer s Web site proved no help in identifying security software, a Google search of the Web site discovered an ImageRUNNER Security Toolkit available via a request form or a downloadable document (www.usa.canon.com/cpr/pdf/Brochures/SecurityKit.pdf).

this document is product sales literature.


The need to distribute and manage only a restricted number of certificates is good from a security point of view.

the limited certificates each sensor or tag owns restrict their capability in authenticating and communicating with a large number of nodes.


1 Introduction EPAL [4] or E-P3P [17] can help organizations enforce their privacy policies.

it is still the responsibility of organizations to .nd and respect the applicable policies [5].


As described in section 3.2, flow cache and reassembling buffer are not essential for unanchored signatures.

to support matching for multiple flows, matching state switching must be considered.


Instead, an e.ective defending strategy should be adaptive, i.e., it should be able to learn the attacker s strategy and dynamically compute the best response strategy to counter the attacking strategy.

assuming that the attacker may change its strategy arbitrarily is neither useful nor practical.


Note that triggers allow GTRBAC events and status conditions only [12, 13].

it can easily be extended to include other events and conditions.


2 We anticipated that the test suite would not be complete, due to new functionality that needed to be tested and due to functionality that is intrinsically hard to test (such as, for example, key migration).

we expected that for the straightforwardly testable and previously tested TPM functionality, the suite would provide us a push-button ability to tell us that our TPM driver and TSS were functioning correctly, and would thus enable us to test the more sophisticated features and scenarios.


At the beginning, the connectivity coding drives the geometry coding.

since the geometry data occupy most of the storage space in a model file, the connectivity-centric algorithms restrict the efficiency of geometry compression.


For example, to express hierarchical rolebased access-control (RBAC) [14] in XACML requires a fairly cumbersome encoding [1].

its more direct request evaluation strategy suggests that policies written in XACML are more transparent than policies written in languages based on .rst-order logic (as we motivate in Section 2).


An HLB might monitor server health via echo requests and route only to responsive servers based on (for example) average response time, fewest connections, or hard-co ded weights representing hardware capacity.

hLBs are not as scalable and as a result are often used in combination with RRDNS for extremely high volume sites.


Within our test range, the runtime varies from a few seconds up to a few hours, which seems well suited, e. g., for a distributed privacy-preserving scheduling application or an electronic voting system.

with a large number of inputs k, e. g. k = 100, the protocols are not suitable for real-time applications or applications in which the result of the reconciliation is instantly needed.


3.2 Our Generic Construction Katz, Sahai and Waters [2] proposed a generic vector transformation to support polynomial equations, which is also suitable for our EDE construction.

the construction is not very e.cient due to the long vector transformation.


The number of certi.cate authorities is very small and the information they have is highly classi.ed.

the number of arbitrators can be huge (e.g., each peer can act as an arbitrator) and the information given to the arbitrator is limited.


collected 204,040 applications from various online stores and reported native code deployment rate of 4.52% in total [31].

the ma jority of the applications may not be installed and used by most smartphone users: according to statistics shown in Google Play in November 2013, the No.1 application in the chart has accumulated almost a billion installs, while the application ranking 300 shows less than 500,000 installs in total, which is approximately only 0.05% of the top application.


The inpainted region may show a distinct pattern that helps locate the inpainted region.

these patterns can be destroyed by scaling the image s size with a nonlinear bicubic interpolation and by adding noise to the image.


The free response question has the advantage of not prompting the user with any ideas that may not have occurred to them otherwise.

pilots showed that answers to free response questions were frequently too vague to be useful and that respondents may not have put enough thought into their answers.


An added complication with security regimes that are overly strict, is that such unregulated activities can become the means of getting things done in the system.

the di.culty is that these side-activities often lead to the compromise of security in a system.


A more general approach, called generic decryption, has been to emulate execution while the shellcode decrypts itself (typically using a heuristic to guess when this process terminates).

the overhead of this technique can be substantial and there are a variety of counter-measures that undermine its ef.cacy [27].


for the 8-point integer DCT we employed in our scheme, we cannot estimate the watermarking error directly similar to the processing for the floating-point DCT because the 8-point integer DCT is not a linear transform and therefore the distortion caused by the addition of the maximum coefficient ACmax cannot be calculated using eq.(7).