4.1 Ethical Considerations Our experiments randomly forge an address book and collect corresponding user pro.les from messenger applications, which may bring about ethical and legal issues, similar with the cases in [9, 3].

this is the most e.cient and e.ective way to conduct our experiments since 1) other methods like survey always su.er from in.ating user concerns about privacy [6], by directly asking questions about privacy; 2) Comparatively, empirical experiments are more reliable.


2.2 OAuth 2.0 OAuth 1.0 (and OAuth 1.0a) had several notable limitations for its usage scenarios.

instead of augmenting the existing protocol, the working group decided to alter the speci.cation completely to create a di.erent protocol OAuth 2.0.


DISCUSSION AND CONCLUSION Someone who has stolen a password .le can brute-force to search for passwords, even if honeywords are used.

the big di.erence when honeywords are used is that a successful brute-force password break does not give the adversary con.dence that he can log in successfully without detection.


These semantics appear to be closest to those de.ned in GTRBAC and the model of Ray and Toahchoodee.

we would argue that RBAC- has the least intuitive semantics: why is ST it appropriate to ignore the enabling conditions on intermediate roles?


Since they only support string operations, they are not able to handle non-string constraints, and particularly length constraints that are related to both string and non-string domain and cannot be captured in each individual one.

the solvers Kaluza [28], [6] and Z3-str [39] are in the same category as ours, and can reason about strings and non-strings simultaneously.


At present, there is no limit to the number of times a host can make a TPM use an encrypted key or data blob once it has a copy of that blob.

if we can enable a TPM to keep track of a large number of virtual monotonic counters, then we can link a blob with a particular virtual monotonic counter so that the TPM can use this counter to track and limit the usage of these blobs.


In DAC, any user can arbitrarily grant access to objects the user creates, but such policies are not enforced against privileged users.

sELinux provides mandatory access control (MAC).


A broker will forward encrypted content to a subscriber if and only if (i) the root node of the policy is marked as satis.ed and (ii) the interests match the tags.

this scheme targets both the access control problem (C1) and the .ooding problem (C4).it still has some privacy issues.


matthew W. Pagano Johns Hopkins University Baltimore, MD USA mpagano@cs.jhu.edu  there are many security disadvantages to this system that allow adversaries to steal user credentials.


A Use License that is attached to the document also contains the content key (encrypted with the public key of the client).

the client s private key is protected by the lockbox and thus extraction is not feasibly possible.


We .rst describe the signed hash chain scheme, which incurs very little overhead of computing and requires nodes to perform only one public key operation.

this approach does not tolerate packets arriving out of order, as would be the case due to collisions in typical wireless networks.


The impact of attacks against single HLRs is lessened assuming that the other HLR can support the additional load [48].

such a defense is unlikely to cluded in the Appendix.


The physical distance between two countries in a geographic map does not necessarily correspond to the level of connectivity between the countries.

in IMap, country size is proportional to the importance of the respective ASes in the AS topology.


Each could still be used to satisfy governmental reporting requirements since the government, as the issuing CA, would have full access to the underlying identifier.

the two VCs could not be used to link her medical and employment records.


ClickIDS is more precise in identifying attacks based on overlapping elements.

unlike NoScript, it is not able to detect attacks based on partially obstructed pages.


It is the worst situation when the target program depends on all the programs in a system.

in a multi-task operating system, when independent applications run simultaneously, a target program usually depends on only a part of the system.


If the event is managed, and has a list of attendees, it is possible to bootstrap the EnCore event similar to PIKE [22], using Facebook or another existing registration system.

unlike PIKE, EnCore can also handle ad hoc events.


Obviously, b should be chosen greater than 0 to give honest nodes an incentive to revoke.

to prevent a malicious node from abusing our revocation scheme to increase their overall position by revoking other malicious nodes, we place an upper-bound of 1for b.


Again, we feel that it is impossible both for the user as well as the system to make clear-cut distinctions between good users and bad users.

the less abstract distinctions between wireless and wired, or using VPN and not using VPN are concepts that are more readily understood by users.


Although such rootkits are disabled when the operating system is rebooted, they can still retain long-term controlover server-class machines, which are rarely rebooted.

this technique is not as effective on smart phones, because phones are powered off more often (or may die because the battery runs out of charge).


Spaces must be monitored from a multitude of perspectives, each of which will generate a vast quantity of disparate information, including structured, semi-structured and unstructured data.

existing security toolsets and offerings are not yet well equipped to analyze these kinds of data with the necessary speed and agility.


In these approaches the watermark is embedded into the whole image.

this can typically be vulnerable against cropping and local geometric attacks.


So long as the information .ow requirements align with this policy MAC is a reasonable approach to secure information sharing.

we can state empirically that this alignment has not turned out to be very common over the past three and a half decades of experience.


We attempted to use the observed probe rate of a host as a way of identifying NAT IP addresses.

the wide variation in machine load and network connection speed of individually infected IP addresses masks all but the most blatant evidence of NAT use.


In our multi-cloud ORAM, we can still achieve about 2X3X client-cloud bandwidth cost even with a single partition.

with a single partition, reads would have to block waiting for reshu.ing operations of up to N blocks to .nish (e.g., gigabytes or terabytes of data transfered between the two clouds), resulting in prolonged response times.


Recall also that campaigns 19 and 26 are synchronized in lifetime (see Figure 6), we can conclude that they are di.erent spam campaigns in contents, but they share the same infrastructure to deliver spams.

the IP overlap between campaigns 22 and 32 is almost zero though they are temporally correlated.


Combining these ideas, we can extend the foundations provided by The Open Group into a complete quantitative security risk management paradigm.

the application of Item Response Theory to security by itself already provides many new directions of study, and may inspire both modelling and empirical research in the .eld.


XOM processors provide the move from NULL and move to NULL instructions to move register data between compartments.These instructions simply change the value of the tag on each register value.

4.2 Handling Program State When a XOM program is interrupted, the operating system needs a way to save the context of the interrupted program, and restore it at a later time.at interrupt time, the contents of the registers are still tagged with the identity of the interrupted program.As a result, the operating system is unable to read those values to save them.


However, such a scheme is likely to encounter severe usability challenges since it requires the ability to perform modular addition mentally, a skill that is arguably difficult to teach to users with limited education backgrounds.

substitution coding is a skill that is known to have been used by humans in practical systems for a long time, although its usage in the above form, and with a developing-world population, remains untested prior to the current work.


When considering the potential system to be used in response to an attack in progress, it is desirable to minimize connection points in between the administrator and the objects being administered.

for the sake of scalability and performance, the three-tiered approach is preferred to the two-tiered.


An adversary, resided at a di.erent location from the legitimate user, will incur di.erent RSS or CIR pro.les.

the RSS and CIR extracted from a single frequency only provide coarse-grained information of the wireless channel and thus the e.ectiveness of user authentication is largely limited.


Second, to prove the security of dPEKS under the known hardness assumptions, we prove that if the security of PEKS (dPEKS) is not guaranteed, it is possible to solve the hardness problems.

it is hard that an attacker A of hardness problems provides trapdoors, test results, and a challenges to an attacker B of Baek et al.


Hybrid intelligent systems can be used for detecting anomalies within a computer network system with a high degree of classification accuracy.

as with most intelligent system algorithms, the accuracy of the output of these systems depends on how closely the input data matches the data used during the training stage.


This is due to inherent support for code mobility by means of dynamic class loading and separable class name spaces, as well as a number of security properties, such as language safety and access control by means of stack introspec- tion.

serious questions must be raised whether Java is actually up to the task of'providing a secure execution environment for tnobile agents.


The features of a view could be the number, types or layout of the visible components (e.g., buttons, menus), or a set of Android platform speci.c APIs invoked in this view s activity.

the former one (e.g., layout) is much easier for an attacker to manipulate because it does not represent the fundamental semantics of an app.


For instance, for private location equality testing, the values are 2-tuples (i.e., longitude and latitude) on the earth and not ordered.

in case of the socialist millionaire problem the values are ordered scalars representing funds in bank accounts.


Note that the resulting scheme is both randomized and tailored for each g,and hence inferior to the construction in Section 4.2.

scheme (4) preserves invertibility, namely, if f is a family of invertible pseudorandom permutations (over (g,r) n + 1 bits) then F is a KDI-secure invertible pseudorandom family mapping n bits into n+ 1 bits.


For example, [31] ensures that password values do not repeat often and [15] computes the distribution by counting the repetition of password values.

for passwords generated using grammatical structures, underlying structure may cause non-uniformity even if the password values are unique.


Overall, 3% of web users who viewed our ad were using a caching network proxy.

some countries had a signi.cantly higher fraction of users behind network proxies.


10 8 6 4 2 bus saturation, which was shown in Figure 7, is the main reason for this upper bound.

since the PCIe bus is a point-topoint link, adding one more GPU device to the system increases the aggregateGPU throughput to over70Gbit/s.


The analysis of existing .le-system implementations indicates that fast algorithms would contribute thousands of lines of code to the TCB (e.g., 2,300 lines of code in the case of the Ext3 .le system).

all the sophisticated algorithms and caching mechanisms are already available within the untrusted commodity OS s .le-system stack.


RISE contains none of the machinery found in TCPA/TCG for supporting DRM.

rISE is designed to maintain control locally to protect the user from injected code.


Legitimate competition in web search is good.

these search engines appear to exist for the sole purpose of showing ads and not for innovating in web search (indeed some don t even show organic results).


Distributed, low and slow scans can be di.cult to detect if the observation is made only within a small time window.

in order for the remote attacker to .nd speci.c system objectives, the collected intelligence must be transmitted back to the remote control and the information together must reveal enough useful information to allow further exploits.


With that help each read or write access of the related MSRs or the time stamp counter could be detected and simulated.

incorporating external timing sources still allows to reveal the existence of BT, a general limitation that we share with all other automated analysis frameworks [3, 10, 40].


between the maintenance cost and the change over cost.

this does not provide a complete solution to role migration.


They assume that sensor nodes are aware of their locations.

our scheme does not have such assumption.


Consuming Sockets with PCTCP: PCTCP may potentially offer performance gains by dedicating a separate TCP connection for every circuit.

pCTCP widens the attack surface and reduces the cost of the anonymous socket exhaustion attack dis  (a) (b) (c) Figure 2: Showing (a) anonymous socket exhaustion attack using client sybils (b) throughput of relay when launching a socket exhaustion attack via circuit creation with shaded region representing when the attack was being launched (c) memory consumption as a process opens sockets using libevent.


5.2 Bishop s Rendition [5] Bishop [5] reproduces the work of Brewer and Nash in his popular book on computer security.

perhaps for brevity of exposition, he treats sanitized objects differently.


We can see the frequency of a.p.INTERNET in D2 is 61.43%, which is similar to the result described in [1].

the permission request frequency declines exponentially as the rank declines.


6 A similar model exists in the business sector where people can be shareholders.

governance decisions here are made based on the quantity of shares that people own.


Generally the attestation techniques based on additional hardware such as Trusted Platform Modules (TPMs) have been considered infeasible in WSNs because of their size, .nancial cost and energy overhead.

recent work has shown that a TPM chip (Atmel AT 97SC3203S)costs US$4.5 when ordered in large-quantity, which is less than 5% of the cost of a typical sensor node ($100).


A DDoS defense system located in the source network faces hard detection challenges, because, due to distribu- tion, it can observe only a small portion of the attack.

the small attack volume enables effective re- sponse and complex profiling that minimizes collateral dam- age.


More speci.cally, the overall time cost is O(n 2)for the KGC, O(n 2) for the cloud server CS1, O(n 2)for thecloud server CS2 and O(n) for each group member.

according to the original scheme, KGC takes time O(n 3)to adopt the Lagrange s interpolation formula and takes time O(n 2) to adopt the Newton s Interpolation Formula; for each group member, it will takes time O(n 2) no matter using the Lagrange s interpolation formula or the Newton s interpolation formula.


conduct a broad survey of vulnerabilities in Android, including standard Java and Android-speci.c security threats (e.g., information leakage through logs and messages) [11].

we focus solely on vulnerabilities that result from exposing intra-application communication.


This plug-in then intercepts the system calls for object creation to generate corresponding events.

after the component objects are created, the IMC is made implicitly.


The popularity of wireless mobility has generated an influx of wireless clients on college campuses throughout the United States.

the popularity has not been as eagerly received by network administrators.


One possible countermeasure is to use a timeout for inter-segment arrival at the client and raise an integrity failure alert when this timer expires.

this requires estimating typical inter-arrival time for each client, which may not be reliable.


policy (C) (since nothing is statically known about history .).

a Mobile program can perform additional evt operations on the object by .rst dynamically testing the runtime state value yielded by the unpack operation.


Eager allocation generally improves performance because the taint-tracking system is free to place the taint storage at a predetermined location relative to the memory value it is tracking taint for, thus simplifying access to the taint information.

eager allocation wastes memory in exchange for better performance because the amount and granularity of taint storage cannot be dynamically adjusted in response to the tainting behavior of the application.


In the worst case for the scenarios we studied, the depth is 6.

it quickly drops to 3 due when ConstructCascadeBF is (re-) invoked.


Theirschemeperformsthe same writes to the FW table for Add and Delete, since each Add or Delete operation reveals an identi.er for the .le and reveals the word identi.ers by the locations that it modi.es in their index.

their scheme never writes adjacency information to the Adj table: it hides all adjacency information at the cost of requiring per-word storage and communication complexity that is linear in the maximum number of .les that can be stored in their index.


In particular, because of the way SSL behaves when errors arise, the attackof[4] canonly slowly recovera .xedplaintextthatis repeated across many SSL connections.

our attacks can recover arbitrary plaintext in an e.cient manner.


Moreover, with the increase popularity of distributed computing frameworks, such as MapReduce [12], the computation of data that belongs to million of users could be split and processed independently in parallel by di.erent workers without the need to recombine the results as in the traditional MapReduce Implementation.

the distributed computation aspect was not the main focus of our paper therefore we don t elaborate it here.


The .rst is a way to limit requests to the server to c per second.

rate-limiting alone will not change the server s allocation to good and bad clients.


During this process, we always keep track of the elapsed time.

the CVE-based evaluation aims to estimate to what extent our system is able to predict and detect new classes of PDF exploits.


If the SASSA database is linked to SARS then it will detect all those who are receiving social grants and at the same time working in the private sector and/or municipalities.

it is still challenging to detect those who are not registered with SARS and who may be working as sole traders and/or other subsistence and non commercial work.


Static (compile-time) tools o.er much better coverage of program paths.

some static tools are designed to identify particular properties that were envisioned by the tool developer [11, 3].


Since t(v', P) = t(P + H '(u',r', M ')Q , P ) ID pub The threshold signature (u',v') is valid for the message M '.

it is hardly possible for the adversary to determine the value u' that satisfies Equation (6).


This can lead to the rejection of a legacy application, even if it complies with the device policy.

with further improvement of the fallback compliance module, full coverage of legacy applications is achievable with the presented architecture.


With our architecture, no clientonly host can do this.

sIP also makes extensive use of proxies for call routing, personal mobility, device mobility, and so on.


More complex models are possible, for example, those that take into account data .ows (taint information) between system call arguments.

collecting and/or enforcing data .ow at end hosts is very challenging, especially on real machines and with minimal performance impact.


In existing trust management systems, the proof of compliance question is answered in a binary manner: either a policy is satis.ed, or it is not.

because CTM is able to make use of more subjective horizontal trust assessment algorithms, policies can contain a continuous component as well.


Technically, this lower bound follows the classical theoretical trend in security: proving lower bounds of security (or anonymity as it is the case in hand) would enable us to guarantee, in the worst time, that our system would perform better than this bound for every user.

considering the average case for achieved entropy might be very deceiving since many senders are not likely to achieve this average bound.


To construct finer granularity path is even more challenging as it requires ISPs to expose their inner policies.

considering the re-active ability of the victim, finer granularity path may be not of important value.


For a user s personal registered or generated pro.le and content data, with the user s consent, the IdPs and Web SSO solution should allow RPs to access the user s personal data as easily as possible.

for a user s social attributes (e.g., birth certi.cate, degrees, credit records, driving records) that are asserted by an IdP, the IdPs should act as gate keepers that protect the con.dentiality and integrity of their customers data and provide only meta-identity information to the RPs.


In this case, the adversary learns the actual location ofthe users(e.g., all ofthem are atthebar).

consider a large cloaking region that encompasses the same number of users.


Alternatively, the use of static analysis (in the kernel and the applications) in the analysis phase can help to deduce all code sections required by the applications.

it can be argued that many applications include a large amount of functionality that is disabled at runtime (e.g., by reading a con.guration .le), and the e.ectiveness of such a static approach would be lower.


Recent studies[20,39]have shown a close-to-linear speedupinthe number of cores.

theCPUis stillsaturatedbythelarge number of diverse and computationallyheavy operationsit needstoperform: network .ow tracking, TCP stream reassembly, protocol parsing, string searching, regular expression matching, and so on.


Various SoDs have been identified in the literature [8, section, we define various SoD constraints that cannot be captured 14, 17, 18].

all earlier researches focus on SoDs in a Table5.


In principle, even if an SSL-protected page provides a login window, there is no guarantee that the logic for the login window s Submit button is properly implemented to send the information securely.

from a customer s perspective, there is an implied understanding with a .nancial institution that an SSL-protected page provided by that institution has trustworthy contents, including handling of contents submitted to that page.


The analytical timeimprovement ratio is a slight overestimate for small variances, and gets worse as the variance increases.

it is still well within a small constant times the real time-improvement ratio.


Most of them focused on exact graph or subgraph matching, i.e., graph or subgraph isomorphism.

because both graph and subgraph isomorphism are NP problems [11], existing algorithms are prohibitively expensive to use for querying a large graph database.


For example, the adversary may run the entire web application in Valgrind [24] and trigger various victim activities with manufactured web requests, recording the control .ow that results from each.

even so, the training step (3) is still necessary to determine the l and u values for the transitions.


However, bc s access decision function denies this request.

bob does have permission to view the desired information.


Likewise, one can also consider internal modules that can overtly transmit users private data to TPA server.

this approach does not preserve user privacy, hence is not considered in this paper.


To visualize the unigram packet frequencies exhibited by a given network protocol, we use heatmaps similar to those in Section 2, with time on the x-axis and packet size on the y-axis.

instead of the time elapsed since the start of the connection, we set each packet s x-coordinate as the log of its interarrival time, that is, the time elapsed since the arrival of the previous packet in the connection.


The use of bridge relays, private or public, may o.er a potential solution in providing persistence to the Tor network for mobile users.

it is accepted that a detailed assessment of the potential impact on anonymity will also be required.


The user gains access to the requested resource if and only if the user s attribute values stored in the certi.cate satisfy the policy of the resource owner, yet the resource owner learns nothing about the corresponding attribute values.

in this scheme the policy of the resource owner is not considered as a protected object and is disclosed to the requester.


When invoking editors via .le explorers, usability is preserved because PIP can infer reliably the .les to be edited.

editors can violate information .ow policies when they are used to edit both high and low integrity .les simultaneously.


The above authentication scheme provides source authentication (like an authentication scheme based on pairwise shared keys) while not precluding passive participation (unlike an authentication scheme based on pairwise shared keys).

we note that there is a possible impersonation attack on this scheme.For example, an adversary can shield node v or jam node v by letting another node w transmitting to v at the same time when node u is transmitting.Later the adversary sends a modi.ed packet to node v impersonating node u.Because node v has not received a packet with the same AUTH key, it will accept the modi.ed packet.


whose strength against password guessing surpasses a threshold using such metrics.

the claimed impact of a small number of changes to formerly weak passwords raises concerns that we may be overlooking possible vulnerabilities in such methods.


A SSFS user uses a smart-card in order to access the .les.

this requires smart-card support on all machines, which may not be practical for existing systems.


In a typical scenario, we expect developers to specify most of the trusted sources beforehand.

some of these sources might be overlooked until after a false positive is reported, in which case developers would add the omitted data source to the list of trusted sources.


For example, one can insert addition noise to interference the power [4], insert the random delays [6], static complementary CMOS logic [3], or the masked logic.

these methods cannot prevent DPA attacks completely because of the power leakage of CMOS Copyright 2010ACM 978-1-4503-0012-4/10/06 ...$10.00.


Recall that our threat model does allow attackers to write arbitrary memory pages in the sandbox that are writable, so it is possible that after the code is emitted in the sandbox and before it is copied outside of the sandbox for veri.cation, the attackers might corrupt it.

the corrupted code still needs to pass the veri.cation.


Also, security policy decisions need to occur infrequently, storing these policies in memory is not as important.

the drawback of reading a policy .le is that policy enforcement decisions may take longer if the size and complexity of the .le increases.


Up to the BoyceCodd normal from (BCNF), decompositions are performed based on functional dependencyat a relation sattribute level.

since data redundancies can also appear between attributes that are interrelated in forms other than functional dependency, decomposition method fails to remove some very basic data anomalies.


three device groups have been anonymized.

these VPN access to the scan system DMZ is granted only three device groups are centrally managed by various service to active members of the research team.


In fact, the space reduction graph allowed several maximum spanning trees also in the undirected case, but the heuristic proposed in [9] did not privilege the one directed towards the initial state.

the worst case traversal time bound has decreased.


In particular, the string-edit distance has been shown to in.uence perceived word similarity in psycholinguistic experiments [10, 41, 58] and in real-world confusions [50].

this glosses over the fact that edit distance does better if the di.erent elementary operations are weighted di.erently, so that substituting similar-sounding phonemes contributes less distance than if the phonemes were distinct.


Ruby [3] provides a taint analysis similar to what our library does for opaque objects.

our work allows for more precision in the analysis for non-opaque objects.


Such a raise of overheads culminated in the experiment involving the Needleman-Wunsch algorithm from the NeoBio library, which brought in a slow down factor of 64 and used 28 times more memory.

the DC s cost seems to be compensated by the huge performance gain on the DP side: the query programs generated by the DC were so ef.cient that they were at least 10000 times faster than the baseline and typically consumed much less memory.


For instance, LPT will detect modi.cation of non-control data by means of a format string attack, or a heap over.ow that corrupts freelist link pointers.

it will miss modi.cation of non-control data by means of a direct buffer over.ow.


Obtaining a reliable estimate of the distribution of the single quantized MDCT coe.cients from the corresponding quantized or double quantized coe.cients appears to be a di.cult task.

it has already been observed in the image forensic literature [6] that the DCT coe.cients obtained by applying a slight shift to the grid used for computing the block DCT usually do not exhibit quantization artifacts.


In practical applications, this might not hold true.

we expect our method to still provide signi.cant detection accuracy as long as the di.erent temperatures are correlated, e. g., due to outdoor temperature or time of day.


OpenSUSE uses a download redirector that sends some requeststo mirrors.

thedownloadredirector serves package metadata and root metadata directly.


A common subset is simply the ability to call setuid().

the sheer complexity of a login server makes it di.cult to trust the entire program.


A node s DRI table contains information about an intermediate node s data forwarding history to its nexthop nodes, for detecting misbehaviors.

every network node is involved in the cross checking process, leading to unnecessary increase in overheads and end -toend delay.


We currently employ a simple greedy heuristic to .nd a set cover, based upon the number of operations in common to each hook and the kernel function.

the number of hooks applicable for each kernel function is fortunately quite small, and if necessary brute-force search can be employed to .nd all possible set covers.


Thegoalof our experimentsisto determine the contention between workloads using different hardware resources and determine whether enough contention exists to mount anRFA.Withperfectisolation,performance should remain unchanged no matter what competingbenchmarks run.

if the isolation is notperfect, then we may seeperformance degradation, and thus maybe able to successfully mount anRFA.


Their devices can also communicate with the web site over a NAT.

they use a specialized web server, whereas our monitoring system uses a web site with common wiki software.


These factors often appear in educational materials about passwords or in enforcement rules during password creation.6 6 A possible exception is the foreign language factor.

we have noticed that many individuals use non-English words in their passwords, based on the belief that it will increase the strength of their passwords.


On the other hand, the external and internal FAR is increasing and in such manner reducing the security of the system.

a FAR value of about ~ 2% is still promising for a continuous user veri.cation during a single sign-on session in manageable home environments.


The DBMS records the access events into the raw event log, which represents the input for the analysis tasks.

the raw event log is not suitable for direct processing, since the data are not properly organized and indexed to allow for fast response to a large number of exfiltration detection strategies.


Due to this reason, all SBCs in the mar 2SIP can run over both TCP and UDP.

voIP service providers prefer UDP, because of its better performance.


User-mode SP has no device attestation capability because no mechanism exists to verify the contents of the DMK.

our authority-mode architecture makes remote attestation possible due to the shared secret (DRK) between the authority and the device.


Simple guards have often been used by military organizations that insist on strong enforcement.

a boundary guard by definition gives no protection from users or intruders inside the boundary.


Once the radio chips are installed in the product, the customer can be tracked and his personal information can be collected by the RFID reader.

many stores have a facility that deactivates the RFID tags after the product has been purchased.


In figure 4 (a) and (b), we maintain roles r2 and r3 as separate entities.

the authorization rules set that produces figure 4 (a) will have 2 authorizations rules with identical attribute expressions such that one of these rules yields r2 while the other yields r3.


For a multi-homed network, it may not be possible to locate a single network vantage point that can monitor all the bi-directional tra.c passing through the customer network.

on one hand, many customer networks use multihoming not for load-balance, but for reliability and faulttolerance.


Why Fear Appeals Could Work Better for Some Users None of the participants followed :regulations on password securiW to the letter.

some of them made more of an effort to behave in a manner that they regarded as security-conscious, or at least were aware of tile dangers to them of not complying with regulations.


We believe that social authentication is the ideal approach for identifying users on OSNs because this method does not request any personal information for validation.

the current approaches of social authentication are not secure enough and have not been well tested.


In order to prevent attacks from an untrusted thirdparty script or cross-site scripting, tracking provenance of data is imperative.

no browser o.ers this security mechanism.


Therefore, we can state at a minimum that the APRNGs of applications based org.webkit are vulnerable.

table 2: Entropy of APRNG (bit) entropy general a .xed our sources devices device phone utsname 43 0 0 ktime 31 25 28 26 CBN 8 0 0 UID 0 0 0 Zygote PID 12 0 0 Zygote Time 20 20 t Application PID 15 5 7 6 Application Time 0 0 0 Buffer 0 0 0 Total 129 50 55 32 + t the problem does not end here.


last name carries the largest amount of information, while .rst name and school name also carries signi.cant amount of information.

knowing one attribute alone is not enough for the attacker to identify the target, or to narrow down to a very manageable range.


Since the malware comes from clients, it can be virtually anything, ranging from botnet bots to ad-and spyware distribution or click fraud.

in general the income generated through the malware will outweigh the costs for the PPI service.


Besides that, deRop needs dynamically executing the vulnerable application in order to locate the gadgets in the ROP exploit.

we stress that this dynamic analysis does not involve running any potentially harmful instructions in the original ROP exploit code.


More recently in Wikipedia we have [20], Information assurance is closely related to information security and the terms are sometimes used interchangeably.

iA s broader connotation also includes reliability and emphasizes strategic risk management over tools and tactics.


Although their protocol supports aggregation primitives such as min, max, median, and count-elements, it also requires several rounds of communication between the aggregator and the veri.er.

our approach minimizes data overhead while providing reasonable security guarantees, which was possible by the understanding of the communication protocol used in V2V tra.c information systems.


Next, we analyze whether the derivation keys { ....L ' } observed by the adversary (or proxy) increase the adversary s by (.... ' .... , ¯.... ' .... ) accordingto(.... .... , ¯.... .... ), where .... <.... ' <.... ' < .....

the con.dentiality of .. and .. ' can guarantee the security of scheme against this attack in terms of the advantage against our scheme.


These include new techniques to detect security infections in client VMs(e.g., [2, 7, 17]), arbitrary rollback [16], and VM migration [8].

most of these techniques are implemented within the hypervisor or the administrative domain.


Lacking that, the most sophisticated system can be defeated simply by bypassing its nodes.

no single system can guarantee wide de- ployment, since that would require dominance of the market --an unattainable goal for many technologies.


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

acceleration recorded by a phone-based accelerometer sensor is not stable over the time.


In a monotonic system, this is equivalent to being able to be ful.lled at the start of its time period.

if we were to simply schedule all obligations for the start points of their time windows, we would not have a worst case scenario, since all the conditions would be ful.lled as soon as they possibly could.


Audits in our system can be conducted periodically, e.g., when a mobile handset has su.cient supporting bandwidth.

traditional AV software is only e.ective when operating continuously, which may pose severe limitations on resource-constrained devices.


By analyzing the experiments, we found that the rootkit was able to locate and modify certain kernel hooks at their original locations.

since now control .ows related to these hooks are determined by the shadows hooks, this rootkit failed to hijack the control .ow and thus was unable to hide the running process.


For example, if qi matches the destination dste of a click event e, we consider qi as a true positive, and mark event e as consumed to avoid matching the same recorded interaction more than once.

if qi does not match any of the recorded user-browser interactions, we label it as a false positive.


UMIP [6], PPI [9] and IFEDAC [7] are more recent systems de veloped for Linux OS and compatible with existing applications.

they do not address the usability issues discussed here.


This allows OS to operate solely on a ciphertext basis, for example it can create a perfect copy of data by copying the ciphertext of a page from one location to another.

as pointed out in prior studies [26, 33, 35], address-dependent counter mode encryption has been shown to be superior to addressindependent direct encryption in terms of security protection and performance.


Bob can access all instances of type Building and all resources that located in these instances.

bob can access GeneratorRoom resources only if they are within certain geospatial boundary captured in a Polygon .


Allowing gateways to get another certificate for the user when the current user certificate nears expiration without requiring user intervention would provide better support for long-running jobs.

it adds complexity and increased risk, so for our initial version, we require explicit user authentication and approval for every certificate issuance.


The slop characteristic can provide the required limits.


Due to their key role in de.ning, implementing, and enforcing strategic security concepts, security polices are extremely critical, and quality assets such as correctness or consistency are essential objectives in policy engineering.

given the large amount of their responsibilities, experiences with policy-controlled systems point out that security policies usually are large and complex, rendering analyses and quality guarantees dif.cult.


Data .ow integrity projects compute a data .ow graph for a vulnerable program using compile-time techniques, and insert extra guards to ensure that the .ow of data at runtime is allowed by the data .ow graph.

static data .ow analysis usually analyzes one single program and only predicts approximations of a program s runtime behaviors, which su.ers from two major drawbacks: limit of tracking scope and accuracy.


We considered overlapping key validation with page decryption to improve restore latency.


Digital signatures are basic cryptographic tools to provide these security services.

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


SOA and related modern IT architectural approaches are also sometimes criticized because of the added cost and the added software complexity they introduce.

that up-front investment needs to be compared to the cost of not adopting modern IT architectural approaches, such as (1) maintenance cost / effort explosion, (2) integration hurdles / costs, (3) costs because re-use is not possible, (4) lost business opportunities because the lack of IT agility prevents the offering improved services to the business side etc., and (5) investments are siloed and stove-piped, and thus hard to future-proof .


Only then can the protocol transaction proceed.

tencent interpreted this step di.erently: it issued the user s ID hash to the relying party immediately after authenticating the user (without prompting the user with an additional permission dialogue box).


Their empirical evaluations on the datasets presented in Table 1 showed that features with better IG ranks resulted in better predictive accuracy than features ranked as medium and worst by the IG criterion, which generally showed that feature selection is needed and IG is a reasonable criterion for ranking features.

the study did not compare ranked IG features against other feature subset selection methods.


INTRODUCTION The classical framework of using electronic signatures is that the signer holds his private signing keys in a secure environment called signature creation device and signatures are created solely by this device.

this leads to a lot of practical problems.


(We acknowledge that an account s follower number may not accurately measure its quality in all cases.

it is still a practical and well-accepted metric to laterally re.ect an account s fame and reputation [2].)


termined by comparing the desired signal strength at the receiver, with the level of interference.

the signal strength of the packet being received, is compared with the interfering power from a single node at a time, rather than using the SINR with cumulative interference, to determine successful reception.


A continuous authentication system should with very high probability, never lock out the genuine user.

it should detect an impostor user within a short period of time, to limit the potential damage that can be done by this impostor user to information available on the computer and to limit the disclosure of restricted information.


Up to 10 mV, the worst case is 14.09% .ipped bits in a signature on the low inter-die variation corner.

the number of unstable bits decrease with the increasing intra-die variation.


The branches that have nodes with weak information gain (higher entropy), i.e., the attributes with less occurrences, are removed (see Figure 3).

an excessive tree pruning can result in a tree with too few nodes to do a good classi.cation.


establish the truthofa claimed identity [38].

unlike identity systems for users, most identity systems for digital resources do not provide a veri.cation service.


BITSHRED-JACCARD measures theproportionalsimilarity between features.

we may want to also measure when one feature set is contained within another, e.g., whether one malware is completely contained in another code.


Inthedigestingphase,themimicrytargetbinariesare .rstdisassembledinto CommonInst structuresbeforedigesting.

in most legitimate executable binaries, there are a small but nonnegligible amount ofembedded data, which mainlyconsist of constants andjump addresstables.


To see why this is required, we first show, in Figure 2, a 4-message handshake that has all the properties the IPsec WG wants for IKE, including mutual authentication and identity hiding (hiding the names of the communicating parties from eavesdroppers), as well as a stateless cookie for DoS protection.

message 3 in this handshake is likely to be sufficiently large that it requires fragmentation, since it contains certificates and must repeat information from the first two messages.


There may be a natural tendency to avoid hackerware in an attempt to prevent endorsing the development of such attack tools.

any information security professional worth their salt should be able to view their systems through the enemy s eyes.


We utilize page coloring as a software mechanism for cache isolation by isolating the color sets that are used to back individual VMs running on CPU cores that share the LLC (i.e., belonging to the same group).

page coloring has the advantage over the cache hierarchy aware core allocation technique in that it does not result in processor under utilization.it is still possible to under utilize the memory available on the platform.For example, if memory required by a VM is not an integral sum of the amount of memory available of colors that are currently unassigned to any other VMs, remaining pages of these colors may not be assigned to any other VM.Also, since cache is exclusively partitioned using colors, the performance of a VM may su.er if VM s working set does not .t in the cache partition.Such performance degradation may be acceptable, as long as the QoS SLA constraints of the VM are satis.ed.


Misuse detectors are similar to modern anti-virus systems where an attack s signature is stored in the IDS for later use if needed.

both types have their advantages and disadvantages, but the future seems to lie within the anomaly detectors area of concern.


Each passpicture and distractor picture in a user s portfolio is shown once and only once in a login session.

[43] does not make it clear how the seven public challenges should be generated in each login session.


However, focusing on particular individual data sources helps to develop highly e.ective speci.c visualization systems.

it is important to cover a broader .eld of scenarios and tasks, to provide better situational assessment.


Our framework also encompasses server-side personalization by setting k =1 in which case the client simply displays the ad sent by the server without further personalization.

higher revenue can be achieved in our framework when the server sends back k> 1 results.


In winner decision phase, the revocation manager opens the signature and identifies the winner.

there are two main drawbacks in the above scheme.


This is typically a safe assumption because incorrect feedback rapidly deteriorates end-to-end performance [8].

an attacker who does not care about data integrity could violate this assumption to induce the sender into injecting many packets into the network.


There are also parallel approaches to OAuth such as Facebook s extensions to the OAuth protocol in the form of OAuth 2.0 [9], Google s FriendConnect [3] and MySpace s alternative called MySpaceID [23].

to the best of our knowledge, there is Algorithm 1 Sample Java code for unbinding data using JSR321 1: try { 2: TPMContext context = TPMContext.getInstance() ; 3: context.connect(null); 4: KeyManager keyManager = context.getKeyManager() ; 5: StorageRootKey srk = keyManager.loadStorageRootKey(Secret.WELL KNOWN SECRET) ; 6: Binder binder = context.getBinder() ; 7: Secret keyUsageSecret = context.getSecret(Passphrase for using the key.


We expended considerable effort integrating full-featured SAML support into the Java security architecture used by GRAM4.

many TeraGrid Science Gateways continue to use GRAM2 or SSH for job submission, for performance, reliability, and other reasons.


Like a traditional reference monitor, a SRM resides within server system environment and mediates all access to digital objects.

a CRM resides in the client system environment and controls access to and usage of digital objects on behalf of a server system.


A naive approach to realize blank digital signatures is that the originator produces n signatures for all n possible instantiations together with the public key of the proxy using a standard digital signature scheme, whereas the proxy simply signs the originator s signature for the chosen instantiations.

the number of signatures issued by the originator would then be O(n), which gets impractical very soon with increasing number of choices in exchangeable parts.


Access Granted Abdulaziz Almehmadi University of Ontario Institute of Technology C:UsersPassDesktopUntitled-4 copy.jpg 2000 Simcoe Street North Oshawa, Canada L1H 7K4 abdulaziz.almehmadi@uoit.ca Khalil El-Khatib University of Ontario Institute of Technology 2000 Simcoe Street North Oshawa, Canada L1H 7K4 khalil.el-khatib@uoit.ca ABSTRACT Existing access control systems are mostly identity-based.

such access control systems impose risks because recognized identity is not essentially an interpretation of good intentions of access.


D is l-session self-healing if 1The term sliding window was also mentioned in [27].

no speci.c technique has been presented there.


a mov ebx,fs:[eax]instruction is executed, it is more likely that eax will have been zeroed out, e.g., due to a previous twobyte long xor eax,eaxinstruction, instead of being set to 0x30.

the percentage of inputs that matched both the .rst and the second condition is very low (0.0003% and 0.0004%, respectively), and no inputs matched all three conditions.


We focus on the schemes of [7, 18] which both have a similar, high-level structure: the public key contains elements g,h in some group G, and the secret key contains the value x =logg h. Signing a message m involves computing s =(H(m))x,where H is a random oracle mapping strings uniformly onto G. Boneh, Lynn, and Shacham [7] use an FDH-like approach to analyze their scheme (but with the optimization of Coron [11]); consequently they lose a factor of qs in the security reduction.

goh and Jarecki [18] use a PFDH-like approach and include the random salt r with the resulting signature; this enables them to obtain a tight security reduction at the expense of increasing the signature length.


During the execution of lines 2 and 3, while p points to i, WS(i) changes to include the instructions in WS(ref(p)).

line ref(p) WS(i) 1 N/A {1} 2 i {1,3} 3 i {1,3} 4 NULL {1} once p s referent object changes to NULL on line 4, WS(i) goes back to its original value.


5.4 Hybrid approach: combining multiple processes with batch requests The use of multiple processes is an effective way to improve throughput.

it is not ef.cient in terms of the bandwidth used between the proxy and the database.


The purchase transaction protocol will be the same as for buying content locked to a single device.

the DRM certificate would actually be a domain certificate, which contains the domain public key.


Prisoners are not allowed to receive grants.

there are some grants issued to people who are in prison and their procurators continue receiving the grants on behalf of these people.


As the rule order is top down, resolving this con.ict requires deletion of order-minor rule P4 from the rule base.

consider a pair of rules P5 and P6, P5 : permit TCP X1, Y1 eq telnet; P6 : permit TCP X2, Y2 eq telnet; such that, ((X1 .


In the de.nition in [2], neither Type-I nor Type-II adversary is allowed to learn the full private key of the user under attack.

for key exchange protocols, an important security notion is forward secrecy.


As one of the most prevalent platforms, Android contains sensitive resources that can only be accessed via corresponding APIs, and the APIs can be invoked only when user has authorized permissions in the Android permission model.

a novel threat called privilege escalation attack may bypass this watchdog.


Finally, with the wide adoption of virtualization in data centers, we also envision that di.erent security VMs can be dispatchedto eachphysicalmachinetoinspect runningguest VMs and their internalprocesses (for .ne-grained execution monitoring).Thisislargely feasibleasthesemanticgap has been e.ectivelybridgedtosupport existingmonitoringtools.

with our current focus on examining individual suspect process for malicious behavior, we believe other interesting applications and opportunities (e.g., performance monitoring andintelligentparalleljob scheduling) remain, which we plan to explore in the future.


The easiest way to keep data secure is to limit access as well as the ability for a user to download data to a desktop.

many institutions have special tools that enable users to download data from secure servers.


Giving out the decryption key to someone allows her to read that record obliviously , and giving out both the decryption key and the signing key allows both read and write access to the record.

the database owner is able to learn the access patterns from all the other users because she knows all the keys.


The evaluation of the value of information, another goal of the risk estimation, has similar dif.culties.

we believe that a fuzzy inference system is a good candidate to support the estimation of access risks.


An attacker could potentially disrupt the control .ow of the application by jumping to a non-corresponding second checkpoint if slack was available.

using the T-ProT technique described in the following section, such illegal control .ow transitions would be detected.


We also note that two main segmentation-resistant mechanisms, namely CCT and interference arcs, have never been used simultaneously in a single CAPTCHA design before.

some hollow CAPTCHAs apply the two mechanisms together, without introducing serious usability concerns in our experience.


Gong proposed a method to securely broadcast different keys to different group members [11].

gong s method results in a broadcast message linear to the group size, while with our method the size of the broadcast message is linear to the maximum number of colluding users, but independent of the group size.


Furthermore, Katz, Sahai, and Waters proposed a novel predicate encryption scheme supporting inner product predicates [9].

their scheme is based on a special type of bilinear groups the order of which is a product of three (or two) large primes, and hence needs to deal with large group elements.


a to facilitate the subsequent error-correction step, a non-minimum length coding scheme is proposed.


In the best case, if the attacker could learn all the inputs used for a function and all the resulting outputs, he could potentially learn much about what was executed.

we evaluate what an attacker can do with a much more limited amount of information, namely crashes and the return values of functions.


Contemporary movies, books, recent events in the news, and high school culture as a whole have all helped in producing an interest in and enthusiasm for information security topics among high school students.

while students have a very keen interest in the field, most have little to no experience with the subject.


Similarly, a system could allow users to select or upload personal images.

this would enable password reuse if users upload the same image for several accounts, which has a security cost and may lead to greater memory interference if the exact same password is not selected for each account.


Di.erent assessment methods have been proposed for speci.c scenarios, to model the involvement of physical processes and human actors.

we perceive the need for a general security assessment framework that will be able to assess a wide range of scenarios, among them traditional cyber-systems, cyber-physical systems and cyber-human systems.


All this work focuses on intermediate services that create new requests upon receiving a request and thus need to be authorized to issue requests.

in scenarios like our location system, where some services only forward requests, this model gives too many capabilities to intermediate services.


The e-tokens are anonymous and unlinkable to each other and to the protocol where they were obtained.

the number of e-tokens that are valid during a particular time period is limited.


With EC-ElGamal, where each ciphertexts is a 320-bit value, transferring the encrypted genome translates into roughly 100GB of data.

this massive data transfer needs to happen only once for many tests that Bob (e.g., a given patient) conducts with Alice (e.g., a particular medical facility).


Access control Isolation and address space integrity provide the building blocks for secure HAP execution under an untrusted operating system.

real systems require usable mechanisms for securely sharing data.


For example, while it seems that users will generally use the highest-level of abstraction available to them, it is still an open empirical debate if one should present a dangerous lowerlevel API or restrict ordinary developers to a higher-level API.

one could present a single API with appropriate defaults.


Thus if Alice is sensitive about the fact that she does not possess a California driver s license, she may be able to hide her lack of possession from many parties by adopting those standard policies.

in other cases, such as the CIA credential example used earlier, no such standard policies will be available.


Further in-depth analysis shows that none of the users who disclose 5 or fewer attributes reveal their phone numbers or email addresses.

the 138 users (0.87%) who put their phone numbers in their public pro.les disclose an average of 14.4 attributes, a three-fold increase compared to the average among all users.


Since the external monitor is capable of monitoring an arbitrary memory region, mitigating this threat seems to be possible by checking the integrity of related PGD entries and PTE entries.

we found that there are some challenges regarding this mitigation methodology.


In other words, A9 uses the IMEIs whose .rst character is 3 to indicate real devices.

5.3.2 A9 vs Non-U.S. Devices A9 assumes that an Android device whose IMEI starts with 3 is a real device, otherwise it is an emulator.


As we mentioned in Section 4.1, the usecase of authentication is not considered in both the OAuth 1.0 and the OAuth 2.0 speci.cations.

the terms authenticate and authentication are still used frequently in both speci.cations.


Other works onlayeredencryption canbe found for H.264 [30], DCT-based [19], Hierarchical MPEG [22], andscalable codecsingeneral[20].

thefour latter works are not directly applicable to the videosurveillancescenario, asnoobjectsofinterestareconsidered(the whole image is encrypted).


A conventional approach to improving reliability and availability of a distributed infrastructure is failure masking through redundancy either information, time, or physical redundancy [10].

redundancy and other generalpurpose fault-tolerance techniques for distributed systems scale poorly, and become technically and economically infeasible to employ when the number of entities in the system reaches thousands [12, 27].


while designing the TRM (that is, in a distributed setting), one has to re-formulate this ideal policy using available authorization information so that it is enforceable locally by the TRM.


They may want to do so to improve their downloading performance, to reduce monetary costs of downloads over cellular links, or, in the long-term, to interact with their peers using Mobile 2.0 applications in which users are not only consumers of content but also producers [5] (so much so that they have been aptly called prosumers [30]).

sharing content introduces the problem of how to .nd reputable sources of downloads.


Escudero and Maguire have proposed a proxy approach that adds location information between the client and the location-based service [10].

our approach, while being quite similar to the previously cited references, di.ers from them by the fact that it is designed to work through the Internet.


In the illustrated con.guration (Figure 2) the assumption is that keypad visibility from the side uncovered by the shielding gesture is blocked by the hand entering the PIN.

an attacker is most likely to be successful from a vantage point behind the shield.


This is because there are 22 nodes with the degree 5 in the original graph.

for r(ß|dß = 20), we can see that randomization can signi.cantly decrease its disclosure risk: the disclosure risk is 100% when we release the anonymized graph without edge randomization while the disclosure risk decreases 0.39 (0.2) when we apply Rand Add/Del with k =2.5%m(5%m).


having an anonymized version of T as a sub-trajectory, where a sub-trajectory is a selection of triples of a trajectory.

this means that there will be k anonymized trajectories containing the single location of T. not all of these anonymized trajectories start at the single location of T. Since an individual s home at 8am is likely to be the .rst location of any individual s original trajectory, those anonymized trajectories that do not start at the single location of T (justpassthroughit)canbe .ltered outby anadversary and only the remaining trajectories are considered.


They found that experts and non-experts show sharp di.erences in which analogy they felt the concepts were closest to, and hypothesized that the analogies might function as mental models.


Consequently, the Service Providers would not issue new User Links to the shared domains administered by the compromised Domain Manager.

di.erent service providers may have di.erent domain policies that need to be enforced, and it is the responsibility of the Domain Manager to choose a policy that satis.es all the service providers.


OpenID and InfoCard allow users to consent to the release of their attributes to RPs.

studies show that users become habituated to consent forms after seeing them multiple times [23, 72, 25].


Therefore, relying solely on a top-down approach in most cases is not viable, although some case studies [13] indicate that it has been done successfully by some organizations (though at a high cost).

the bottom-up approach utilizes the existing permission assignments to formulate roles.


After that, an attestation identity key of the TPM attests the identity of the software component to an external veri.er by signing the measurement.

aRM doesn t specify the root of trust for TrustZone.


Additionally, it requires programmers to provide a summary for each library function to allow the information .ow through library calls, which can be an error-prone and tedious task as many library calls are fairly complex, causing many side-effects in addition to simple return values.

implementing information .ow tracking via binary instrumentation, such as in TaintCheck [34], can track information accurately even in libraries, but suffers from a major overhead problem: it can slow down the program execution by around 37 times too large to be used during production runs against security attacks.


According to one estimation,9 in 2007, the averagefraud amountperIDfraud victimintheU.S.is$5720 (about 9% decrease from 2006).

in most cases, it is di.cult to clearly establish a link between breached data andfraud[16].


As can be seen, the bound provided by Algorithm 1 is an order of magnitude larger than the average state-estimation error for each system.

for each system S we are more interested in the ratio between the worst-case observed state estimation error for all 1000 simulations i.e., maxi=1:1000 l.xSl2, and the error bound M AX l.xSl2 provided by Algorithm 1 for the system.


Assigning the cost value to each node, an attack tree/attack graph can be used to evaluate the security quantitatively.

these approaches do not address the two problems: it is difficult to assign numerical values to the nodes, and extensive experience is required to identify the goal or attack path in the model.


Therefore, although we can approach to the arbitrary area of the memory by using the forensic tool, the method for analyzing the raw data is each other different for each cell phone.

phone hacking and development tools for forensics purpose may also be used to access the memory and other important settings of a phone.


In this paper we propose scalable solutions for the privacy-preservingquery result veri.cationproblem anddevelop a number of solutionsthatprovide atradeo.between the overhead for the owner, the e.ciency of the veri.cation, and the degree of exposure of the owner s database in order to prove the correctness of a query.

it should be pointed out that our solution is directly applicable to the authentic third party data publication and the tamper proo.ng of audit trail problems too (with no modi.cation whatsoever) with the added advantage that we do not need to trust the owners of these databases.


The communication between such dedicated hardware and back-end management systems uses strong cryptography.

the data transfer between applications on the mobile device and so-called applets on the dedicated hardware is often either unencrypted (and interceptable by malicious software) or encrypted with static keys stored in applications.


Our protocol achieves ma.a fraud resistance at a near optimal rate of about 1 2 per time-critical round.

it does not achieve terrorist fraud resistance since we are not willing to introduce weaknesses as argued in Sect.


By our subscription system, the user can access the database as long as W does not revoke his membership.

he can get only the data that he paid for.


When multiple possible incidents are reported, we may follow the same procedure to select the action(s) for each reported incident and compute the .nal action set as a wk of size W to keep track of the neighbor s most recent W union of these actions.


On the other hand, J. M. Orset, B. Alcalde, and A. Cavalli [13] proposed an EFSM-based IDS that uses specifications of routing protocol OLSR to detect anomalies in Ad Hoc networks.

their solution was not complemented by a signature-based component, which made it difficult to detect attacks such as DoS attacks.


The calculus could in principle be adapted to take branching decisions (explicit indirect .ows) into account simply by (1) annotating terms with a context describing which computations the current computations depends upon and (2) update this context based on t1 and t2 in the T-CondT and T-CondF rules.

from a theoretical point of view, the policies we currently have in mind are strongly related to data processing (i.e.


During an authentication process, identity data are transferred from the identity provider to the service provider.

in this model the user usually is not aware which kind of data are actually stored in the identity provider s repositories and to whom it is released.


These approaches either rely on some heuristics or require disassembling the packed program.

heuristics about packed code may not be reliable in all cases and can be easily evaded.


It is recently reported that facial recognition has already been used for commercial payment systems which requires very high accuracy [16].

most of today s smartphones and tablets are equipped with a front facing camera, and the resolution is now typically higher than one mega pixels, which is very handy and able to capture users face in high quality.


At .rst, it appear that we must trust the system call, .le system and block device code that ful.l such a request.

it is possible to include this step inside the TCB by using a trusted wrapper, as described by Singaravelu et al [30], around the .le-handling code.


Among them, skilled signatures are considered to be the most difcult forged signatures to distinguish from genuine signatures, and randomly forged signatures are considered to be easier, because many researchers and competitions report that averaged false accept rates (FARs) against skilled forged signatures are higher than those against randomly forged signatures.


Consider a NodeA which does not hold a valid certi.cate, entering an ad-hoc network.

a certain UserB (where UserB and DeviceB are already authenticated) knows and trusts UserA,so UserB vouches for NodeA in the network.


Guideline 3: We recommend using either Na¨ive Bayes or C-SVM (with the RBF kernel) because both of them meet the strict timing and accuracy requirements of this scenario.

our experience is C-SVM (RBF) provides almost 100% detection accuracy at high attack rates.


copy) should only have access to the .les speci.ed on the command line.

in its common implementation, cp inherits all the privileges of the current user.


Furthermore, some systems have formal proofs that if an application running on the system correctly manipulates labels to implement a policy, then the system will enforce the policy [13].

for a user to have end-to-end assurance that their application implements a high-level information-.ow policy, they must have assurance that the application indeed correctly manipulates labels.


Constroid only provides the interfaces to manipulate data o.ered by the ACP.

we think that the actual security policies required for Constroid can be abstracted in a feasible way.


Under this assumption, solution to the above problem could be inspired from the .delity-preserving whole machine replay idea proposed in [8] and [20].

the original replay technique cannot be directly applied because the replay required by .ne-grained infection diagnosis can no longer be performed on the same online processing computer architecture interface .


Figure 3: Image (left) and its salience map (right).

by incorporating color and structural dissimilarity factors into Eq.


s DCS scheme seemingly satis.es invisibility, as it appears that without the con.rmer s private key xc, there is no feasible way to either extract standard signature s from a given DCS s ' by computing -1 s = s 'x c , or check the validity of s ' by using equation mr e(s ' ,s ' )= e(uv g,a)xc .

this is not the fact as explained below.


When a function is called in HBAC, the dynamic permissions are treated the same way as SBAC; they are intersected with the static permissions of the called function.

when the called function .nishes, the dynamic permissions remain when returning to the callee function.


Besides a physical position, users are also assigned a logical and device-independent position.

binding the activation on roles based on the location information of the user is not su.cient when a cross-border data access to con.dential data is necessary.


2.1 Security Factors Web apps provide cross-platform functionality, reduce developer effort and are easy to update.

these useful properties also make web apps dif.cult to secure.


Both average Hamming distance standard deviations indicate the preservation of a diverse population of con.gurations.

gA+PDM does much better than GA+PVM in terms of average .tness scores.


4.4 Remote Wipe-Out When the SIM card is removed from a smartphone, any service that uses the IMSI as the subscriber identi.cation cannot be requested by this phone, such as the basic call service and SMS.

a smartphone without the SIM card still could camp on an available network to make an emergency call, using IMEI as equipment identi.cation.


Section 3.1 presents the anyWLAN architecture that de.nes administrative domain where the end user is able to move from one WLAN AP to the other without breaking its WLAN attachment.

while moving across di.erent administrative domains, WLAN and IP are updated.


It is relatively easy to design and implement accurate at-tack detection for a DDoS defense system positioned at the victim network because it can closely observe the victim and notice anomalous behavior.

2 the range of re- sponse is limited: large-volume attacks can overwhelm the defense, and attacks deploying seemingly legitimate packets will force the defense system to inflict collateral damage dur- ing the response.


The Open-Source Security Testing Methodology Manual (OS-STMM) [5] provides an extensive list of what needs to be checked during a physical penetration test.

the methodology does not state how the testing should be carried out.


In addition to that, each of the future smart appliances should consist of database to store the information necessary to identify the EPC.

when the product is to be placed in the garbage, the values of Ka and S need to be deleted.


Also, the US Congress has held hearings on digital content protection and legislation requiring copy-protection hardware has been proposed.

it is still too early to see where this is heading.


A plethora of schemes has been developed to secure wireless sensor networks and resilience to sophisticated attacks has been analyzed.

the question of how the adversary could deploy her resources to maximally a.ect the attacked system has remained largely unaddressed.


But it does not answer the question of whether or not animals have sufficiently powerful cognitive capability to support the mental states (such as intention and belief) to deceive each other?

the handicap principle does answer the question that, if the communication is generally honest, what are the mechanisms that enforce the honesty?


INTRODUCTION IT administrators use network intrusion detection systems (NIDS) to protect corporate networks from malware.

to investigate, analyze and mitigate possible malware infections,thenetwork-related informationprovidedby NIDS is often not conclusive.


Surprisingly, the ten-fold cross validation returned the same false positive rate as the one for the full classi.er (1.2%).

the true positive rate dropped to only 33%, compared to the 83% of the full classi.er.


Under normal conditions without spoo.ng, the distance between the partitioned two CSI clusters should be small since there is basically only one cluster from a single device at a physical location.

under a spoo.ng attack, there is more than one devices at di.erent physical locations claiming the same device identity.


Aurasium is designed for reference-monitor capabilities, and we can achieve similar results by intercepting calls to sensitive methods, such as those that require the INTERNET permission.

retroSkeleton can be used for many other ways, such as app UI augmentation or behavior modi.cation like our auto-localization functionality, which would be far more dif.cult to achieve from within a replaced libc.


t1 = t ' 1 + t '' 1 for sending the request until starting to receive contents on the returning path is t1 .

if U2 is to request the same contents by its name, N , the path that the interest would traverse is U2 .


For Bagle.j rank selection with two-point crossover has provided the best average .tness.

for Bagle.k and Bagle.n uniform crossover with rank selection has provided the best .tness.


If X satis.es (f1 U(f2 8f3)),then X satis.es ((f1 U f2) 8(f1 Uf3)).

the other direction of implication does not hold.


When these players follow the established protocol, we expect proper availability of information.

if the players act maliciously they should not be able to compromise the entire system but at worst delay the availability of information.


Suppose W1(m1)= c.K.i W1(m2)= c.K.i W2(m1)= c.K.i W2(m2)= c ' .K.i ' and c c ', and label(K) = L. Then W1(m1) L = W2(m1) and W1(m2) L W2(m2).

w1 and W2 are distinguishable to low users, because the values of m1 and m2 are created by the same encryption operation according to W1, and by different encryption operations according to W2.


Several wormhole detection schemes target both exposed and hidden wormholes [21, 22, 5, 7, 31, 37].

in contrast to SCREWED, many of them[21, 22, 5] can neither detect transient wormholes nor work proactively.


Certainly, not all operations are reversible; for example, operations such as deleting objects may not be reversible.

at a minimum, operations that only add things should be reversible.


Their limited hardware resources allow for easy DoS disruptions, and the local system protection is less mature as compared to notebooks or PCs.

it still remains an open question whether typical adversaries conduct context-speci.c port scans for intrusions.


[2] is the only work that provides a similar analysis of the e.ects of noise on worm detectors.

their analysis is at a very high-level, using a number of mathematical approximations to put rough bounds on detection probabilities and false positive rates.


CAB [14] and PiPA [33] aim at of.oading the analysis code alone to another execution thread, and they are the closest to ShadowReplica.

neither of the two has been able to deliver the expected performance gains, due to (a) naively collecting information from the application, and (b) the high overhead of communicating it to the analysis thread(s).


While, unlike the CFAA, this seems clearer on the topic of access (making a network connection) it remains ambiguous concerning what constitutes authorization.

some guidance can be found in the subsequent examples of unacceptable tra.c provided in the same subsection, including Unauthorized probes and port scans for vulnerabilities.


Figure 4: Impact of history window size n. n =1, 2, 3, respectively, when the percentage of active users in-lar posterior probabilities.

after taking a closer look, we 1 1 creases from 2.5% to 7.5%.


The latter two approaches provide less noisy labels.

even in the cases in which labels can be obtained, it is necessary to be careful how they are used.


Note that we have only proved the impossibility of perfect vqss protocols.

the quantum Singleton bound still holds when exact equality is replaced by Algorithm 1.


In this case MOBIKEv2 is supported which means that the IPsec layer support a change of IP address.

if the application or the transport protocol does not support a change of IP address, the transport or application must be renegotiated, but not the IPsec.


Because the stadium is covered by a single AP, all 20 the chunks of the activity are covered.

this is still not suf.cient to obtain non-zero distance proofs, as all the location proofs inside the stadium are obtained from the same AP.


Passphrases and passwords were forgotten at similar rates, led to similar levels of user dif.culty and annoyance, and were both written down by a majority of participants.

passphrases took signi.cantly longer for participants to enter, and appear to require error-correction to counteract entry mistakes.


Auditing Cloud Administrators Using Information Flow Tracking Afshar Ganjali David Lie a.ganjali@utoronto.ca lie@eecg.utoronto.ca Department of Electrical and Computer Engineering University of Toronto ABSTRACT In the last few years, cloud computing has evolved from being a promising business concept to one of the fastest growing segments of the IT industry.

one impediment to widespread adoption by enterprise customers is the threat of attack by a malicious cloud administrator.


Changing an ACL requires an update to the ACL log, but doesn t change the state of the file system.

deletion from the file system must be correctly reflected in the ACL log lest an incorrect ACL be assigned if the directory entry is recreated.


For the receiver, the anonymity set is n, and the entropy of the probability distribution for a certain node being the sender is Hs = log2(n).

the anonymity of a sender is determined by the probability distribution achieved after the .xed number of hops used in the system.


As before, ROP overwrites the stack with return addresses and arguments.

the addresses supplied now point to arbitrary points within the existing code base, with the only requirement being that these snippets of code, or gadgets, end in a ret instruction to transfer the control to the next gadget.


Moreover, EnCore prevents Bluetooth device tracking and provides strong security and privacy guarantees within its threat model.

privacy risks and usability challenges remain.


5.4 Performance Enhancement TZ-RKP is already designed to optimize the execution time of a single trapped event.

a better performance is achievable when the number of monitored events is reduced.


[9] is the most related work to ours, which utilizes oil-painting e.ect to .lter user uploaded images from their devices.

it inadequately solves the following problems.


Audit data from other nodes cannot be trusted and should not be used because the compromised nodes can send falsified data.

the compromised nodes have no incentives to send reports of intrusion/anomaly because the intrusion response may result in their expulsion from the network.


A mission purpose is distinct from both groups and roles in that it encodes the context in which a request is made or the cause of that request.

groups and roles encode information about users identity or privileges, not their intent.


Of course it may often be undesirable, depending on the importance of some of the obligations in the positive slice.

sometimes there is really no alternative, since some deadlines are hard.


For this reason an IdP cannot rule out that an adversary impersonates as a legitimate user.

many services require a higher con.dence in the user identity, for instance, e-commerce and online banking.


3.3.2 AttackingScenarios The necessarystepsto attack obfuscatedbinary codeinvolvedisassembling the binary code, gaining the control .ow graphs and thenperformingprogram analysis and transformations to undo the effects of obfuscation.

toobtainthereal control .owanddata .owgraphs,a determined static analyzer(i.e.,being aware of the approach taken by BOSH) must .rst derive the whole tag .ow.


We consider an attacker who has control over the communication channels used by the user to store and share data.

we assume that the attacker does not know the secret keys of the users, and cannot control the user computing environments, such as their browsers and computers, and any device used in the protocol.


These scans can be thwarted by using virtual hosts, and requiring that the correct hostname be provided before the Web server returns anything.

the availability of Web sites that provide the set of domain names hosted on a particular IP address allows the attacker to easily overcome this hurdle.


However, in a centralized enterprise environment where the IT department owns all client platforms, anonymity is not an issue.

an IT department normally is interested in a unique identi.cation of platforms joining the company network.


As proof of concept, G-Free has been applied to GNU libc.

to provide full protection against ROP attacks, each linked library and the original program code have to be compiled with G-Free, which might in practice result in false positives if a library is not compatible to G-Free.


The reason is that the if condition in Line 2 of SIMPLE-SECURITY, which is invoked by SIMPLE-SECURITY-BISHOP, is met for o 1 = o1, and therefore it returns false in Line 2.

subrule (b) of the *-rule is trivially true.


The computational demands for encryption of the higher resolution subbands are higher, especially if an asymmetric or hybrid approach is chosen.

communication in the smart grid will have to be secured by cryptographic means, and smart meters are no exception.


The impact may be elevated when the actual mental workload is higher than our CRT tasks.

the login accuracy is lower compared to the normal condition but the difference is not signi.cant due to the same ceiling effect mentioned in Section 5.4.2.


C at time t, we produce an output ot which is either equal to the true observation ct , or to the synthetic observation close tothetruevalue c ' t or completely suppressed, denoted by .. We denote by o1:t the vector of all outputs o1 ,o2 ,...,ot up to time t. In this work, we do not consider synthesis as a possible mechanism for generating value for ot .

theuse of agenerative model such astheDBN allows usto synthesize contextsby sampling theirjointdistribution.


One potential remedy for having to trust today s unauditable proprietary all-electronic voting systems is to add an independent voterveri.ed paper trail that is the vote of record [11], as some vendors are now attempting to do.

this introduces further complexities, and appears to be only a palliative addition to an already overly expensive PC-based solution when compared with less expensive paper-based alternatives that are much less dependent on untrustworthiness of computer systems, such as optical scan technologies (but which of course have their own potential risks).


Half of our participants were Computer Science (CS) students, and they usually created more secure initial passwords than participants studying other disciplines (non-CS).

cS students had more di.culty with PTP than non-CS students, since the memorability of their PTP-improved passwords declined as they chose more secure pre-improvement passwords.


Most of them showed frustration after the second module or even the first module since they did not know what to expect in terms of the required permissions and the number of additional modules they needed to add.

suppose a new application with complex operations is to be installed, administrators would face the same problem.


We initially chose the bookmarklet approach for its .exibility, considering that users would be able to save the bookmarklet on any computer, even where they did not have access to system settings.

we now think that a better approach would be a browser extension.


This is done by spreading authority and responsibility for an action or task over multiple people.

choosing a role concept similar to RBAC96 as the basis for the definition of a set of separation of duty controls, they effectively consider authority only.


Then, the proxy can re-encrypt ciphertexts.

the proxy needs to manage all re-encryption keys, and therefore it is difcult to assume that no private information is infringed on even if the proxy is corrupted after the communication.


However, she could accomplish the goal by targeting shared infrastructures such as the time servers that provide timing information to all the smart meters.

the need for the adversary to compromise a large fraction of the meters in order to be e.ective is indicative of the resilience of the price stabilization algorithm given by Proposition 1 to delay attacks.


We can prove their proofs are of length no greater than h. From the inductivehypothesis, index[AEt,.1] =|AEt|.


For example, the malicious application FarmVile attempts to take advantage of the popular FarmVille app name, whereas the Fortune Cookie malicious application exactly copies the popular Fortune Cookie app name.

we .nd that a large majority of malicious apps in our D-Sample dataset show very little similarity with the 100 most popular benign apps in our dataset.


Functionalities like old-fashioned audio/video playing, navigation, telephone, etc., are going to be advanced by strongly cloud connected applications like Facebook.

connections to the inner vehicular bus system like the controller area network (CAN) are going to be established.


This would allow her to create a fake attestation, i.e., convince the veri.er that the adversary s machine is running trusted Assayer code, when it is not.

the adversary can only extract N TPM keys, where N is the number of machines in her physical possession.


It would be interesting to determine if collecting additional data from each test subject would enhance the accuracy.

it is also important to determine if classification can be performed using less data.


The proposed framework in [11, 12] is suitable for developing new ap plications.

our approach can retro.t legacy applications with erase instructions.


Currently, the simulator supports the DES and RSA algorithms.

it can be readily modified to support other algorithms.


The circuit will function correctly only when these clements arc programmed correctly.

using m emory clements will incur significant performance overhead.


For example, if users are allowed to freely navigate a workspace, independent of other users, the individual user has signi.cant power.

group awareness suffers, as each user no longer necessarily knows the location of other users.


That is, all modi.cations are made to the memory region where the location is in the view of the external monitor.

this is not the case for Register-bound ATRA because the modi.cations on the registers are invisible to the hardware-based external monitor.


In another direction, host-based detection techniques such as traditional signature-based approaches (e.g., anti-virus tools) and more recentbehavior-based approaches(e.g.,[35,36]) have also been proposed.

due to the widely used advanced obfuscation/polymorphism [46] and the requirement of client-side installation, the solutions are not attractive for large scale P2P malware detection.


Cyber foraging refers to opportunistically using computing resources in the currently local environment to help with computationsthat would otherwisebe carried out on a mobiledevice[3].

aVISis aprivacy-preservingplatform thatlives somewhere in the cloud and is owned by the sameperson as the mobile device.


For example, the holder is analyzing the criminal record of several gangs and cross referencing them so as to obtain more valuable information.

he does not want any of those criminals to observe this process by hacking into the system.


It is established in [6] that if the positions of characters are known in challenge images generated by a CAPTCHA, then breaking this scheme is just a pure recognition problem, which is a trivial task with standard machine learning techniques such as neural networks [12].

when the location of characters in a CAPTCHA challenge is not known a-priori (e.g.


One of the core issues that emerged on our network was that many of the machines affected by the virus outbreak (see part I [Nachi, Sasser, Blaster]) had antivirus software.

despite having the anti-virus software, it became clear in the wake of the outbreak that the antivirus data files and subscriptions of many students were out-dated.


This result leads to the Network1 which initiated the attack to the victim server-1.

mS6, after detecting an attack against victim server-2, compares Sout,M S6 with TR5,R6 .The resultant correlation coe.cient (0.0145) is too small to consider MS5 as the next MS for carrying on with the traceback operation.


Until EPP, in both of the figures choose-two scheme is more secure than choose-one scheme.

after this point choose-two scheme becomes less secure than the choose-one 19 5 and Figure 6.


Technically speaking, the solution space for a solution with maximum likelihood has many local optima with similar values for the objective function.

many of these local optima represent RBAC con.gurations that are unintuitive from a business perspective.


One possible approach is to use bit-vector to encode matching results.

for a large ruleset, e.g., 1000 signatures, it needs 1000 bits (125 bytes) per connection, which is memory inef.cient.


Patient-centric Authorization Framework for SharingElectronic Health Records Jing JinGail-Joon Ahn Hongxin HuUNC Charlotte Arizona State UniversityArizona State UniversityCharlotte, NC, USATempe, AZ, USATempe, AZ, USAjjin@uncc.edu gahn@asu.edu hxhu@asu.edu Michael J. Covington Intel Corporation Hillsboro, Oregon, USA  michael.j.covington@intel.com ABSTRACT In modern healthcare environments, a fundamental requirement for achieving continuity of care is the seamless access to distributed patient health records in an integrated and uni.ed manner,directly atthepoint of care.

electronicHealthRecords(EHRs) contain a signi.cant amount of sensitive information, and allowing data to be accessible at many di.erent sources increases concerns related to patient privacy and data theft.


It is sometimes said that search engines and on-line systems are the most daring and successful buccaneers in that they contain content which is either under copyright or intellectual property protection.

in legal actions issuing from these new grey areas, many judges have held that the owner of the content, by not opting out, implicitly grants such systems the license to copy the pages.


Of course, another important axis for comparison is computational (CPU) cost of commitment generation, proof generation, and proof veri.cation.

it is dif.cult to estimate the cost of the alternatives because most of them have not been implemented, and do not appear in the literature in a way that exposes all of their constants.


Because of noise, the outputs are likely to be slightly di.erent on each evaluation, even on the same IC for the same challenge.

cryptographic primitives require that every bit of a key stays constant.


In addition, it is not appropriate for mobile applications as the scanner is typically too large to carry.

the upshot of using cameras is that they provide a contact-free authentication, which addresses hygienic concerns.


This approach is reasonable if a veri.er is implemented in the hardware and the overhead of the cryptographic operations can be ignored.

we need to care about theperformance overhead in addition to the security if we use a software authentication layer to provide .exibility and portability of applications.


Ternary Content Addressable Memory (TCAM) uses brute-force hardware parallelism to achieve fast exhaustive search for packet classi.cation.

it remains unknown how to apply TCAM for the SPMSM problem.


Speci.cally, if we consider the stack used in a ROP-based program as its dispatch table and esp as its pc, the ret instruction at the end of each returnoriented gadget acts as a dispatcher that advances the pc by 4 each time a gadget is completed, i.e., f(pc)= pc + 4.

all ROP-based attacks still rely on the stack, which is no longer necessary in a JOP-based attack.


Microsoft has recently released an updated version of CardSpace, known as Windows CardSpace 2.0 Beta 27 .

in this paper we refer throughout to the CardSpace version that is shipped by default as part of Windows Vista and Windows 7, which has also been approved as an OASIS standard under the name Identity Metasystem Interoperability Version 1.0 (IMI 1.0) [28].


Our model does not directly support the concept of sessions.

if we were to introduce support for changing the system graph, we could employ a User-session-role relationship.


Access control systems for Web publishing [2] provide more information about the policy if con ditions needs to be changed for access.


Often triggered by a major news or sporting event, the individual clients that participate in this phenomenon are not malicious in nature.

the aggregation of their actions is detrimental to the availability of the site under consideration.


A Wilcoxon Signed Rank Test revealed a statistically signi.cant di.erence between OpenID and IDeB in the perceived ease-of-use and privacy control for all sub-tasks (z = -3.331 to -4.774, p<.001, with a medium to large effect size, r =0.40 to 0.57).

the test did not .nd a signi.cant di.erence in the perceived security protection provided by OpenID and IDeB.


Authentication times are now linear in the size of K, and thus K cannot be too large; typically K = 10 provides much better performance than BLAC.

when combined with rate limiting, PEREA would 1schemes supporting digital cash can easily characterize misbehavior such as the double spending of a coin.


This mechanism induces a high performance overhead (30x to 50x for TaintCheck [47] and DYTAN [17]).

we believe that ROPdefender can be incorporated into existing taint analysis systems.


Furthermore, since we can calculate from the timestamps on the sequence the driving time between the known location and the destination, the possible areas of the target can be roughly determined.

even under these constraints, collecting speech-length sequences in a large scale is still dif.cult: our driving simulator takes 2 to 5 minutes to complete a 10-mile route in Bloomington (necessary for getting all the speech elements on the route), which is much faster than a real drive, but still too slow to handle thousands (or more) of possible routes we need to inspect.


This shows that per user, the number of other Google users that choose to reveal their pro.les is slightly higher than the number of users that hide their pro.les.

this provides only a rough approximation of the number of non public pro.les, as our crawler only collects unique public pro.les, and is unable to reveal uniqueness of non public pro.les.


The round function can be categorized into two classes: Feistel Networks (FN) and SDN.

the security level depends on the number of rounds, which leads to a trade-off between high security level and required computational time (high complexity) and consequently high energy consumption.


DSR can help to prevent ROP attacks by decrypting attacker-injected code pointers to random addresses.

data randomization requires recompilation of programs, which hinders its practicality.


The process terminates when this di.erence equals m1 = -D or m2 = +D > 0, or until a particular maximum neighborhood size Nmax is reached.

for Nmax = *, the process will always terminate at either -D or D. the average number of steps should be smaller when qi = 0, because of the fact highlighted in equation (10).


We do not expect taint analysis to be an exception to that.

assuming the policy untrustworthy data should not reach sensitive sinks, some taint analysis may be unsound due to implementation details.


Multiple I/O requests can be handled by CloudVisor in parallel.

with the increase of the number ofVMs, thebuffer cache usedby theCloudVisor agent willbe stressed.


On the IdP side, there are over one billion OpenID-enabled user accounts provided by major CSPs such as Google, Yahoo, and AOL.


An organization that does relatively little business online may well not only be a less risk for an incident (such as email virus or denial-ofservice attack), but may be able to respond by simply disconnecting an affected system [Osborne, 2001].

few organizations find themselves in such a simple position.


At time t, user U possesses the RSA chain accumulators Ck, where 0 = k = t. The tampered accumulators CT i and CT j are presented to the auditor A by the user U, which correspond to the locations Li and Lj , and i < j .

the auditor only accepts the claim of location provenance if and only if the sequential derivation of the accumulator from CT i to CT j is successful.


A large value of t has the disadvantage that a machine that has just joined the network will need to wait longer before it can have a valid solution.

once the machine starts solving puzzles, it will solve them for the proceeding cycle, so there will be no delay after the second period following startup.