We successfully identified all 9 port-scan attackers, including both obvious and subtle attacks involved in the two weeks of data.

none of the teams competing VAST 2013 Challenges could detect all the subtle port scans, and most failed to detect any subtle port scans.


Writes update the corresponding location in the bu.er U immediately with the newly written block.

unlike reads, writes also cause updates to a hierarchical log as explained later.


For example, if the little .nger is used to draw an arc pattern, the center would be at a position of the joint between the little .nger and palm where its radius is speci.ed by the length of the little .nger.

while the drawing pattern is expected to be an arc (a smooth and continuous curve), this is not always the case.


Fast Ethernet technology was used to connect the RPi with the PC server through CISCO switch.

the RPi can support the Wi-Fi, Bluetooth, IEEE802.15.4/ZigBee, and GSM protocols once the extension modules are installed.


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

no complete solution is offered on how to perform a better malware clustering validity analysis.


Note that the components of A(P) have the same type as those of security automata.

automata in CSP only accept .nite sequences over the set S, called traces.


The XenBlanket project [51] uses nesting to address the problem of in.exible control and cloud provider lock-in, and allows clients to implement their own services.

while these projects address the individual concerns above, they do not address both of them simultaneously.


Scalability: Our solution should scale to commodity Android binaries, which could consist of hundreds of thousands methods even for pre-loaded apps and libraries.

algorithms for graph-based comparison (i.e., isomorphism) usually have high resource demands.


In the original NY transform for PKE, the ciphertext of a resulting scheme consists of two ciphertexts that are decrypted to a common plaintext by respective decryption keys.

this method cannot be applied for KEM straightforwardly since it is not generally possible to choose a common DEM key for two independent ciphertexts.


The codebook-based method has higher mean compared to LSB-based media.

it should be noted that without the knowledge of original cover media, it is hard to differentiate and detect the presence of covert channel.


Of.oading security decisions to a user is not the best idea.

we imagine that in the absence of a proxy like setting or an umbrella webstore, client side defenses on mobile devices would be limited.


Today s high-performance IDS engines often meet these challenges with dedicated network processors [1, 3], special pattern matching memory [30], or regular expression matching on FP-GAs [12].

these hardware-based approaches limit the operational .exibility as well as increase the cost.


All of these methods are based on some preliminaries, such as language knowledge or trained model.

our method is context-free and geometry-based.


Discussion: Several of the above techniques are quite simple, in that they perform optimizations that would seem obvious to an experienced cryptographer.

many optimizations (e.g., Technique 8) could have been applied in published algorithm descriptions, and yet were not.


An attacker can forge any of the information present in sent packets.

position information plays an important role for proper implementation of position related VANET applications.


First, the similarity measures make sense in terms of their relative values.

we still do not understand what a speci.c similarity measure represents.


In normal operation at R0, a packet that arrives at R0 destined for R1 will be routed through the appropriate channel to reach its destination.

the routing table in R0 can be modi.ed such that for packets destined for R1, instead of being routed through the West output port, the packet is re-routed towards the East output port (as shown with the dotted line in Figure 7).


If the rules de.ning a policy are left-linear and have no superpositions (no critical pairs) then the rewrite system is con.uent, and therefore the policy is consistent.

some of the systems used to de.ne policy combiners in Section 3 have critical pairs.


So far, access control has been seen as only fully outsourcable.

we believe that access control can be partially outsourced.


The total amount of functions in the compiled source files (x86-64 architecture, default configuration) is 151,845.

only 23,835 unique functions in the kernel source code used some system call directly or indirectly.


The feature of adaboost is that its classified results are decided by many classifiers, so it makes classified results more accurate than unique classifier.

adaboost is sensitive to noisy data, so it inclines to introduce overfitting problem.


4.3 Making new transport protocols Along with the development of network technology, the corresponding transport protocols have been constantly perfected.

the actual survey found that the optimization of transport protocols was just to add parts of content, instead of modifying the body of protocol.


As shown, all the protocols cost close to their optimal number of phases when the probability of being unavailable (p) and the number of users (N) are small.

unlike our protocol, the costs for all three protocols increase exponentially with N and p (note the log scale of the graphs).


In practice, static integrity of the TCB can be insured by means of secure boot.

the TCB is still vulnerable to runtime attacks subsequent to a secure boot.


Guessing the symmetric key with a brute-force attack is computationally very dif.cult; while a host knows that the encrypted addresses provided to it are obtained from base addresses that have a common set of bits, exploring the entire key space to identify the secret symmetric key is computationally challenging (e.g., our prototype uses TDES for encryption, where the key space has 2168 keys).

best practices for key management require ISPs to periodically change the encryption keys.


The underlying assumption is that real users will implicitly understand the outcome of their authentication attempt by the presented data; i.e., an unfamiliar account will indicate that the entered password is incorrect, and they need to try again.

a random attacker may have little or no idea what to expect as user data after being logged in, even if she launches a humanassisted attack.


Capacitor C needs to be discharged through node QB.

the charge of capacitor C makes the voltage of QB rise to certain level (Vrd ) transiently.


There was also an assumption in the original software of the identi.ers being usable as .lenames to maintain an audit record of issued credentials (a requirement of IGTF accreditation).

some of the characters were meaningful to the .le manipulation routines (e.g., forward slashes which represent a path separator under Unix).


Li and Winsborough [34] proposed a role based trust management language to represent the credential and further introduced algorithms to discover the credential chain even in the distributed credential storages.

those algorithms require the complete information of the intermediate nodes between the issuer and subjects, That is impractical in Ad hoc networks as well.


Therefore, a smooth operation of SIP servers (CSCFs in IMS) is vital for any service operator.

the popularity of the VoIP and IMS based services is now receiving an ever increasing attention of imposters or intruders towards these infrastructures.


ISSUES AND LIMITATIONS Later in the paper, we propose four types of anti-worm propagation methods: a passively spreading anti-worm which responds to worm probes with a counterattack; an activescanning anti-worm which actively .nds targets and propagate to them; a hybrid scheme that combines the features of the passive and active anti-worms; and an IDS based antiworm where an IDS or similar device intercept attack messages and counter-attacks [21].

the proposed antiworms in their current forms have several unresolved issues and limitations that are almost certain to cause serious deployment problems.


This tool provides a compressed visual representation, which is very good to catch the overall global similarity of many time-series.

if you need to explore many time-series in detail using the lens, the scalability degrades.


User studies have shown that users can remember these types of passwords well, and for long periods of time [3][31].

the PassFaces example demonstrates relatively weak security, comparable to that of a four-digit bank card PIN (see section 1.2.2 for a discussion of password strength).


With .xed number of nodes, for both basic and expansion model, as the cell size expands, the communication cost grows as well.

the cell expansion model brings forth more traf.c since each group includes more nodes.


Given a coordinated attack signal, these networks of compromised phones are more likely to detrimentally affect communications on a nation-wide scale instead of just a single area code.

as we discuss in the next section, it is still possible for bottlenecks in the wireless portion of the network to prevent such an attack from being carried out.


Furthermore, let cnt be the current value of the counter keeping track of the number of times that the TPM has run the Join protocol.

alternatively, the TPM is allowed to re-run the Join protocol with the same cnt value many times.


Further, since all keys are dependent on passphrases that are associated with directories, in the case of emergency (password compromise) changing a passphrase for a directory should result in re-encryption of all the .le located in that directory.

to the best of our knowledge, CFS does not provide any such mechanism.


The delegation is authorized by applying policy 1.

if Bill wants to delegate QE1 to Sree, rule engine tries both delegation policies.


Values in categorical .elds cannot be ordered or added.

it is possible to count the number of unique values in the log .le for this .eld (i.e., how many categories there are), the distribution, etc.


Initially, the server operator may simply deploy a single .lter in front of the server.

to combat network-level attacks, the server s operator may contract with its ISP to deploy .lters at the ISP s ingress links.


Under normal circumstances, this prevents Joan inadvertently removing a needed role.

in some situations, such as when Bob leaves the company, Joan must be able to force the role revocation and in this case must remove or reassign Bob s obligations.


For instance, a LTL formula de.ned over the agents states can be (automatically) translated into an invariant, i.e., a never claim, and applied to the Promela agents.

the properties we want to verify here are related to the messages sent from applications to the platform, i.e., the system calls.


Accelerators that perform entire large-scale operations (such as an entire key generation or signature) on-chip using an internal random number generator would cause similar problems, and likely be unusable for these FSS constructions.

accelerators that only provide hardware assistance for cryptographic building blocks such as modular exponentiation or large number arithmetic, would cause no problems.


The only use of reconstructing K in this manner is to attempt to reverse engineer the behavior of the PUF.

recall that our design involved hashing the PUF output when creating the keys.


Therefore, numbers of pairs are increased in location map to improve the capacity of embedding information into the cover image.

the capacity of embedding information decreases 18 bits when it increases one minimum point in the location map each time.


A common practice of malicious PDF authors is to scatter this code across many objects with the aim to hinder detection and analysis.

no matter into how many objects the code has been split, in order for the original codetobe executablewhenthedocumentisopened, the respective objects (or their associatedparent objects) should all have been marked as containing JavaScript code using the /JS key.


In section 2.2, we already mentioned that what SQL predicates are equal to whole-stream policy, up-stream policy and down-stream policy.

for understanding easily, in those predicates we directly used the values of EPC and time.


RESEARCH GAPS Much of the above discussion could be easily dismissed as engineering challenges that are beyond the scope of the research community.

if we dig a little deeper, we begin to see places where research can help.


Probability Distribution Of Silence Sample Values Probability Distribution Of Silence Sample Values 0.5 form, we may doubt if there is really any DC offset component 0.7 0.6 present in the caller s audio stream.

if we look more 0.4 0.5 closely, especially in the caller s silence, Figure 2 (bottom) shows how the sample values are shifted below zero toward negative val ues.


Autonomous mobile agents .will become increasingly im- portant in electronic commerce settings.


The security notions for our labelled algorithms are similar to those of standard signcryption, with the added requirement that t is considered part of the ciphertext (for the purposes of CCA decryption oracle queries), and must be authenticated.

there is no hiding requirement for the label t. As expected, the security for signcryption consists of IND-CCA and sUF-CMA components when attacking some user U.


Servers may also be able to mitigate the attack by using JSON responses only for HTTP POST requests; the script tag always generates GET requests.

this may require signi.cant redesign of the web application.


Furthermore, our high-level privacy protection schemes hide locations in some sessions that are critical to the user s privacy.

as noticed above, a considerable number of the sessions will be released.


the other branch of an if-block) may lead to omission errors, where implicit .ow occurs because there was no information .ow in the intercepted trace.

recent research found techniques to conservatively reject programs that try to transmit information using these channels.


The .rst category represents nodes that generally exhibit high levels of trust in the members of their trust set.

the second category represents the nodes that are inclined towards low levels of trust in the members of their trust set.


This is con.rmed by our analysis: 80% of bots we detected on Facebook used the mobile site to send their spam messages.

to create an account, it is still necessary to go through the non-mobile version of the site.


Total number of characters in words, but that is not better than the performance of JTR GW25-8 (34.7%).

grammar-aware cracker cracks the passwords tends to remain the same as the num 10% new passwords from P16S dataset.


Normally, this requires a modi.cation of the target system.

the PHP architecture was designed for extensibility, allowing developers to add new or modify the existing functionalities.


Their solution provides more security than [3] because number of words in a document are not disclosed.

it is less e.cient and does not support arbitrary updates with new words.


However, the protocols proposed to satisfy this requirement are not zero-knowledge with respect to the underlying watermark but only with respect to their form:  these protocols show in zero-knowledge that the watermark has a certain form, e.g., WM = g x mod p without revealing x := logg(WM).

they reveal the real watermark hidden in a list of fake watermarks, hoping that the veri.er does not discover the real one since all watermarks in the list are detectable in the corresponding work.


To identify sources of observable artifacts, we need to access all the objects in the Android OS.

it is infeasible to do so in o.-the-shelf Android devices due to the application sandbox and lack of root privileges.


This solution is referred to as PGP Web of Trust.

one limitation about PGP Web of Trust is that it imposes restrictions on the signature feedbacks of certi.cates.


In these ways, A5 is adaptable to existing research environments that have different work.ows or special needs.

for the general user of A5, the more useful form of modularity comes from the post-analysis plugin framework.


In biometric systems, the transformation function needs to transform the query template into another template which is expected to be the same as the registered template by taking care of the acquisition variability.

unlike other areas such as communication systems or data storage where there is only one class of data, biometric systems need to deal with two classes of data, that is intraclass data and interclass data.


For example, an administrator in UseCON is able to .nd all the (requested, activated, denied, completed or stopped) usages that are related to a particular object.

using UCON he is restricted into retrieving the value of the object attribute that contains only the number of its previous (completed or terminated) usages (as proposed in [9]).


Recall that the equality test does not help in identifying the deviating party.

a false function attack can be readily detected by simply asking the parties to prove in zero-knowledge (ZK) that they computed the garbled circuit correctly.


If the policy respects the user s preferences, the web browser retrieves the web page.

if the policy does not respect the user s preferences, the browser may block the site or notify the user.


Thus, the same sequence of user actions might cause rendering slightly different webpages.

such variations do not change the overall picture.


As these protocols avoid the use of digital signatures, they introduce asymmetry in one of three following ways: using information asymmetry, using time asymmetry, or by combining both approaches.

multicast authentication protocols supporting non-repudiation attempt to amortize the overhead of a digital signature over a group of data pieces (that is, packets1) or to reduce the online computational e.ort with the use of hash-based one-time signature schemes.


To this end, BABs only support authentication, while PIBs allow signatures for veri.cation using public keys.

instead of using BABs or PIBs to verify relayed Bundles, we utilize IBR-DTN s support for SSL on the TCP convergence layer.


Cryptographic parameters have been successfully retrieved: 402000:8 and 402008:8 as inputs, and 402000:8 as output.

we also collected parameters with values linked to this particular implementation: (i) eax:4, ebx:4, esp:4 containing memory addresses, (ii) ecx:4, containing a counter value, (iii) 12FFC0:4, corresponding to a local variable initialized before the loop (SIZETODECRYPT), and (iv) edx:4, an intermediate storage.


The new subset sum public key cryptosystem of two dimensions, which is proposed by Kasahara, Murakami and Nasako, decrypts the cipher-text by erasing the secret random elements which are added in the public keys of each dimension.

the sender chooses a random sequence and concatenates it with a message vector at the encryption.


Relatedlanguageshavebeen studied,forinstance,by Abadi andManna[1] andOrgun[17].

we seem tobe the .rsttointroduce a new operator toDatalog, and show thatit canbe reduced to existential quanti.cation in Datalog.


WSBAC also requires that encrypted .le accesses originating from untrusted devices be decrypted at Polen (rather than at the network .le server).

because both Polen and the network .le server are administered by Alice s employer, decrypting .le accesses at Polen compromises her privacy no more than decrypting them at the .le server.


In order for the PIS to grant the request from the subcontractor, the PIS needs to be presented with the appropriate information that the portal properly delegates its all or a subset of privileges to the subcontractor.

the subcontractor needs to demonstrate valid delegation information to the PIS.


When users use these metrics to express their privacy requirements, at least three elements should be provided a metric, the parameter values of the chosen metric, and the history window s size.

in practice it is dif.cult and cumbersome for a user to give exact values to these elements, as this requires them to understand the meaning of each parameter and the corresponding implication on privacy protection.


The scope can also include a list of controllable properties, as discussed in Section 3.1.

for readability reasons, we refrain from showing them in this section.


An important reason for the insecurity of web applications is that many programmers lack the appropriate knowledge about secure coding, so they leave applications with .aws [7].

the mechanisms for web application security fall in two extremes.


We found that in the short-term, participants had more dif.culty recalling multiple text passwords than multiple graphical passwords.

after two weeks, both groups had signi.cant dif.culty remembering their passwords and there was no statistical difference in success rates.


To achieve thisgoal, a common approachistopatchtheknown system/software vulnerabilities within the machines.

there is typically a long time window between the identi.cation of vulnerabilities and the release of the corresponding patches, not mentionthatthere areprobably many zero-day(unknown) vulnerabilities inside our software.


Currently, we are consideringall timingsin our experiments.

astheusersget morefamiliar with thekeypad,the timing patterns might change.


This kind of behavior could perhaps be enforced by using triggers to update access privileges when a database changes.

this is not an ideal solution because a policy may depend on a table for which the policy de.ner does not have su.cient privileges to de.ne a trigger.


This would prevent a single compromised service from launching arbitrary attacks on a cloud service of its choice.

cloud services have complex APIs and interactions.


how to best allocate sybil machines to these roles.

by running the experiments multiple times, it became clear that the resources we allocated for responding to update messages sent to the fake repeaters were inadequate, since large number of messages that were addressed to the fake repeaters were dropped, simply because the service queue was being .lled.


they all require some actions (e.g., clicking a phishing link or starting a connection .rst) from the victim, thus restricting its practicality.


In particular, encrypting .rst the message and then computing the MACfunction over the ciphertext is usually preferable since the encryption function does not have to be computed in CBC mode [9] and invalid ciphertexts can be discarded without the overhead of decryption.

direct authentication of the plaintext is a desirable property, and also notice that we employ the MAC to authenticate messages that are not necessarily private and that can be predictable or induced.


For instance, [21] shows that in-home activities could be inferred from realtime energy consumption data.

to our best knowledge, there has not been any work on protecting appliances physical security, especially at the presence of untrustworthy external inputs (control commands and prices).


There is a performance penalty when developers convert a program from entirely local execution to involving RMI.

the benchmarks in [6] indicate that our technique adds no signi.cant additional cost over the base penalty for using Java RMI.


From the sub ject s perspective, it has promised to take action a during the given time window.

from the system s perspective, it also implicitly promises that if everybody else ful.lls their obligations, then s should have the needed privileges and resources to take action a.


There are times when an attacker may be unwilling to wait for multiple keystream reuses; perhaps they are very rare events.

if the two plaintexts are of two di.er- Training corpus size, type of correctness Figure 4: This graph illustrates the ma jor problem that is encountered during the reconstruction.


We assume the attacker has control over the wireless channel between the two phones and is able to intercept, modify, delay, or inject messages.

the attacker does not control human-observable channels between the two phones (i.e., the visual or vibration channel).


The BitTorrent has been generally used for distributing large volume open source software, such as Linux distributions.

students were downloading and/or uploading copyrighted music files.


A DSLibcanbe executed either in the local address space, or on a remote host (in a di.erent address space).

communication with a remote instance is by traditional RPC, and requires the marshalling of arguments.


The Government is expected to introduce the bill into the Australian Federal Parliament in February 2000.

it has not yet appeared on the bills list for 2000.


5.1 Adversary Model On the hardware side, we consider an adversary who can perform simple hardware based attacks, for instance attaching a debugger on slow system buses.

we assume the adversary is not able to carry out sophisticated attacks such as high-speed bus snooping or similar.


The same as EIA1, EIA3 is also claimed to be GMAC.

figure 2 suggests that it is much closer to XOR MAC.


Also, the TCP slow start behaviour is not modelled.

as most worms are rather of small size, it could be represented by choosing a lower bandwidth than the actually available bandwidth.


All of these web site testing systems use hardware-level virtual machines to host web browsers.

we have developed a web site testing system based on FVM, an OS-level virtual machine technology.


Parameter pi,j shows the transition probability from hi to hj and it is determined based on CVSS scores of all vulnerabilities of all running services of hj which are accessible to hi [18].

these transiwhere ß is the damping factor [15].


This protocol provides a straightforward method of creating a symmetric session key between two parties to be used for message encryption.

the Diffie-Hellman protocol by itself is vulnerable to a man-inthe-middle (MITM) attack.


To address this issue, many approaches to secure routing in WMNs have been recently proposed, see [3].

none of these protocols has been adopted in the practice.


Such situations account for the probability that nodes or the judgement system make a wrong decision.

assuming a global majority of benign nodes in the network, our analysis shows that our scheme works in favour of the good nodes in the network.


Reliability:The response of a particular PUF instance for the same challenge may vary due to environmental variations (temperature, voltage supply noise) and temporal variations (aging).

it is desirable for the challenge to be relatively stable so the PUF can be used as an identi.er or key.


Albeit he might not make use of the entitlement, he/she still has the permission .

the permission p2 is not shown in the generative RBAC model as it has not been utilized (cf.


Current proposals for capability-based systems treat prioritized traf.c (i.e., packets with a valid capability) preferentially over non-prioritized traf.c.

capability-based systems still suffer from a critical weakness: they cannot protect the initial capability request, because that request is sent unprotected as non-prioritized traf.c.


The Disappearing Stroke technique is the second best defence.

in many circumstances, both techniques worked equally well (see Tables 2-4).


Those studies also assumed that a large amount of time was available in advance of capture to obtain the electrical parameters of the target display.

this paper demonstrates that such EM display capture is feasible in real time by a setup that fits in an attaché case.


Further experiment will be required to quantify the effect of the VAP.

it is fair to claim that our performance evaluation shows positive results of the effect of the VAP.


Balfanz, et al., have proposed using locationlimited channels for location-based access control [3], and many others have also proposed use of limited-range radio broadcasts as a way to verify proximity [13, 6, 5].

there are no strong security guarantees that the communication range will always be limited as desired: an adversary with more powerful equipment may be able to participate in the protocols even if they are substantially further away than non-malicious parties.


of Florida State University Ottawa, Ontario K1V 1A7, London PO Box 4530 Canada Egham, Surrey, TW20 OEX, UK Tallahassee, FL 32306, USA carlisle.adams@entrust.com mikeb@dcs.rhbnc.ac.uk desmedt@cs.fsu.edu  Mike Reiter Philip Zimmermann Bell Laboratories, Lucent Technologies PGP 600 Mountain Ave. Menlo Park, California, USA Room 2A-342 prz@pgp.com Murray Hill, NJ 07974, USA reiter@research.bell-labs.com ABSTRACT Several organizations are setting up Public Key Infrastructures, examples are: the Corporation for Research and Educational Networking (CREN),  the Federal Government plans to fund 7 Public Key Infrastructure Models pilot programs at different federal agencies.

experts have quite different viewpoints on how to set up such Public Key Infrastructure (PKI).


The table shows that none of the access control methods, except ours, can support delegation of access-control rights.

efforts have gone into incorporating a delegation mechanism into RBAC.


Support for extrusion detection would be a valuable addition to many commodity firewalls and intrusion detection / prevention systems.

the second issue concerns the reliable implementation of such support.


In particular, the XACML pro.le for RBAC [1] provides a mapping between RBAC and XACML by introducing new specialized policy sets.

the current RBAC pro.le does not provide any support for many relevant constraints, such as static and dynamic separation of duty (SoD).


MashupOS proposes HTML extensions such as  and , which occupy a middle ground: they allow the caller and callee to communicate but only along well-understood channels (as opposed to across the whole DOM under the status quo).

mashupOS has the same limitations that DAC-based operating systems have: the user (or the integrator in MashupOS s terminology) must still decide apriori whether to trust a third party or not with sensitive data because sandboxed scripts in MashupOS can leak data to external servers.


For example, OSCAR logs accessing demographics data for patients.

oSCAR does not log accessing allergy or medication lists.


Therefore, the instance in , (ycEE ,QeEi ,yeE, e:e), is also true.

if (yE,QE,yEe:q)is true, then there exists a reachable state ycE1in which QeEis true.


Using these groups, we achieve the DDH-based anonymously revoking method with short signatures (Very recently, the solution is proposed in [8]).

in this case, implementations of two elliptic curves are required, which is an overhead.


The CRL is also executed in this step and it is saved in the DMZ.

the growth of the number of users in the UAE it was a concern, but the system was evolved to support the scalability, reliability, along with security needs.


The sending application is noti.ed when the acknowledgment arrives.

the lack of a MAC covering acknowledgments allows an adversary to forge an acknowledgment for any packet.


There were many connected components Si (j) belonging to extracted subgraphs that survived this pruning.

we were not satis.ed with most of them because of the fol (j) lowing reason.


Therefore, users are likely to better create their graphical passwords by o.ering appropriate user guidelines.

seldom studies can be found in the research literature with the purpose of exploring the e.ect of user guidelines on graphical password creation.


Conceptual knowledge is knowledge about concepts or relationships that can be expressed as propositions (e.g., URLs have a protocol part and a domain name part).

procedural knowledge (also referred as declarative knowledge) is the step-by-step knowledge that one uses to solve a given problem (e.g., check the URL in the address bar, and if it contains an IP addresses, you are likely visiting a phishing site) [2].


iOS users were mostly unaware of data usage by the apps (iOS 6 was not released at that time).

android users were aware of the permission screen that is always shown during the installation, although the majority of them felt that they do not quite understand what the permissions mean.


To summarize, our policy language is complete in the sense of being able to express any policy (relative to a suf.ciently expressive language of access predicates), and also complete in the sense that it can express all policy operators that are the pointwise extensions of functions on the Belnap space.

there are some useful policy composition operations that are not pointwise extensions of functions on the Belnap space.


Because the logs are insu.cient, o.ine re-execution of the production system is actually required during which information.ow-based damage propagation tracking can be done without worrying about the response time constraints.

this approach would face a daunting challenge: we call it the .delity challenge.


Many anomaly detection systems incorporate knowledge into their system about such sweeps, and are explicitly programmed to look for anomalies such as accessing so many ports within a certain period of time.

our approach has no knowledge about sweeps encoded into it.


At .rst, encrypting the data by the owner and then exporting it to the cloud seems to be a good approach.

there is a potential ef.ciency problem with the outsourced encrypted data when the data owner revokes some of theusers accessprivileges.


3.2 Security architecture language An application s security architecture often plays a critical role in achieving its security goal.

designing an appropriate security architecture is non-trivial.


Although the CAM-based solutions are relatively easy to implement, and can exploit .ne grain pipelining in general, high hardware cost and power consumption, as well as high area cost are the main concerns.


This averts the need for transcoding on the server side and enables the server to scale the video.

even scaling takes up computation time and reduces the number of connectionsthe server can accept.


The two neighboring nodes which a priori did not establish a secure link should .nd a path to each other over the graph, in order to do path key identi.cation.

the sparse node degree will increase the path length which will a.ect the communication overhead.


These techniques identify how the transfer of execution to the attacker takes place, allowing the automatic generation of defenses.

as with many technologies, these same techniques can also be used by the attackers.


The research and development communities have addressed this requirement by investigating support of credential-based access control.

most attention has been devoted on the server side of the problem, proposing a variety of models and languages for expressing access control policies at the server, as well as strategies for their evaluation and communication to the client.


In this example, the driver can simply decide whether or not to send a tuple to the DSMS server based on the speed value.

if the privacy policy is changed such that the driver only restricts Role 2 (e.g., users of taxi booking service) users from seeing his/her anchored record and allows Role 1 users (e.g., the traff c authority) to see all his/her data, there will be a problem.


This is because there is virtually no other tra.c on the mail server besides SMTP, whose destinations are mail servers with typically large TTLs.

as we will show in Section 5.4, client .ows are dominantly HTTP.


Similar to Bochs, QEMU [4] is a generic full system emulator.

by using an intermediate language and a technique called dynamic translation, it achieves support for a variety of host and target platforms along with good performance.


A company with several branches may be able to absorb the losses of a single incident at one branch.

if the whole company is a.ected, the damage might be disastrous.


We observe that as expected, the decrease in the genomic privacy of close family members is signi.cantly higher than that of more distant family members.

as we have seen in Section 4, the observation of one (or more) additional family member(s) has often much more impact on the target s privacy than the observation of only one relative.


Unlike the EZ-Online service, no TLS/SSL connection is established between the PC and the EZ-Link server, and data is transmitted through TCP (rather than HTTP) on ports 55155 and 9999, respectively.

tLSv1 is used to secure the communication between the PC and the EasyPay Server.


We believe a moving target based ADS design would, however, make it infeasible for an adversary to craft evasion estimation attacks due to inherent randomness introduced by the mutating feature space.

it is important to identify the right number of features to be employed for detection in di.erent time windows, for optimal performance.


Intermediate solutions are not deployable in real network, unless whole Internet infrastructure is changed.

source end detection is a very challenging task.


In fact, humans perform this function naturally and trivially.

machines cannot understand the subtlety of authentication.


In this case, the average bandwidth consumed per 6 hour period is 77 kilobytes.

this approach may be prohibitive due to short bursts, which required as much as 139 megabytes in a single minute.


Our of.ine analysis shows that the payload for Client Hello can be reliably detected by the monitor.

the time interval between the Key-Exchange message and POST turns out to be so short that it can easily fall through the cracks.


Thus, the monitor code in uml-kernel must disambiguate whether the signal was delivered due to singlestepping or a trap instruction by examining the program counter that the trap occurs at.

the xen-watch implementation did not because the two events are caught by different interrupt handlers.


As mentioned in section 1, there are two basic approaches to providing stronger protection for users privacy in trust negotiation assigning a weaker semantics to users behavior or using additional access control policies to control when to make a response.

no matter what our approach is, privacy protection is not the only concern.


Additionally, an operational separation of duties constraint was speci.ed that an examinee had to leave the BulletinBoard-User role during his/her ExamSession activity.

the veri.cation of the con.dentiality property failed as examinee A was able to wait for completion of examinee B s exam-session and was able to share the ExamPaper through the BulletinBoard.


At this time, an attacker can pose as the laptop and interact with the TLD while using the laptop s ID.

without knowledge of k, the attacker is unable to know what inputs will generate the correct output from the TLD.


There is a large body of work using 2D visualizations to visualize IDS logs, network management systems, and .rewalls [11].

as the amount of information continues to increase, 2D visualizations can also be perceived as cluttered and limited [2].


Interestingly, the regularity test is the only test, other than the corrected conditional entropy test, that achieves lower average scores for all the covert timing channels.

due to the high standard deviation of the regularity test in measuring legitimate tra.c, the regularity test is not an e.ective detection method.


Microsoft Next Generation Secure Computing Base (NGSCB) [7] would support both attestation and sealing.

it requires extensive hardware, operating system, and application modi.cations and appears to have been discontinued.


In theory, these approximations could fail to detect an attack that is able to persistently reuse some or all of the kernel s existing functionality (reminiscent of jump-to-libc style attacks [32]).

we believe that the above approximations will defend against many such attacks because of the di.culty of reusing complete functions for the wrong purpose.


The difficulty here is that many implementations do not send the Time Exceeded message under these circumstances.

those implementations concerned with defense against this attack could easily do so.


Figure 6: Watchdog device beside access point The compromised escort box is useless if not within one wireless hop of the local domain.

if it does show up within one-hop, a watchdog mechanism [10] or its equivalent can effectively detect its existence and monitor all traf.c in-and-out of the escort.


(Note that this self-enforcement mechanism is an extension of ideas originally introduced in [25].)

in some applications, deterrents alone may not be su.cient.


Dual biometric conditions were considered fatiguing and less usable by participants.

these conditions also involved variable, and sometimes long, server delays.


On the one hand, [23, 24, 25] took the approach of devising top-down assumptions about the security policies of other services in the same security domain, i.e., covered by the same certi.cate for a secure channel.

we have the approach of modeling scenarios according to concrete security policies [11].


(The CPU time is much smaller, on the order of 30µs, so that useful work can be performed while waiting for the write out to disk.)

we believe that group operations will be relatively rare and hence the impact on overall program performance even with a sync is very modest.


INTRODUCTION Computer devices with touch panels such as tablet PCs and smart phones become popular.

properties of touch panels are not efficiently used for personal identification, although additional motions of fingers can be obtained from a touch panel.


At NSPR level, we thus observe sequence of method calls from Date and Time category (PR_Now, PR_ExplodeTime) followed by I/O Function category (PR_Write, PR_Close ).

bad web pages never set cookies, rather they retrieve the cookies and send the information over the Internet.


This notion can further be used to include multiple sets of constraints and multiple augmented variables.

care must be taken to ensure that the additional constraints do not cause a satisfiable formula to become unsatisfiable and vice versa.


along the target .ow throughout the training period according to his poisoning strategy.

in the multi-week attack the adversary increases the total amount of cha.


Rumpole: A Flexible Break-glass Access Control Model Srdjan Marinovic Department of Computing Imperial College London, UK Robert Craven Department of Computing Imperial College London, UK Jiefei Ma Department of Computing Imperial College London, UK srdjan@imperial.ac.uk r.craven@imperial.ac.uk j.ma@imperial.ac.uk Naranker Dulay Department of Computing Imperial College London, UK n.dulay@imperial.ac.uk ABSTRACT Access control operates underthe assumptionthatitispossible to correctly encode and predict all subjects needs and rights.

in human-centric pervasive domains, such ashealth care, itishardif notimpossible to encode all emergencies and exceptions, but also to imagine a priori all the permissible requests.


They argue that asymmetric trust relationships are hard to establish, since the parties are exposed to di.erent risks in the case of failure.

with regard to complex SOA that might be based on the dynamic selection of services and service providers  de.ning and enforcing a common trust level is disadvantageous: A symmetric trust relationship between the providers in a federation would require a trust level, which is su.cient for the service with the strongest authentication requirements.


Such a bene.t might be temporary; if more service providers switched to 2word16, this might lead to more such passwords in leaked password sets, in turn providing more training data for attackers.

at least in the short term, this advantage of more obscure policies would remain.


Even though there is some excellent literature available that covers many stealth techniques of computer malware [15, 6], it does not answer the question how their presence looks like from a system state point of view.

we know from the properties of VMI (see Section 2) that a VMI-based IDS can be provided with a complete and untainted view of the system state, thus being able to observe any system activity, whether benign or malicious.


This work could be applied only for a particular case of the multi-synchronous collaboration where all users maintain the same linearization of the collaboration history.

it cannot be applied for the general case of the multisynchronous collaboration where users work on different streams of activity on the shared data corresponding to different linearizations of collaboration history.


5.5 Buffer overreads in other areas of memory We focussed mostly on a stack-based buffer overread for our example, since canaries are currently only widely used to protect the stack and not the heap.

the attack is just as viable on the heap.


Just like a species that draws on a small gene pool can succumb to a single environmental threat, so a ho- mogeneous network is vulnerable to a malicious attack that exploits a single weakness com--,m to all of its components.

in a network in which each critical functionality is provided by a diverse set of protocols and implementa- tions, attacks that focus on a weakness of one such protocol or implementation will not be able to bring down the entire network, even though all elements are not be bulletproof and even if some of components are compromised.


This has the advantage that for storing over long term, records won t be made obsolete from out of date encryption methods.

this allows anyone who gets physical access to the servers storing the records access to the records in readable format.


These modelsassociatetheintended purpose information with a given data element, and access is granted when the access purpose is consistent with thedata element sintendedpurpose.

ashealthcare is such a complexdomaininvolving variousparties withdifferent duties and objectives, the purpose-based access control alone cannot meet all the patient s privacy protection requirements.


For so-called hybrid role mining methods, which take both business information and a direct access-control system UPA as input, we could not .nd a formal problem de.nition in the literature.

several methods for hybrid role mining have been proposed in [3, 10, 19].


Therefore, it cannot enforce that no more than 10 SMS messages are sent per hour [30].

this is a limitation of Android and not Kirin.


At the moment, our tool replaces addition operations, multiplexers and integer comparisons with hand-optimized versions.

the tool o.ers full .exibility; once our modi.ed version of CBMC is able to identify other basic blocks that turn out to be performance bottlenecks, they can easily be replaced by optimized circuits.


E.Hooper@rhul.ac.uk, ehooper@aya.yale.edu Abstract Intrusion detection systems are used to identify suspicious network traf.c.

a high percentage of alerts generated by such systems are liable to be false positives.


They propose to replace the user-provided password with a hash of the original password concatenated with a random value.

they do not present details of how the wallet can de.ne a new password for existing or newly registered accounts.


The scheme allows patients to delegate access rights to their records, and enable remote searches on the encrypted records.

the hierarchical model of the PCE scheme is in.exible.


Both Aho-Corasick and PCRE matching algorithms run DFA transition with an input text, and one can exploit high parallelism by launching multiple threads that share the same execution path.

employing GPU is not free since CPU has to spend its cycles to of.oad the workload to GPU and to get the result back from it.


We infer the presence of bridged structures by examining the server status  7There is of course caveat in using IP address (albeit real or cloaked [13]) for this purpose.

without a better measure of uniqueness at hand, we assume for now that IP addresses are a reasonable measure for uniqueness among members of a single botnet.


= MACRauth (X ' key) KeyConfirmed ' RB := Extkey(W ; X ) key Figure 3: Authenticated Key Agreement Protocol the sender (Alice) would like to be assured that her key is private (and will remain private), but she does not need the key to be shared at the time that she prepares/sends her authenticated-ciphertext.

the recipient (Bob) would like to know that the key he uses for decryption/validation is the same shared private key which was used by Alice.


Ianus s goals are similar to Nooks, HUKO, Gateway in the sense of protecting the kernel from malicious or misbehaving extensions.

ianus does not attempt to physically isolate the kernel from its extensions, but provide a way for them to co-exist.


We believe that the usability of password mechanisms will be improved, and that users will become better educated.

even once this is achieved, there is an additional issue that needs to be addressed: the willingness of users to behave in accordance with proper password practice.


Consequently, the tally cannot be very large and an exhaustive search allows to give the result.

in multi-candidate election schemes the tally can become larger because the encoding of many candidates can- not be reduced and if we want to continue to compute the different results, we have to use an encoding size in O(px [~t), where p is the number of candidates and [£[ is the size of the number of users.


However, 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.

the authorization rules set that corresponds to figure 4 (b) will have one rule that produces r2 and r3 simultaneously.


Another option is to store default ACLs for the various object types in a separate database.

this solution does not allow hierarchical propagation of access rights.


If the attacker can now determine the address of one of those pages at runtime, she can read that page and search for gadgets.

as the last visited pages depend on the past control-.ow, she is either limited to the same n pages each time (in case of invariant control-.ow) or runs the risk of picking a path, which was not executed this time and hence crashes the program.


Even if not necessary, an attacker may still deliberately repeat the same step multiple times to confuse IDSs and/or system administrators.

such variations do not change the corresponding attack strategy.


We found that roughly 81% of applications used WebViews.

upon closer inspection of randomly chosen applications, we found many apps use WebViews for extra functionality such as displaying company policies or advertisements.


These points had not been raised by students during any of the lectures or laboratory sessions.

it became very evident during the formative feedback sessions, which gave teaching staff ample time to correct these misconceptions and gave grounds for expounding on these very important concepts.


Originally, Xen 1.0 contained device driver code and provided shared device access.

device drivers are one of the most troublesome aspects of commodity operating system Chou et al.


After all, a cardiologist is a kind of physician.

as noted in [10], there may be tasks that a physician frequently performs but that are  Figure 3: Implementation of wrappers as services that a reference monitor can use to resolve con.icts or .ll gaps.


The use of cryptographic techniques in these systems range from the assumption that all incoming data is already encrypted, to central architecture elements that de.ne the system.

none of these systems attempt to achieve the storage ef.ciency that is possible through deduplication.


They proposed a recipient recommender based on .le similarity, which has been described in Section 6.1.

they did not evaluate their recommender in [3].


EXPLOIT HIJACKING Finding software .aws and turning them into exploits is not a trivial task, as it requires a great deal of knowledge and creativity.

manually crafting anew exploit from an existing one is signi.cantly easier and has even been used by the creators of infamous Internet worms such as Blaster and Slammer.


observe that verifying that AuthzTRM holds at the time of request will allow the subject access to objects that were added during the time between RT and request .


This construction should be considered insecure as elements except for the password are public, hence an adversary can launch an of.ine attack on the low-entropy secret, the password.

dolev-Yao abstractions that model the password as a fresh nonce will not recognize this attack since n there is not formal deduction of p w from the accumulated terms.


between building an accurate model of the power consumption, which requires more key bits to be considered in a single time, and the computational complexity involved in computing a power hypothesis for every possible value which may be taken by the key portion.

since attacking one key portion is performed independently from attacking the others, the attacker is free to divide the whole key in portions that are small enough to be processed.


Validating access control safety in its most general sense is undecidable [6].

there are restricted and abstract models of access control such as [11, 2], where some properties can be validated e.ciently.


RELATED WORK The problems of role completeness and role management e.ciency resulting from the role engineering process has been evident from the earliest papers on the subject [4].

only recently have researchers started formalizing the area of role-set optimality.


Though they differ in the proposed concepts, the general structure remains the same for the SLA: information on the parties involved, the SLA parameters, the resource metrics used to compute the SLA parameters, the algorithm to compute the SLA parameters, the service level objectives (SLO), and the appropriate actions to be taken in case of a violation of the agreement (aka breach management).

classic QoS parameters that are used to describe the relationships among common web services are not suf.cient in a generic cloud environment.


Several approaches have been proposed that mostly use data mining techniques to discover roles.

most of them do not consider the existing roles and try to de.ne everything from scratch, which is not acceptable for organizations that already have an RBAC system in place.


how to get to the beginning of a function and where the frame pointer is stored.

since we randomized the code this information is no longer valid.


The above graph partitioning problem is NP-complete.

many algorithms have been developed to .nd reasonably good partitioning (e.g., [15], [14]).


Using the transparency technique, AdSplit allows users to see the advertisement through the transparent region in the application activity.

the use of the transparency technique can be problematic.


The constructions of [35, 36] proceed by turning a (t, n) polynomial secret sharing into a (t, t) additive secret sharing by .rst selecting a pool of at least t participants.

if only one of these fails to provide a valid contribution to the signing process, the whole protocol must be restarted from scratch.


This is how the revocation problem is usually addressed in the traditional system [2, 3, 4].

this does not work well in the identity based encryption setting.


scheme Bob might receive a private key for the policy year=2007 AND dept-review , which would allow him to see all comments from this current year.

in this setting it is important that Bob should not be able to view comments written about his own department.


5.3 Session Management In the above discussion, we focused on minimizing the information released by the client in response to a request from a server.

web-based information systems typically support a navigational access to resources.


, 0) is in the span of rows of M indexed by I.

this means that there exist constants {.i} i.I in Zp such that for any valid shares {.i = (Mv )i}of a ( i.I secret s according to ., it is true that: i.I .i.i = s. Additionally, it has been proved in [5] that the constants {.i}can be found in time polynomial in the size of the i.I share-generating matrix M. for unauthorized sets S' no such constants {.i} exist.


WebView has an option named javascriptenable,with False being its default value; namely, by default, WebView does not execute any JavaScript code.

this option can be easily set to True by the application, and after that, JavaScript code, embedded in the web page or injected by the application, can be executed.


If a program stays in the sandbox fora long timewithoutperforminga context switch (for example, in computationally intensive programs), then the runtime overhead should be small; the overhead would be similar to the overhead of NaCl, which has been reported to incur 5% of overhead on SPEC2000.

if a program makes frequent context switches between Java and native code, then there should be a signi.cant runtime overhead.


The loadscales proportionally withmore members.

with Pre.Sec, a particular node, say RouteViews 2, would make 209 pre.x queries (due to pre.xes with a new origin: origin not seen ) and 1,949 subpre.x queries (due to new pre.xes seen: pre.x not seen )to the overlay.


Marc Joye Thomson R&D, Security Competence Center Cesson-Sévigné, France marc.joye@thomson.net should be conceivable that buyers can make their choices and shop on Internet without risking to be pro.led.

it is understandable that, in some situations, there may be a need to be able to revoke the anonymity; for example in the case of a legal dispute while keeping the content private.


complete roles that are wrong or missing.

since these are exactly the patterns the algorithms are searching for, they would have no chance to discriminate them from valid structures (if there is no side information from other sources) and this in turn would not allow for a comparison of the methods.


The author in [9] also collected system call sequences for various processes and divided them into di.erent groups of system calls that belong to benign processes, malicious processes or code injected processes.

he did not do any empirical evaluation to study the e.cacy of immune systems for malware detection.


For example, GPS data from personal devices can be used for improving environmental e.ciency of citizen mobility by generating e.ciency scores.

it can also be used to spy out whether someone is at home for planning a burglary.


Given that a signi.cant proportion of traditional malware abuses this mechanism and that mobile devices generally do not take advantage of this capability, we believe that this is a .rst strong step in preventing kernel compromise.

we recognize that deploying Airmid on real systems may require additional hardening.


If brute force attackers do not know the correct password, they can login with a probability of five percent when they reach the correct password among many trials.

there is a problem that the accuracy of characteristics on flick input is unstable since users freely make their postures when they use their smart phones.


Of course, these operational semantics may be regarded as acceptable in certain situations.

if we assume that it is desirable for a hierarchy operation to preserve administrative scope, then it is necessary to impose some additional conditions that must be satis.ed if the operation is to succeed.


{1,...,f}there is a polynomial time semantic security adversary B for E such that Pr[wj ,E] = qj ] =SS Adv[B(3) To see why, notice that when all bits at position j in C are 1then Adoes not have sk[j,0].

if Pr[wj qj]is = `´ non-negligible then Ais able to distinguish Eenc pk[j,0], 0 `´ from Eenc pk[j,0],m , which breaks semantic security of E. A similar argument applies when all bits at position j are 0.


Most importantly, simulation allows us to analyze the effectiveness of various solutions in different settings with limited user effort.

user study may better re.ect the real-world effectiveness of our system,butthestudyismuch moreexpensiveto carriedoutthansimulation.


The transformation does not a.ect the features of our proposed KP-ABE scheme, i.e., constant-size ciphertexts and fast decryption.

utilizing the new proof methods proposed by Lewko and Waters [29] recently, it may allow our proposed KP-ABE scheme unrestricted use of attribute names.


[17] implement nested virtualization support for KVM.

in these systems, KVM, particularly the (lowestlevel) L0 hypervisor, is still tightly integrated with the host (including the sharing of the same address space).


The authentication part locates the watermark distortions .rst, followed by the locating of altered regions on the image.

in this work, we exploit the embedding mechanism and hence are able to retrieve the embedded secret sequence, upon which the digital image could be altered and thus an attacker can succeed in fooling the detector.


Similar to our setting,individuals obtaintheirgenomes and allowauthorized parties(e.g.,doctors) to rungenetic tests such that only test results aredisclosedto one orbothparties.

[6]only addresses the issue of designing cryptographic protocols, and does not deal with real-world issues.


In this case, one can notice that integrating the PUF inside the HSM will prevent all the key stealing attacks listed in Table 2.

an attacker with full access could still use the HSM to perform malicious actions such as signing forged message.


We found that HTTP is the most common protocol used among malware families.

some malware families do not completely rely on HTTP.


By re-implementing the EarlyBird [26] in a distributed manner, they use the content block .ngerprint to .nd popular contents, and then use address dispersion to identify worms.

such signatures may not be accurate and cannot work against even simple polymorhphic worms.


To pro.t from their data while honoring the privacy of their customers, social networking services share anonymized social network datasets, where, for example, identities of users are removed from the social network graph.

by using external information such as a reference social graph (from the same network or another network with similar users), researchers have shown how such datasets can be de-anonymized.


Assuming the interfaces are secure by design and untrusted input is su.ciently sanitised, adding interface code to the TCB could increase the overall trustworthiness of a system.

we propose to add another parameter to the evaluation of the TCB: hardware separation.


Signature based detection aims to detect intrusions or attacks from known intrusive patterns.

anomaly based detection looks for attacks based on deviations from established pro.les or signatures of normal activities.


It can t tell from the keys whether or not a given VOBU is a point of variation or not.

the content creator, assigns the keys such that they correspond to the inner code .


In addition to such data management solutions as Hippocratic Databases, researchers [3, 2] have also studied how to regulate access control exceptions in healthcare using advanced policy technologies.

none of the above work studies how to employanalytical techniques to assist individual patients on access control decisions.


Because of this behavior, data carving will continue to be necessary when performing the forensic analysis of an Ext4 file system.

as the Ext4 block allocation schemes do their best to prevent file fragmentation, data carving may be more successful if it is initiated soon after the original file has been deleted.


The reason we designed and implemented MOBIKEv2 is that MOBIKEv2 is an extension of MOBIKE and leaves IKEv2 and the kernel implementations of IPsec unchanged.

the BEET mode requires the BEET mode to be implemented in the kernel, and IKEv2 to consider this new mode.


Moreover, even when the controlling site has been taken down, existing puppets will continue to perform an attack the attack will only subside once all puppet browsers have been pointed elsewhere, which is likely to be in the order of 10-60 minutes, based on the viewing time estimates of Section 2.1.1.

as shownin[33], we have beenable to circumvent the default behavior of browsers that set referrer information, making puppetnet attacks more di.cult to .lter and trace.


[4] construct anonymous credentials that support delegation.

the algorithms in this setting are considerably more expensive, and the computational costs of creating a presentation proof and verifying it are still signi.cantly greater than in U-Prove.


Unauthorized Origin Crossing on Mobile Platforms: Threats and Mitigation Rui Wang Luyi Xing Microsoft Research Indiana University ruiwan@microsoft.com luyixing@indiana.edu ABSTRACT With the progress in mobile computing, web services are increasingly delivered to their users through mobile apps, instead of web browsers.

unlike the browser, which enforces origin-based security policies to mediate the interactions between the web content from different sources, today s mobile OSes do not have a comparable security mechanism to control the crossorigin communications between apps, as well as those between an app and the web.


The usability of our clickable CAPTCHAs is similar to the ASIRRA and BotBarrier work.

we believe our clickable CAPTCHAs enjoy two critical technical advantages over existing image-based approaches.


Over-.tting results from representations with surplus capacity, while insu.cient capacity will lead to hypotheses that fail to capture the problem s underlying complexity.

we speculate that overly .exible learners may be easier to attack with reduced adversarial capabilities.


We are con.dent that, if more data were available to us, SpiderWeb would have been able to detect also these URLs as malicious.

spiderWeb detected 778 URLs as malicious that went undetected by the AV vendor.


Limited Knowledge: For a successful UFDI attack, an attacker needs to know the grid topology (i.e., the connectivity among the buses) and the electrical parameters of the transmission lines.

gathering this knowledge is not trivial [3].


At a high level, a privacy violation occurs when an app releases sensitive data to a remote party in a way neither expected nor desired by the user.

encoding user preference and expectations inside automated analysis is dif.cult.


n PLdec = `X j * n PLj * (1 - PL)n-j ´/n .

(1)j j=n-k+1 the network packet losses usually behave as a bursty process.


implemented and compared ECC and RSA on Atmel ATmega128 in assembly [15].

it is not clear how well their implementation can be integrated into sensor network applications.


Of course, these checks require significant effort on the part of the user and will likely be carried out only by the more technically savvy (and more paranoid) users.

even occasional monitoring for covert attacks by Facebook would be sufficient to discourage them generally, since news of such attacks would be a public relations nightmare and would additionally possibly carry legal liability.


The 802.11 standards allow the realization of economic Wireless LANs that support data rates anywhere from 1Mbps to 54 Mbps based on the distance to the access point.

802.11 access points can cover areas of only a few thousand square meters, making them suitable for enterprise networks and public hot-spots such as hotels, coffee saps, and airports.


Chuan Yue University of Colorado Colorado Springs Department of Computer Science Colorado Springs, CO 80918, USA cyue@uccs.edu Password security heavily depends on creating strong passwords and protecting them from being stolen.

researchers have demonstrated that strong passwords that are su.ciently long, random, and hard to crack by attackers are often di.cult to remember by users [5, 12, 22, 24, 36].


Thanks to the homomorphic and the non-interactive properties, the element-wise encryption scheme is extensively used in the .eld of s.p.e.d..

the employment of a probabilistic homomorphic cryptosystem will make the element-wise encryption scheme cause serious ciphertext expansion, especially in the case of image processing in the encrypted domain.


This, coupled with the possibility of zero-day threats that may provide little or no warning for creating these emulated behaviors, may leave wide addresses monitoring systems unable to identify the important threat characteristics.

honeypot systems provide detailed insight into new threats by monitoring behavior in a controlled environment [5, 34].


The identi.ers are embedded in instructions and cannot appear in the rest of the code.

this property cannot be guaranteed without inspecting the whole program.


In the context of publish-subscribe systems, there are many solutions that address privacy and security issues [6, 19, 23].

the state-of-the-art techniques are mainly based on centralised solutions that cannot be applied to opportunistic networks, where each node may serve as publisher, broker, and subscriber.


The Flash player is responsible for enforcing this security measure.

there are cases where access to data in a different domain is required.


This will allow us to prevent malicious schemes from entering the ecosystem, such as an IA developer creating a keystroke Measurement that also functions as a keylogger.

as running the Oracle or accepting its recommendations are not necessary steps in order to use Itus, this approach allows for researchers to freely experiment with IA, and for IA developers to distribute standalone extensions to Itus.


Con.ict resolution based on the speci.city of authorization assumes the existence of an object oriented hierarchy relating the targeting objects and subjects.


Using a different AIK for each relying party prevents the relying parties from tracking the client across sites.

since all of the AIKs are certi.ed by the same EK, they can all be bound to a single installation of MiniVisor, preventing an attacker from using a separate MiniVisor for each destination.


Similar to [32], we notice that our construction can be extended to the chosen-ciphertext model by applying the technique of using simulation-sound NIZK proofs to achieve chosenciphertext security [31].

in Section 9 we describe how our delegation mechanism can be used with the techniques of Cannetti, Halevi, and Katz [16] to achieve a much more e.cient CCA-2 system.


Alice routinely uses the supercomputer as part of her job as an astrophysicist, and she knows that she has the needed permissions to satisfy the security policy.

what Alice does not know is that her bosses have become displeased with her, and they have scheduled for her to be .red on Wednesday.


For e.g the AP can share information related to User Authentication or pro.le information based on some revenue-sharing mechanism with the other members of the Circle of Trust (CoT).

there may be other information types which are su.ciently generic and applicable across di.erent usages, yet semantically di.erent from or not easily covered by the above three standardized types.


Clearly, context-insensitive sanitization o.ers better protection than no sanitization strategy.

context-sensitive sanitization has full protection whether the context-inference is performed dynamically or as in our static type inference approach.


However, for .xed strings, there are algorithms for matching sets of strings simultaneously.

consequently, while Snort s default engine still works iteratively, there has been recent work to replace it with a set-wise matcher [8, 12].1 regular expressions give us setwise matching for free: by using the union operator on the individual patterns, we get a new regular expression which effectively combines all of them.


Di.erent types of semantic attestation solutions may concern di.erent properties of software.

the integrity of a program is the basis for all di.erent solutions.


there is reason for concern even if we were to witness the development of a truly ideal CAPTCHA one that cannot be beaten using automated methods and which does not pose any usability problems.


We conclude that most of index page is designed securely.

some of the portal site is not secure against the ARP poisoning attack.


In fact, in order for the jammer to be more e.ective, it needs to operate at a relatively higher power level.

a jammer using higher power will further decrease the PDR value and increase the SS measurement, thus pushing the resulting (PDR, S S) pair further towards the upper left corner, making it more distinct the benign-region.


Other systems adopt a simple solution, that is, stopping the evaluation of the policy and returning an error message (usually a Deny is .nally returned to the access requester).

such a simple solution is not always the best.


In a device based DRM scheme, such as OMA (Open Mobile Alliance) DRM [1], the security comes from enforcing usage of compliant players and unique global device identi.ers.

this kind of DRM schemes is constrained by its in.exibility, especially in the mobile Internet.


Since certi.cateless cryptography was introduced by Al-Ryiami and Paterson [1], numerous certi.cateless encryption and signature schemes, and variants thereof, have been proposed.

the equivalent of public-key signcryption has not been considered in the certi.cateless setting.


8.CONCLUSION Traf.c watermarkingis importanttomany network security and privacyapplications, because it cancorrelatenetwork .ows observedat different locations quicklyandaccurately.

the state-ofthe-art timing-basedtraf.c watermarks cannot only survive adversarialnetwork conditions but alsoevadeexistingdetection method s. we showin this paperforthe .rst time that all ofthem will disturb the intrinsic timingfeaturesinTCP .ows andpropose a novel system, BACKLIT,to detectthem.


Due to the good contact to some of the development teams, we learned that countermeasures were taken.

not all existing attack vectors were considered.


The signature size of our scheme is much smaller than most previous signatures based on one-way functions; and the veri.cation is also more e.cient.

our public keys are larger than most previous systems, and the time to generate signatures is also higher.


This includes box shadows, rounded borders, and background images.

our investigation showed that typical scrollbar background images are requested directly after page-load.


The severity of phishing is recognized since the mid-1990 s and a considerable amount of attention has been devoted to the topic.

as we will show in Section 2, currently deployed or proposed countermeasures are either incomplete, cumbersome for the user, or incompatible with standard browser technology.


This countermeasure is very e.ective and by far the most secure.

it would require a lot of administration e.ort for enterprises.


In these systems, installation cost of hypervisors is not a big concern because they are installed to realize central management mechanism.

when we encrypt guest OS images, background encryption has a possibility to reduce initial deployment cost of each encrypted guest OS by skipping manual encryption steps for existing OS images or avoiding OS installation with overhead of cryptographic computation.


We found very few instances of pronouns as objects.

we did find that ambiguous terms (e.g., list , name , record ) occurred 21.5% in all of the ACRs.


We observe that in rare cases some nodes experience small Nhd values, which canbe causedbyimperfect synchronization among devices or channel fading.

this can be solved by increasing the length of each minislot.


With optional additional round trip The protocol in Figure 3 has the disadvantage over the one in Figure 2 of requiring an extra two messages (i.e., an extra round trip).

the purpose of adding the extra messages is that the result is that messages 1, 2, and 3 are all small enough that they would not require fragmentation.


Note that duplicate records in the original set might be mapped to different records in the encrypted space due to the randomly generated additional dimension k+2.

this query transformation method guarantees all of such records are still exactly found in the encrypted space.


This is reasonable information for a human user.

achieving machine-readability requires that measures are defined even in a more detailed manner.


The adaptation mechanism improved the performance of the system on average.

it is observed that the error rates for the passwords 3, 5, and 9 were increased slightly by the adaptation mechanism.


In a free and democratic society, it is vital that the public to have access to information and that the media have the right to inform the public through print, radio, television or other electronic means such as Web sites.

these rights cannot be left wholly unfettered as they are not absolute rights, absent of any limits or controls.


establish a new shared key with the target, using the devices in the EstablishedSet as intermediary devices (line 5).

establishing a new key to the target device is only necessary if the RequestingSet is non-empty or the device is the source device of the query (line 6).


These results show that small deployments can be trivially defeated, requiring larger deployments for decoy routing to be successful.

several of our con.rmation attacks still work, even against very large deployments.


This, of course, might have the e.ect that privacy unaware users cannot bene.t of the privacy protection mechanism.

we could have the privacy mode as the default and fallback to the normal mode when privacy mode is not applicable.


it has to be kept in mind that database forensic methods can recover deleted keys from the database, thus additional measures have to be taken.


We discuss more details on how to compute pairing e.ciently later in Section 5.1.3.

a sequential aggregate signature scheme [28] is based on homomorphic trapdoor permutations, such as RSA.


The MSIV can be closed to isolate the steam generator from the rest of the system in case of a problem with the steam containment system, such as a leak or break.

closing the MSIV also prevents the secondary system from providing adequate cooling to the primary system.


Some controllers also provide hardware support for cryptographic algorithms [23].

those protection mechanisms usu ally are implemented in a low-cost manner and can often be broken without a high e.ort [24].


2.2 Healthcare Information Systems and Patient Monitoring Nowadays, in healthcare domain, information systems containing patients information are typically quite isolated.

in practice, patients change often their healthcare providers.


However, though these techniques perform well for PC malware, they are not built to handle the nominal categorical data available from mobile applications.

multiple Correspondence Analysis (MCA) [1] is designed to analyze the correlation between multiple categorical attributes.


If at some point in the execution of F two values Ri = Ri 1 are found such that ti = H0(Ri)= H0(Ri 1), then clearly at least one collision must have occurred in H0.

all response values of H0 are chosen uniformly at random from {0,1}l0 , and since there are at most qH +NqS queries to H0, the probability that at least one collision occurs is at most ((qH + NqS)(qH + NqS +1)/2)/2l0 = (qH + NqS +1)2/2l0 .


a targetedpolicyschemeis where all unde.ned requests are allowed and the policy only consists of deny rules.


The role of the bitmap in MIP is similar to the role of ID tables in MCFI.

a MIP module s bitmap is never updated during runtime and is made readonly.


Indeed, there have been various works in this area, but most of the have solved the problem by adding new elements to the Attribute statements [12] or de.ning new pro.les [4].

delegation comes naturally to Dependent Assertions, wherein the AP could generate the Dependent Assertion with two or more Subject Con.rmation methods.


Authenticated Delegation List: Toreducethecostofsignaturecreationandveri.cationrequiredbysimpledelegationattestations,anorganizationcancreateasinglelistofallofitsdelegationsandsignthatlist.Wecallsuchalistanauthenticated delegation list.Moreexplicitlyanauthenticateddelegationlistisoftheform [(C,xlIjl,Fc(xlIjl)), (C,x2Ij2,Fc(x2Ij2)), , (C,xsIjs,Fc(xsIjs))] c whereV(C)={xlIjl,,xsIjs}.


Encryption schemes with strong security properties will guarantee that the patient s privacy is protected (assuming that the patient stores the key safely; see section 3.1 for discussion).

adherence to a simple encryption scheme can interfere with the desired functionality of health record systems.


We note that a community structure can also originate to legitimate activities, for example, due to tourists calling hotlines in a popular resort or companies communicating with foreign branches.

as we shall see in Section 5, this heuristic can help successfully isolate a large number of popular fraud activities from millions of phone calls.


Antivirus products, probably the most widely deployed security technology, attempt to do this.

they primarily rely on a blacklisting approach: only programs matching Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for pro.t or commercial advantage and that copies bear this notice and the full citation on the .rst page.


In summary, the experiments show that two identical PUF circuits on two di.erent FPGAs produce a di.erent output bit with a probability of 46.15% on average.

multiple measurements on the same chip are di.erent only with 0.48% probability (i.e., 0.6 bits out of 128) even in the worst-case environmental change.


Even when requiring a PIN to unlock the device, an attacker that has root permissions (root attacker ) can assign private keys to other applications on the same device by renaming the (possibly encrypted) .les as shown in Section 8.3 and discussed above.

the root attacker has to decrypt the private key entries to be able to use them outside of the device.


In the current prototype implementation, we do not solve this infrequent case.

re-assembling the fragments and extracting this information is quite straightforward if desired.


0 In this paper, we consider the situation where smart devices (excluding smart meters) receive potentially harmful inputs from ostensibly legitimate sources.We do not consider smart meters, since they are usually located outside of the household, and they are physically insecure.

a mal-functioning smart meter will not directly threat household safety.


A third challenge is that the execution of a SODA must be isolated from normal app code, and the SODA must run in a monitored environment where it can not cause side e.ects.

since we want to access private data in the SODA (under the trusted component s supervision), we must devise a way to let the SODA easily access sensitive information while preventing it from leaking the information to untrusted components.


If A and B are highly correlated, most of the information about B is communicated through A and H(B|A) is small.

if pA and pB (which respectively represent the probability mass functions of A ad B) are quite di.erent then H(B|A)assumes a high value.1 To identify the order of correlation presence in the IDS scoring random process, we de.ne a Markov chain based stochastic model as follows: Let the score at discrete time instance n represent the realization of a random variable derived from a stochastic process Xn.


While security is not the primary goal in most cases, these operating systems often offer features that aim to enhance security by protecting customer data on hosts, reducing the amount of trusted code, etc.

these operating system projects do not focus on the bigger picture that includes cloud services.


The resulting SecureUML break-glass policies can then be transformed into XACML.

this approach does not consider break-glass decisions in connection with dynamic mutual exclusion or binding constraints.


The violation of privacy caused by the disclosed personal data, which means, the less data disclosure, the less risky of privacy threats.

figure 1 Architecture of the Proposed System for the sake of security protection, the features of multimedia surveillance facilitate the collection of individual information and increase the risk of misuse and abuse of surveillance data.


It is important to note that we are not concerned with establishing an apriori necessarily complete set of categories for access control, and we also only give a descriptive, language-based account of categories.

the categories that may be used in our meta-model can be arbitrarily complex (e.g., by combining subcategories) and multiple subcategories can be derived from any number of (super-)categories.


The protocol, however, can be easily extended to make use of already established claim types such as these proposed in [24, 18, 11], and [10].

some of these types appear to be too complex and therefore not well-suited for Web 2.0-style implementations, and all these types lack the ability to specify required parameter values in claims; thus they may be unable to satisfy complex use cases such as these discussed in [8].


As shown in Figure7, TMI-based authorization has acceptable overhead when applied to servers written to use STM techniques; TMI-based enforcementcanevenimprovethe performanceofsuch software.

the No-STM and STM-only columns show that simply using DSTM2 for concurrency control results in a very substantial performance overhead.


DBTaint provides a cross-application .ne-grained taint tracking platform by tainting database records, which is similar to SilverLine s approach of adding taints to database rows.

dBtaint does not de.ne speci.c security checks, and it also requires a modi.ed language runtime.


[15], by testing the use of multiple passwords in the new system.

we have not split the creation of passwords across multiple sessions, which could be done in the future, to study the effect of retroactive interference.


In the example, we show two RegEx signatures and based on these two RegEx signatures, we extract four ranges [a-zA-Z], [a-z], [a-f] and [g-z].In Figure 6, we previously stored all the nine possible length combinations.

not all the nine combinations are needed to represent the RegEx signatures set in this example, so number of length combinations to be queried and stored can be reduced.


For example, 627 different malicious apps have the same name The App .

even with a similarity threshold of 0.7, the number of clusters for benign apps is only 20% lesser than the number of apps.


An intuitive approach is to utilize previously proposed anonymity measuring solutions for wireless networking environments.

in wireless ad-hoc environments, it is di.cult to prede.ne the probability assignment of the transmission pattern for each mobile station.


As a consequence, ROP in its general form becomes impossible (e.g., the attacker cannot make use of a stack pivot gadget to make the switch the stack pointer to its ROP payload, because no legitimate function is likely to perform a stack pivot).

return-to-libc-type attacks (but with kernel functions) may remain possible.


However, providing a robust level of security while at 3In practice, S would generate a set of challenges for each administrator.

including that detail in our protocol de.nition would complicate the notation, and we refer toasingle Ci instead.


Cross-origin communication in Flash adheres to the sameorigin policy.

this is not a restriction, since Flash also supports cross-origin communication via cross-origin resource sharing.


there exist some exceptional cases as explained in [15, Section 2].

exceptional cases can only occur in scalar multiplication if the base point P does not have a prime order, which normally never happens in an ECDH protocol for sensor nodes.


These incidents generate an excruciating cost for the and uphold the confidentiality, integrity and non-repudiation of enterprises, ranging from the loss of revenue to the damage of shared resources and information.


We used an interpolation frequency of 100 Hz.

we have introduced one more module called Piecewise Linear Approximation (PLA) just before the Cycle Length Estimation module of .gure 5, as shown in .gure 8.


Random dynamic voltage and frequency scaling(RDVFS) as a countermeasure was proposed in [17].

no direct evaluation against side-channel attacks was reported there.


We emphasize that the protocol in [14], for smaller domain values (i.e., 0 = x < 2m), is not secure since the intermediate decrypted values are not uniformly random in ZN .

the general solution (referred to as the BITREP gate) proposed in [14], for x .


The adversary can trivially prevent any party X from publishing its signing key by preventing the delivery of even one of the end messages.


Figure 4 shows the STREAM benchmark results where about 3 to 4% of performance overhead were observed when ATRA is in e.ect.

aTRA without TLB .ushing feature (although the attack becomes ine.ective) showed nearly identical performance as the case without ATRA.


In this way, users are forced to compare phrases with at least one other user and actively choose which phrase matches among them.

to prevent attacks, all users need to validate that they all have the same word phrase.


These work allow a partial order to be established on different network con.gurations based on their relative security.

the treatment of many aspects of security is still qualitative in nature.


Alternatively, we can enforce control.ow integrity (CFI) [3, 39] on KVM inside the isolation runtime to provide a stronger security guarantee, especially in eliminating recent return-oriented programming (ROP)based code-reuse attacks [8].

one challenge behind CFI enforcement is the lack of an accurate and complete points-to analysis tool that could be readily applied to KVM.


Even if a child transaction commits, its parent may choose to abort, and that in turn requires the child transaction tentative commit to be undone.

abort of a child transaction does not require the parent transaction to be aborted.


For example, to determine the presence of a security software S, an inventorying de.nition is authored which requires ST to look for an entry in the con.guration .le which is placed when S is installed.

sometimes such software speci.c entries are not deleted while uninstalling a software (e.g.


In the cluster hierarchy in Figure 1, the rAcc permission shows up only in the upper part of the hierarchy.

we know that it also occurs almost as often with the rTrans and cdAcc permissions aggregated in the lower part.


Peng's OT Compression [2005] is the best method at present.

it adopts a fixed and implicit order of progressive mesh refinement, so as not to explicitly encode the order of mesh refinement.


The described system does not provide 100% success, there is always a (slim) chance for unsolicited messages to reach the target.

we believe the proposed method improves the current situation.


In order to calculate the probabilities that a certain player can transmit a certain value, we con 1 = 1 = 1 steganographic communication more practical.

ef.cient strategy learning with a small number of games as training data would then be a far greater challenge.


3An automatic binding-time analysis is in the .nal stages of implementation (as can be guessed from the screenshot in Appendix D) and it will hopefully be able to annotate our interpreter automatically.

it is acceptable to perform the BTA by hand, as the annotation only has to be generated once and it is independent of the database as well as the access control policy.


b: q(a,b)=T Thus when the input pair (i1,i2) is in our privacy relation R, then given PM(o|i1) there is an interval of allowable values for PM(o|i2).

the endpoints of the interval may or may not be allowable values.


4.3 Theoretical Analysis: Correctness andSoundness It is easy to see that without knowing the circuit x, V conducts all the PCP checks (except the linearity tests, since the commitment has provided linearity tests already) for C. The correctness and soundness of this scheme follows directly from the linear PCP scheme.

it should be noted that V has access to the pair ((r1||R1) + a0(r0||R0), s1 +  Table 1: Comparison of Commitment Protocols Ishai et al.


If the attacker has the message used to deliver the key, he/she can recover the pairwise key.

the related sensors can establish a new key with a new round of path key establishment once the compromise is detected.


due to distorted characters looking like each other.

it is not necessarily the case in schemes where English words are used.


We have made similar assumptions about the underlying infrastructure.

we have not explicitly stated our trust assumptions.


To date, much of the emphasis on protecting sensor networks has focused on key management and secure routing.

as sensors become more capable and ubiquitous, the need for more .ne-grained control over their resources grows.


Static analysis is used to analyze binary contents and to generate detection signatures.

panda Research [1] reported that about 79% of malware found in 2007 is packed, so static analysis has clear limitations [18].


One way to avoid this is to lock the target area and prevent the guest OS from accessing it while the hypervisor is encrypting.

using locks may interfere with the guest OS operations.


Many of these students had a good level of knowledge about their computer and how it worked.

not all students needed or wanted to bring their own computers to campus, nor could they necessarily afford them.


INTRODUCTION Storage outsourcing is a growing industry that shields storage users from the burden of in-house infrastructure maintenance, and o.ers economies of scale.

due to concerns over data privacy, many potential cloud users have yet to join the cloud, and many are for the most part putting only their less sensitive data in the cloud [8].


Note that the AM does not completely encode all the UAS elements or the derived relations as is done by the DB and DRB approaches, respectively.

this approach can be used to identify undesirable UAS elements (thus indicating undesirable hierarchy design) by querying whether the undesirable set of roles are allowed by the hybrid hierarchy to be activated in a single session.


3.3 Enforcement Code The enforcement code generated by our enforcement engine is driven entirely by the security policy specification, and is thus entirely application-specific.

there are two major axis of freedom for the implementation of this code that has a strong impact on its performance.


Although we could consider various constraints related to users, sessions, and roles investigated in [14], we focus attention on the constraints on ca 1 When implementing these steps, steps (1) and (2) are usually regarded as a single step, because in general the capability consists of an object identi.er and permissions for this object.

in our model, to categorize the types of delegation we divide this creation of capability into these two steps.


In fact, it is important to ensure that the correct execution of the sample does not cause any damage to other external hosts, for instance in the context of self-propagation attempts.

these concerns go beyond the containment issue and relate directly to the quality of the analysis itself.


In particular, Panorama and TaintDroid do not allow for the dynamic speci.cation of data security policies.

they are related as their precision can be improved when coupling their taint tracking features with more precise, general purpose policy management systems such as Constroid.


More precisely, in the event that the current rendezvous point is taken down, the botmasters simply have to register the next domain in the domain list to regain control of their botnet.

to the defender s advantage, domain .ux opens up the possibilityof sinkholing(or "hijacking")abotnet,byregisteringan available domain that is generated by the botnet s DGAs and returningan answerthatisavalidC&C response(tokeepbotsfrom switching over to the next domain in the domain list).


By setting 6 Mbps (minimum data rate in DSRC) to Equation (1), we now can derive the upper bound of ad content size xwith respect to interval r. Figure 4 shows that the upper bound of x, according to rin this 100-neighbor scenario.

in the case of onion voucher based model, due to three-way handshake process among vehicles, the resulting system throughput of the above scenario is 1000 msg/sec ×{[100 r cars ×(120+x) bytes/msg]+[100 ×100 cars ×112 bytes/msg]+ [100 ×100 cars ×280 bytes/msg]} =8 ·{(120 + x) + (392 ×102)}/(r·10) Mbps.


For example, we could derive such a shared key by using a customer-chosen PIN code that is utilized in PG&E s system such that only a third party that knows the PIN can access the corresponding customer s energy usage data [12].

we should note that in our scheme, such a key is not used for data con.dentiality, authentication, or access control.


Implementation Comparison: To detect a TCP scanning attack with an OpenFlow application, we need to check whether each TCP session is successful at the application layer.

this check requires that the application manages each TCP .ow making it vulnerable to control .ow saturation attacks.


This remapping essentially augments the interpreter to perform simple run-time analysis for further safety.

while language constructs constrain what loaded code executes, there remain certain built-in functions that provide functionality outside of what can be expressed within our language constraints.


In other words, the ISP s edge routers only forward the SMTP tra.c from some designated IP addresses to the outside.

spammers have easily evaded such simple SMTP port blocking mechanisms.


During the remaining time in this session u can no longer act as a privilege user.So if there is a section of articles in the DL which is only available to privilege users then u can not access those articles anymore.


Unfortunately, we did not .nd any publicly available real query sets to use in our experiments.

we argue that an adversary might not have any control to the set of known queries.


Clearly, a proactive approach is preferable for both unknown and known infection vectors.

scanning a web site proactively with online analyzer systems [12 14] is computationally very expensive, and would introduce delays up to multiple seconds per web site.