This makes RSS-based user authentication schemes su.er poor performance when two legitimate users (but physically separated) present the similar signal .ngerprints.

we observe that the authentication accuracy for RSS-based method degrades to only around 0.64 as shown in Figure 9.


Considering security for IMDs is necessary because: (1) they deal with sensitive patient information, (2) laws such as the Health Insurance Portability and Accountability Act (HIPAA) [14], mandate it, and (3) security attacks can have serious safety consequences for the patients.

a malicious entity can now easily suppress legitimate information and introduce bogus information between the devices and the middleware, leading to untimely or unwanted actuation or loss of privacy.


For example, if we are shopping at Amazon, the process of choosing things to put in our shopping basket does not raise any security issues we do not need the server to be sure the things it is putting in the basket are the things we intended to be put there.

we can use a "path" from the user to the server that is untrusted.


In Section 3 this paper outlines a number of issues in implementing tamperproof delivery that have so far received little attention both in research and from solution providers, and suggests solutions.

the usefulness of certi.cate expiration is put into perspective.


Stage 2: Key discovery between mobile node and stationary node To establish a direct pairwise key between stationary node u and mobile node v, a sensor node u needs to find a stationary access node a in its neighborhood, such that node a can establish pairwise keys with both mobile node v and stationary node u.

a stationary access node needs to establish pairwise keys with both a mobile node and a stationary node.


·2-k = B ' We reveal the value of B ' to the .rst player (the second player already knows this value).

we condition the game G(Y ,X |V1,B,W,E)TV1 on the value of B ' , and consider the  game G(Y,X|V1,B,W,E)TV1 |B1 = G(Y,X |V1,B,W,E,B1)TV1 , with parameters (k, d-1, P(Y |V1,B,W,E,B1)TV1 , P(X|V1,B,W,E,B1)TV1 ).


The N-gram Characterization of Program Behavior It is important to note that the self database for a program consists of all N-grams that occur during training.

we do not slice each trace into segments of length N. Instead, we collect the contents of a window of width N as it slides along the trace--hence Forrest's detection algorithm is called the sliding window algorithm.


Indeed, in our initial experiments, we treat each alert as an individual hyper-alert.

aggregation of alerts is an option provided by our model, and temporal constraints are restrictions that make the aggregated hyper-alerts meaningful.


When exploiting these bugs, the attack script always holds at least one reference to the object in order to avoid garbage collection, because the bottom line of any garbagecollector is that it cannot free such a object if the garbage-collection algorithm is based on refcounting, the refcount of the object is at least 1, and thus it is not collectable; if the algorithm is based on object reachability, the object is reachable from a persistent data structure, and thus not collectable.

the bugs above the memory level are a problem orthogonal to the choice of the underlying garbage collection algorithms.


The attacker cannot cause clients to install malicious software unless the timestamp and release roles are also compromised.

due to the shared responsibility between these roles for providing update content, all three roles need to be compromised.


This is because when they are typed, the overlap area of generated hyperbola bands and tested keyboard is small.

we narrow the e.ective candidate areas by ignoring the part outside of the keyboard.


Introduction Security-critical communications devices are used to protect data con.dentiality in many government, military and industrial applications.

domain separation devices aim to control the .ow of information between classi.ed and unclassi.ed networks.


The main difference from our approach is that in our approach the security enforcement is performed in a middle layer, which is above the main OS and below the applications.

our approach can provide .ner-grained security services between applications by integrating application context information for access control.


The version of policy migration presented in this paper has limitations that need to be addressed in future work.

policy migration needs to be extended to handle the case where possession-sensitive and non-possession sensitive credentials appear in multiple policies belonging to multiple parties.


We recognise that the total elimination of an age-related performance decrement for authentication will be difficult, given the well-known decline of long-term memory with age [11], but our intention is to explore ways in which we can ameliorate this problem.

in this paper we have shown that a facebased GA system using old faces was associated with a significant improvement in older adults authentication performance.


The level of degradation depends on the time elapsed since the end of the trial period and takes the form of a delay in the user s ability to access the service, not in the quality of the service once it is received.

a trial period is followed by a degradation period that gently reminds users that the trial period has ended.


The only difference is that previously we apply panning, rotation and zooming, but now only vertical and horizontal panning is allowed.

now OPi is fine-tuned in the block level.


PERFORMANCE EVALUATION In this Section, we provide an evaluation paradigm of the proposed analytics.

the Track Area Algorithm is assessed so as to demonstrate its accuracy.


A GSNS policy is a function P with the following type signature G(I, L) × G.n(J , U) × F (U, L) .

2U ×U (5) P takes three arguments: (i) a spatial structure G .


For our purposes, a voting system insider is any person or process (hereinafter entity) in whom intentional trust has been granted.

an insider is an entity whose voting system-relevant behavior may reasonably be expected to be other than the most malicious possible and in whom the specific trust is codified in assignment of a designated voting system privilege, usually an access privilege to data or a process.


In a proof-of-concept work published on the web [21], Shamir and Tromer explore inferring of CPU activities (e.g., patterns of CPU operations and memory access) via acoustic emanations.

they investigate how acoustic emanations associated with RSA decryption and signing operations produce unique signatures per RSA private key, and how they can be used to learn the keys.


For formal de.nitions of classes W[t], see [8, 9], for example.

henceforth, we often write Op(T ) instead of O(T logd T )for any constant d. we use the notation Opto suppress polylogarithmic factors.


In this work, HMMs are used as misuse signatures.

uRLs that match against the HMMs generated by our systems can be considered malicious.


Large numbers of conclusions in privacy-preserving data mining have been obtained by researchers, most of which are based on an assumption that each party is semi-honest.

a party is deemed semi-honest when that the party follows the protocol properly with the exception that it keeps a record of all its intermediate computation results and then tries to deduce further information in addition to the protocol result.


De.ne a by F (t)=0for 0 =t =a,and F (t) > 0for t>a which is well de.ned because F is continuous.

the probability of compromise is nonzero only for times larger than a and can include the case a =0.


We assume a well-managed and professionally administered virtualizationplatform that restricts access tobothphysical resources and privileged administrative interfaces.

we are not concerned with the violation of guest VM security by an administrator of the virtualization service.


The drawback of black-box server analysis is that we may not have suf.cient information to eliminate false positives and false negatives.

we may not be able to reasonably generate all of the inputs the server should be tested on, and even for those inputs that we do generate, there is no reliable way to know if the server accepts them.


Section 4) that demonstrates such authentication transaction by means of a comprehensive example.

our framework implements policy preevaluation (1a), claim generation and veri.cation (2a, 3a), claim selection (2b), and evidence generation as well as its veri.cation (2c, 3b).


For example, the question arises whether a particular workflow instance satisfies dynamic SoD policies or certain access rights leak to unauthorised users.

due to delegation and revocation, unwanted security properties may arise such as the violation of dynamic SoD.


If two functions had the same measurement, each function s USS would be one, indicating that there is one other function that could be confused with it.

the USS metric indicates how many functions have the same side-channel characteristic.


In practice, it is not di.cult to, on an incremental basis, compute hashes of the ciphertexts sent and received over the record layer in that phase.

it is not necessary to store all record layer messages to input to the hash function all at once, as common programming APIs for hash functions allow the hash value to be provided incrementally.


INTRODUCTION Modern operating systems are vulnerable to various types of attacks.

kernel-mode malware represents a signi.cant threat because of its ability to compromise the security of the kernel and, hence, the entire software stack.


Thus, the procedure to resolve a classi.cation problem using SVMs is: (1) choosing a kernel function, (2) setting the penalty parameter C and kernel parameters as well, if any, (3) resolving the quadratic programming problem, and (4) constructing the discriminant function from the support vectors.

we view the user veri.cation problem as a two-class classi.cation problem, and the learning task is to build a classi.er based on the user mouse movements.


Table 2 and Figure 6 show the detections results of di.erent ensembles constructed by di.erent combinations of the feature representations, training sets and base classi.ers.

e1-E4 are the ensemble methods constructed by a single classi.er with a single feature representation on different training sets; E5-E6 are the ensemble methods constructed by a single classi.er with diverse feature representations on di.erent training sets.


Association rule mining identi.es sets of permissions assigned to users that imply the assignment of other permissions.

users assigned permissions A are likely to be assigned permissions B with a given con.dence (the fraction of the users assigned A that are also assigned B).


using an internal data set as the reference corpus.

we use the public Enron e-mail dataset to demonstrate how sensitive topics can be protected with our algorithms.


Contrary to intuition, our analysis reveals that dynamic diversity appears to provide limited benefit except in special cases.

it offers benefit for attacks that seek to leak information.


Unique LTCs are LTCs with local testers that read at most two locations in the tested word, and only make unique tests.

given the value read from the .rst location, there is a unique value for the second location that makes the tester accept, and vice versa.


Monitoring and enforcement guidelines will be included.


the member need not be connected to a server while accessing the object.


At runtime, TrustDroid monitors all application communications, access to common shared databases, as well as .le-system and network access, and denies any data exchange or application communication between different domains.

our framework provides the following features: Mediating IPC: We extend the Android middleware and the underlying Linux kernel to deny IPC among applications belonging to di.erent domains.


Next, we reveal the value of W to both players.

we condition the game G(Y,X |V1,B)TV1 on the value of W , and consider the game G(Y,X |V1,B)TV1 |W = G(Y ,X |V1,B,W )TV1 , with parameters (k, d - 1, P(Y |V1,B,W )TV1 , P(X|V1,B,W )TV1 ) (see Subsection 6.1).


It reports the results for the variation of ßS (on the x-axis) for different values of T .

figure 5(a) shows theFAR, while Figure 5(b) shows the IPR.


It is also of importance - to allow the replacement of cheaters -to be able to perform the desired actions of one mix server (that has been found to cheat) by collaboration between suf- ficiently many honest mix servers.

the com- putation should he possible to distribute, while maintaining all desired security and privacy properties.


PROBLEM STATEMENT In this paper we consider the problem of assuring E2E security of physiological data transfer for mHealth systems.

we want to ensure the con.dentiality and integrity as the patient data gets transmitted from a sensor to the cloud.


This makes it di.cult for system-call-based detectors to establish a concise model of normality that allows for a clean separation between acceptable and malicious behavior.

the fact that a previously unseen system call sequence is observed is not a good indication that the process is malicious.


The privacy property of TIS implies that Ais unable to perceive if the two tags are swapped.

if Aobserves a sequence of outputs from tag j and is then given an output value B randomly extracted from tag j or tag k, A cannot determine with probability nonnegligibly greater than 1/2 which tag has output the value B.


This happens due to the complexity of the constraints being introduced by the encoding functions.

using full BitFuzz the 5-minute timeout for constraint solving is never reached and STP never runs out of memory, while using vanilla BitFuzz more than 90% of the generated constraints result in STP running out of memory.


MORE DISCUSSIONS Our attacks on e-banking CAPTCHAs raise the question of whether .nancial institutions should continue to use CAPTCHAs for their e-banking services or they should leave them for more secure solutions.

the following question needs to be answered: can we enhance the broken ebanking CAPTCHA schemes so that they are immune to the proposed attacks?


First, the m keys preinstalled in a sensor can also be installed in other sensors.

a key can be shared by more than one pair of sensors.


Further(not included in the diagram), an optional cookie is exchanged prior to the core execution to mitigate DoS attacks.

server only proceeds to the crypto-intensive part of the handshake, if the client is able to replay the cookie sent to the claimed IP address.


In the following analysis of key compromise, one can often consider the timestamp role and possibly the release role as not being major obstacles for attackers.

they do present obstacles to attackers, but some projects may choose to use these roles in an automated fashion and store their keys less securely.


However, although our approach is based on a normal processor, this type of memory authentication can be applied to ensure the integrity of backup storage, because the memory authentication only verifies the backup storage, where is only accessed by the RAS, and the hash value is only updated by the RAS spill operation.

rAS spill operation is trusted because it is transparent for software and independent from other running programs.


x0,x1,...,xt,xt+1,xt+2 Denote by e1,e2 the two shortest (independent and nonzero) vectors in .. As we said above, with high probability and set X = {x0,x1,...,xt},thenwehave one of these vectors is ±(g * -h * ) and the other is the shorter of g * or h * .

with high probability the original t L(X, xt+1,i) · fi = 0 and (1) Pt ft+1 - ft+2 - i=0 vectors g * ,h * belong to the set {e1,e2, ±(e1 ± e2)'}.We can using the fact that g * ,h * .


RESULTS We were able to validate all the above hypotheses.

we found that participants task completion times were greater for EKO signature formation than for new signature formation and the latter, in turn, were greater than completion times for plain PIN entry.


Another important feature of COM is process transparency.

when using a COM component, the user does not need to care whether the component is implemented as a DLL inside its process or a separate process on local system, or even a process on remote server.


One slight negative which results from these improve- ments, though, is that we reduce the amount of collusion resistance by one; that is, the protocol can only withstand coalitions of t -1 active group members.

(any coalition of t active group members is able to determine the personal key of another active user.)


Memory Protection: Ether modi.es only the shadow page tables, which are inaccessible to the analysis target.

the analysis target is unable to detect changes to shadowmemorypermissions.


Next, we iteratively add to the candidate group one more gate, which is most correlated with the existing gates in the group and has the least switching activity.

the one speci.c gate that we add in each iteration is determined approximately by the sibling gate of the existing gates in the candidate group that switches the most rarely.


However, the method with which we choose to aggregate updates into sets is different.

assume for now that a router in AS a knows in advance all of the routes it will send during time interval I =[ts,te].let TI be the set of all tuples (r : a ' ) where the route r was sent by the given router to a router in a ' within the interval I.


hIPSweep hSadmindBOF hDDOSDaemon hIPSweep hSadmindBOF hSadmindPing (a) A hyper-alert correlation graph HG (b) P G = precedent(hSadmindBOF , HG) hIPSweep hSadmindBOF hDDOSDaemon   hSadmindBOF hDDOSDaemon hSadmindPing   (c) SG = subsequent(hSadmindBOF ,HG) (d) CG = correlated(hSadmindBOF ,HG) Figure 1: Hyper-alerts correlation graphs However, on the negative side, our method may correlate alerts incorrectly when one attack seemingly prepares for another.

our method has both a higher true correlation rate and a higher false correlation rate than JIG-SAW.


7.3 Privacy Level: E The parameter E is inversely related to the privacy guarantees of differential privacy.

at lower values of E, Laplace noise of larger magnitude is added to query responses.


We choose not to modify the NFS server code itselfbut instead implement a network-level .lter for packets arriving to or leaving from the server.

we use net.lter to queue all incoming and outgoing NFS packets to a user-space application which is able to interpret packet-level tint representations [38].


Having said that, there is nothing that precludes our approach from being applied to other programming languages.

it could be applied to C, C++ and C# if similar tool support were present.


We remark that in some cases the message m will be generated by the TPM and might not be known to the host.

the TPM signs an Attestation Identity Key (AIK), an RSA public key that is has generated, which the TPM will later use to sign its internal registers.


So it makes sense that adding the frame condition would necessarily complicate our semantics by introducing secondresult in the classical semantics of D. order quanti.ers solely for the sake of de.ning speaksfor.

=p =p = = =p =p =p =p IT ID =p =p = = = = =p =p F1 F2 Figure 4: Frame conditions for Kripke semantics the accessibility relation of t1 must be a superset of the accessibility relation of t2.


Then, for any possible strategy cooperatively employed by Quentin and Wendy in the .rst i iterations, the values Ri+1,Ri+2,...,Rt look uniformly random to Quentin (and, symmetrically, Si+1,Si+2,...,St look random to Wendy).

quentin and Wendy acting together cannot speed up the process in some clever way so that Quentin would learn Rj (or even distinguish it from random) in fewer than j iterations.


(B-Bounded Distribution) A distribution ensemble {.n}n.N , supported over R, is called Bbounded (for B = B(n)) if for all e in the suport of .n, we have .e.8 <B.

a B-bounded distribution over R outputs a B-bounded polynomial.


The decomposition of A with a partial ordering hierarchy could be represented as A = B ® B' ® C where B' represents role to role assignments.


In our opinion, overhead on a per samplebaseis mainly a stealth concern for dynamic malware analsys.

overhead should not reveal the presence of the monitoring environment.


Once authorizations/prohibitions are inferred, security policy enforcement can be carried out.

access control and .ltering policies are evaluated upon an access request is submitted, whereas admin policies are evaluated when an admin request is submitted.


Speci.cally, if .¯= 0% then Mi would contain only source-destination couples such that di(s)= -di(d).

this threshold accounts for the fact that the miscreants may transfer only part of the services, neglecting some, and we wish to allow for some .exibility.


Because the original data is unknown (thus also the current watermark-related distortion is unknown) it is impossible for the attacker to determine the real minority of changes he/she performs.

because of the goal of preserving the data value, the attacker cannot a.ord performing signi.cant change to the data.


bj is the best action that the agent can take if the state of the world is sj then the expected value of perfect information is p.·b -max p.·v.i i this is an upper limit on the total value of all possible utterances with respect to the application of criterion c. Utilitarian measures of information are expressed in terms of: if you know information x when applying criterion y to determine which action to perform then you will gain utility z over not knowing x [26].

they are de.ned in the context of some decision making act they do not place an intrinsic value on information.


This structure will allow a tool to automatically identify relevant systems and attacker information as security evidence, and aggregate the related evidence in an organized way to construct a holistic work.ow-centric argument graph.

our work is a new type of security assessment method centered around work.ow, instead of an amendment to existing security assessment methods to incorporate work.ow information.


B s simulation of the multi-ciphersuite ACCE experiment for NPI P SP to A is perfect.

suppose A breaks authentication in NPI PSP.


The objective of this paper is to raise the awareness about the security issues related to the adoption of such technologies in power grids.

we address two main vulnerabilities of the synchrophasor networks: (i) the protocols used to exchange data between the PMU and the PDC are usually not encrypted, and (ii) PDCs do not automatically sanitize the data received from the PMU.


The implication of this is that practitioners are well-advised to seek compliance with some well-balanced security bestpractice rather than chasing the latest security innovations, which generally strengthen a single link of the security chain.

compliance makes sense from a practical point of view.


Unfortunately, this idea turns out to be naïve since a party C that claims the transaction reveals the witness which when made public allows malicious miners to decrypt ., recover the signing key and then claim the bounty to an address addr ' of its choice.

this leads to a network race between the legitimate collector C and malicious nodes on the Bitcoin network.


The incident response and investigation process for Incident 216 brought to fore new requirements and challenges for dealing with large-scale multisite attacks in a collaborative manner.

there is a need to develop a framework for e.ective collaboration on incident response and investigation tasks by sharing information and resources.


A system having non-identical distributions means that each node has a di.erent distribution of time-to-compromise.

we call natural diversity the case in which all nodes have independent and non-identical distributed timeto-compromise probability density functions.


Intuitively, the security de.nition requires that the server learns nothing about the access pattern.

no information should be leaked about: 1) which data is being accessed; 2) how old it is (when it was last accessed); 3) whether the same data is being accessed (linkability); 4) access pattern (sequential, random, etc); or 5) whether the access is a read or a write.


I suggest that privacy activism is at the end of the second stage outlined above.

there is a small, mobilized, resourceful community approaching privacy, and privacy enhancing technology, as relatively isolated concerns.


That is, to recover s, A* i i and Ci are exchangeable regardless of the values taken on the remaining |A*|-1 positions.

the value at the positions in Ci can be mapped to the value at A* in terms of recovery (albeit the recovery of i the value at position A* may also be in.uenced by the i values at some other positions in A*).


Using the session-.xation technique, attackers can also donate their current sessions to victims.

the attackers intentionally let victims hijack their sessions.


The proposed data structure is a tree, called Policy Matching Tree (PMT) that traces each access control policy applied on an XML source.

the tree is built by preevaluating each access control policy and by inserting a non-leaf node for each test imposed by the object specification of the evaluated access control policy.


For space limitation, we report here only part of the results we obtained.

we only report here (Figure 1) the values of the acceleration on x-axis (of the accelerometer sensor) obtained with two users (User1and User 2), each one performing the movement.ve times(Pattern1,Pattern2, Pattern3,Pattern4,andPatterns5).


Node  also corresponds to the event of S1 being available while S2 and S3 are not available (occurrence probability: A(S1) * (1 - A(S2)) * (1 - A(S3)) = 0.014).0 Each directed edge from an event e1 to an event e2 in the graph expresses that if a bundle is compromised/available in case of occurrence of the event e1 it would also be compromised/available if event e2 occurs.

these semantics of the edges imply that, if an event is relevant, all events that can be reached from this event in the graph have to be relevant, too.


A conventional setup for EM display stealing is composed of a receiver to capture EM emanations, a device to measure the received EM trace, and a display.

the measurement device requires a wide resolution bandwidth (RBW) and a significant sampling rate [6][11][12].


IDENTIFYING A FEATURE SET We now establish a core feature set that we consider immutable.

when we analyze the key exchange protocols, we will analyze them with a view towards how they support (or do not) this core feature set in a transparent manner (i.e., the feature behavior should not be modi.ed to conform to the machination of the speci.c media keying protocol.)


Although smart cards have been gaining popularity, there is only a small literature on the implementation of cryptographic algorithms for smart card microcontrollers.

there are very few articles that discuss the trade--offs and techniques for generating RSA key pairs inside smart cards.


In practice, a small window is located in the grid, averaging the feature counts within it to obtain a local probability mass function over the features, and then generating from it an appropriate number of features in the bag {cz}.

unlike a straightforward embedding (e.g.


Therefore, it is straightforward to pose as a normal USB mouse or keyboard device and send prede.ned command stealthily to simulate malicious interactive user activities.

to verify this functionality, in our controlled experiments, we send keycode sequences to perform non-fatal operations and show how such a manipulated device can cause damages we simulated a Dell USB keyboard (vendorID=413C, productID=2105) sending CTRL+ESC key combination and U and Enter key sequence to reboot the machine.


In the absence of disinformation the value operator is monotonic, that is, we assume that adding additional information never decreases value.

if an object x is completely contained in object y,then Gxx(t) = Gxy(t), for all t. Finally, the third constraint simply states that the value of tactical information decays with time.


To achieve this goal, the cost of handling a huge number of alerts in critical situations is prorated through continuous monitoring mechanism.

this mechanism controls the size of database not to grow unruly.


This notion of security was needed to formalize the fact that deterministic cryptosystems are not secure against chosen ciphertext attacks.

if a deterministic encryption scheme is used, then it is possible that an eavesdropper observing several messages may be able to detect ciphertexts coming from identical messages.


Both applications are implemented using a higher-tier web application server that controls the lowertier BAS server.

we construct a middle-tier control system gateway that enforces attenuation of privilege to limit actions that the application server performs for speci.c principals.


The experiments presented in [9] seem to indicate that the underlying audio channel is resistant to eavesdropping.

it was shown that transmission of the key was easy to feel with the hand in close contact with the human chest enclosing a cardiac implant (using meat to simulate human chest for a cardiac implant), but was dif.cult to comprehend from a farther distance.


As we discussed previously, our tool, FAME, overcomes the limitations of those tools by conducting a complete anomaly detection and providing more accurate anomaly diagnosis information.

the key distinction of FAME is its capability to perform an effective con.ict resolution, which has been ruled out in other .rwall policy analysis tools.


However, any condition in an attack graph may mean certain amount of risk and thus should be guarded against potential attacks.

for example, having the user privilege sh(1) in Figure 2 may already allow an attacker to cause considerable damage to host 1 even though this risk is not as signi.cantasthatof root(2).the security of a network should be measured against all relevant resources with different weights.


3.2 Delay Model The delay of a single logic gate can be expressed as d = gh + p (3) where g and h are logical e.ort and electrical e.ort, respectively; and p is parasitic delay [38].

we use the delay model in [29] that connects the gate delay to its sizing and operating voltages: · L2 ktp · kfit Vdd Delay = · (1+s)Vdd-Vth 2 · n · µ · .2 t 2·n·.t (ln(e + 1))2 (4) .i · Wi + Wi+1 · Wi where subscripts i and i+1 represent the the driver and load gates, respectively; .


A somewhat more likely limitation is systematic bias.

we note that large numbers of vulnerabilities in the complete database have unknown exploitation status or dates, which limits our ability to train on these records.


The enhancement layer can only be decoded when the base layer is available.

the enhancement layer is useless for the client if the base layer is lost.


In conclusion, we proposed a simple, secure, and very ef.cient amendment of the protocol for key transmission.

our proposed amendment reduces the trust assumptions on the SIP servers, and prevents instances of the responder sharing the session key due to forking.


A primary problem NASA will fac with Federation is our NAMS requirement for a workflow approval process for authorization policy based upon an individual.

any external user requires a static one-to-one mapping th at user must be expressly granted acceC2G:  We have no firm requirements yet.


We impose cryptographic constraints on the IDs of a trigger in such a manner that we can provably prevent topologies that are non-trees at the same time not compromising the functionality of i3.

we divide a 256-bit ID into three .elds: a 64-bit pre.x, a 128-bit key, and a 64-bit suf.x.


One security issue, however, is that of a fake increment.

the host can pretend that it received an increment command from the client, even when it did not.


Note that our approach to retro.t legacy servers follows the aspect-oriented paradigm.

each .ngerprint denotes a region of code before which a reference monitor hook must be placed, and thus helps identify join points [5, 19].


However, access conditions certainly cannot represent arbitrary path conditions.

our approach signi.cantly extends the possibilities for policy speci.cation.


They consider an adversary who has "one-time access" to a decryption oracle in the second round.

the adversary may submit a vector of queries to the decryption oracle in the second round, but all queries must be submitted at once (in parallel) and cannot depend on the answers given to previous queries.


Then, S is the topology which maximizes N(G).

n(S)= Equivalent Bandwidth (bps) Figure 6: Minimum source bandwidth for the Flash Worm N(n)=1+(n- 1)(1 - p).


Among cryptographers, it is a wellunderstood design principle to maximize the entropy of the distribution from which secret credentials are drawn, by not processing these little by little.

if a server were to verify an entered password character by character as these are entered, and halt if an incorrect character is seen, then this will very clearly allow for an interactive divide-andconquer approach to determining the password of a victim.


The instant implementation revokes all related delegations with the authorization of a cascading revocation.

if Linda is revoked from PL1, Alice and Dongwa will be revoked from PE1 immediately.


An adversarial AS x is given access to a RAT oracle.

x can query the RAT oracle on routes r of its choice in a dynamic fashion and receive RAT (r)for each of its queries.


which prevents the public portion from leaking information about the sensitive key material.

any key can be used for the external authorization, but each indi vidual key will leave a matching trace in the policyDigest.


As an example that we will use throughout the paper, we consider three policies P1, P2 and P3,inthe context ofdata and resource management for a grid computing system in a university domain.

p1 is a data owner pol PolicyId=P1      <Sub ject Designation belong to{Professor, PostDoc, Student, TechnicalSta.}


We use a (63, 36, 11)-BCH error correcting code [3] to correct errors.

for every 36 bits, we add 27 redundant bits and we are able to correct 5 error bits.


These policies ensure that even when emergency situations cause some users to be absent, there still exist independent teams of users that have the necessary permissions for carrying out critical tasks.

these policies mandate that there is a certain level of redundancy in assigning permissions to users so that the system can tolerate some users being absent.


at any point of time there are only two possible values for Sj : if j is even, then Sj .


A volume anomaly at time t typically results in a large change to ya(t), which can be detected by thresholding the squared prediction error Iya(t)I2 against Qß,the Q-statistic at the 1 - ß con.dence level [13].

the PCA-based detector classi.es a link measurement vector as ( anomalous, Iya(t)I2 >Qß c (y (t)) = .


Similarly, security of the P3MTprotocol(inSec.4.2), against semi-honest Client and Server, stems from security of the underlying protocol APSI.

if APSI performs secure computation of the FAPSI functionality in the presence of semihonest participants, then P3MT is also secure.


the threat model: -Sensors: All the sensors in our mHealth system are assumed to be trustworthy.

it is not possible for attackers to compromise an existing sensor within the system without the patient noticing.


To derive time series features, we .rst construct a time series of request counts, denoted by T [·], in a 3-hour precision.

t [i] is the number of logins in the i-th time unit.


These de.nitions establish that everyone must agree that a formula (of type form) is proved based on the assumptions in some context (of type ctx).

an object of type prove(c,f) is a proof that the assumptions c imply that the formula f is true.


C2 in symbols, if each interval in C2 is exactly covered by a .nite number of intervals in C1.

for each interval I in C2, there exist a set of intervals in C1 whose union covers I.


Such behavior makes attacks using the update_location meta-command dif.cult.

because only one in .ve requests from an infected phone actually reaches the HLR, an adversary would need to create a signi.cantly larger network of infected phones than for the other write-based meta-commands.


Of the various available credential technologies, anonymous credential systems [6,3, 4]provide the most extensive set ofprivacy preserving features.

they allow users to prove properties about the credentials they own in an unlinkable manner.


This is analogous to the security of traditional digital signatures.

this means that it is infeasible to produce forgeries of the following types: T1 .nding a template T * yielding the same template signature sT * = sTi for one queried template Ti.


For this reason, attractive mitigation solutions must not only protect voice services from targeted SMS attacks, but also allow SMS service to continue.

differentiated service for text message delivery based upon the source of the SMS traf.c is desirable.


Using a month-long NetFlow data collected at our campus border router, our investigation reveals that i) many bad scanners successfully compromised inside end hosts, such tary set, A = I - G, is referred to the active space.

for any a E A, there is tra.c originating from a at some time during [t0 - T, t0 + T + T]; thus a is likely assigned to an active host during the time period.


Each of these processes is a generalization of the previous one, with increasing uncertainty, and the general equation for de.ning an optimal policy for an AC-POMDP is given by Equation (6).

if the policy/system designer is able to provide all the di.erent parameters of this equation (i.e.


In this setting, the most natural MCIS security property concerns the authenticity of information presented to the pilot.

in this setting, an MCIS is secure if an attacker cannot cause it to present false information to the pilot.


As a result, a nurse-in-training can have access to the system only if Elizabeth is present in the system.

once the roles are assumed, Elizabeth acts as a training supervisor for a nurse-in-training.


(iii) Relationship from the subclass concept to the superclass concept.


Although the solution appears quite simple in retrospect, there were a few interesting issues regarding the handling of the threat model and the security de.nitions, for payload plaintexts that may bene.t from having little or no intrinsic redundancy.

hCR protocols have to handle the combined threat of outsider and insider attackers, which must both be repelled in the best possible way, regardless of the o.ine testability of the access keys that is being placed in remote storage.


Anything a user at a particular class can do may also be done by a user at a higher class for that instance of the hierarchy.

a user at a higher class of the hierarchy may delegate some power directly to a user at a class lower than the one immediately below his.


YAf Af T (obtained from an L2 relaxation) as well as the form of the projection and gradient steps.

all these objects preserve the property that the solution only injects cha.


Except with negligible or very low probability beyond 1/2, the adversary should be unable to distinguish between any two possible access sequences of equal length and maximum set size.

consider two possible access sequences, s1 and s2, that consist of L operations, get, put, and remove, that could be made by Alice, on a set of size up to N, where L is polynomial in N. Then an oblivious storage (OS) solution has correlation hardness if it applies an obfuscating transformation so that, after seeing the sequence of I/Os performed by such a transformation, the probability that Bob can correctly guess whether Alice has performed (the transformed version of) s1 or s2 is more than 1/2 by at most 1/Na or a negligible amount, where a = 1 is a constant1 that represents a trade-o.


This suggests an alternate way to view ROA(v, .p): it is the region for which the protocol is complete.

rOA(v, .p) is the region where a veri.er will accept location claims from a correctly functioning prover with processing delay less than .p.


Second, this is a binding approach in contrast to the two delivery methods.

the hardware architecture description is bound to the hardware architecture of the virtual machine because there is no way for a malicious entity that compromised the guest OS to change the virtual hardware architecture.


The veri.er (Ed) would then verify the PRU as in the spending protocol, with the additional step of also verifying the migration step from Bob to Dave.

in addition to verifying the signature of the incproof from Bob at time tB + n, Ed also distills Dave s counter value tD from the incproof (it is included as part of CommitD ), and then veri.es that the log on Dave s side starts from tD +1 and is complete up to the current time tD + k.  3.4 Complex Usage Conditions and General-Purpose Count-Limited Certi.cates.


In order to compute a global maximum for a variable among a set of caregivers {Ci}, the problem must .rst be rede.ned in a convenient way.

it will be necessary to have an idea of the range (rmin,rmax) and precision d for these values.


Therefore, we also evaluate the tracking accuracy in the asynchronous mode.

the user s real-world trace is periodically updated (e.g., 30 mins), and the tracking on users is also periodically launched (40 mins).


2008] we consider a number of alternatives.


The emails in our experiments are indistinguishable from the emails in the corresponding attacks (Figure 12).

if in Experiment 3 we receive (through Alice) an answer from Bob, we know that Bob has entered his credentials to a site he had no reason to trust so we can consider the probability that we receive a response from Bob to be strongly indicative of the probability Bob would have compromised his credentials had he received a real phishing attack.


The root does not need to store any information about U as all it needs is stored into the symmetric certi.cate enclosed with the request.

the certi.cate contains the necessary secret keys used to create private and authenticated channels between the root and the host U. DNS Request to Root with Symmetric Certificate: R0 .- U : PR0U,DNS Req,Nonce0; R0 -.


For a pair of queries qi and qj , the dependency of query qj on qi is denoted as the conditional probability pu(qj | qi).

it is the probability for user u to issue query qj after having issued query qi (without issuing any other queries in between).


Our protocols are designed with this application in mind.

in section 5.1 we present a scheme that leverages an understanding of topic detection algorithms in the natural language processing community to control access to text about a targeted individual.


Acknowledgements We thank Igor Muttik, Michael Spreitzenbarth, Xuxian Jiang, and Ya jin Zhou for giving us their respective malware datasets.

michael and Igor responded promptly to several email requests for clari.cations additional information.


Two parties sharing a secret seed can use the PRF to produce self-synchronized pseudorandom numbers.

the i-th pseudorandom number is = ( (--- (seed)---))= i(seed) i , i Shamir [19] has proven that such one-way hash chain is cryptographically strong.


Such classi.cations are not successful against the new anonymization technique because even the cover locations lie close to the actual user locations and are realistic.

cover Locations indirectly take into consideration the user query patterns (as recommended in the work of [30]), since it generates locations close to the real locations, at times the user visited those locations.


In this paper we argue that the pervasive occurrence of routing bottlenecks is a fundamental property of the Internet design.

power-law distributions that characterize the frequency of link occurrence in routes are a consequence of employing route-cost minimization, which is a very desirable feature of Internet routing; viz., Section 2.


However, as the antenna is optimized for working with Nexus 7, nShield cannot harvest the maximum amount of power from PN532 breakboard.

the maximum power is harvested at 12 V output and the battery voltage on nShield is only 4.8 V. This voltage mismatch limits the maximum harvested power to be only 57 mW.


For example, we discover that all the .rmwares released by Cyanogenmod [22] have several vulnerable applications.

com.android.providers.media, com.android.providers.drm and com.android.providers.


The times to download the 100MB .le while under attack were reduced to 5 times and 4.5 times the baseline for LAN and WAN attackers, respectively.

having queuing on the bottleneck link signi.cantly increased the damage from the attack.


Apart from that, the computational power of the attacker is unlimited.

she can memorize disclosed memory, disassemble it, search it for gadgets, and .nd meaningful chainings of those gadgets.


In this case, we take the logical OR of all the code units taint information to determine the taint status of the new character.

if part of a two-code point character is tainted, the combination is itself considered tainted.


Apart from the transformations themselves, the instruction selection methods be known.

one must know how to disassemble the suspect programs so as to construct the actual instruction form distribution.


ACKNOWLEDGMENT We would like to thank the BlueZ group from the IBM Research Zurich Lab for their continuous support and extremely helpful insight.

we valued the discussions with Michael Baentsch (eID scenarios), Thomas Eirich(fast addition),ThorstenKramp(fast computations onJCOP),MichaelKuyper(JCOP environment),Michael Osborne(eID scenarios, card support andpersonalization), Tamas Visegrady (fast computations and crypto acceleration onJCOP), andThomasWeigold(JCOP environment, fast addition).


The SR restriction can be satis.ed in situations where there are no alternative preconditions that allow a particular value to be assigned/added/deleted to/from an attribute.

there is exactly one and only way an attribute can obtain a particular value.


BCPR di.ers from CPR in that it supports multiple CAs and that it supports a wide variety of CA sizes (we consider here CAs which have issued from 10,000 to 10,000,000 certi.cates).

bCPR s e.ciency is measured in terms of Internet bandwidth.


A possible way is to implement RBAC permissions using access control list (ACL) approach and the capability-based permissions are implemented by extension of the ACL approach.

the i-th domain (for each i) has a server that manages RBAC permissions by ACLbased access control mechanism with two matrices specifying URAi and RP Ai.


4.2 Register-bound ATRA Mitigation As discussed, the mitigation of Memory-bound ATRA seems to be di.cult, but there is no architectural limitation.

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


Variable reordering (without canaries) and stack base randomization can be e.ective against simplistic attacks.

function pointers located on the stack are protected against stack-based bu.er over.ows.


The extremes for strong connectivity are the same as for weak connectivity in Figure 4.

the worst case is a single strongly connected component, and the best case is strongly connected components for domains.


However, some applications and operating systems can also apply the principle of least privilege to installed updates.

in addition to decreasing the likelihood of successful attacks on clients by being resilient to key compromise, these systems can also isolate compromises by not giving updates and programs run from updates more privilege than required.


Generally, trust is placed on an entity (or agent), which behaves autonomously.

the behaviors of the trusted entity is out of control of the trustor.


It is up to the decryptor to obtain the required key from the trusted PKG.

an identity-based cryptosystem allows an encryptor to encrypt a message directed to a decryptor even prior to the decryptor retrieving the associated private key from the PKG.


We discuss the concrete e.ciency of our scheme when implemented with speci.c security parameters of 80 and 128 bits.

we consider the bandwidth costs for sending the MACs over the network, and the computational timings of the various algorithms at both the client and the server.


The above drawbacks of prior work motivate us to investigate secure aggregation schemes which provide end-to-end security.

a veri.er can verify the .nal aggregate without resorting to additional communication or third parties.


This is a rather slow-growing function of k, so for large n, the count appears to have good resilience against k-node attacks.

the law of large numbers comes to our rescue: if we have a large .eld of sensors and we use the count as our aggregate, we can easily tolerate a small number of compromised nodes.


We show that the gains of diversity over monoculture increase as the relative importance of minimizing false negatives to minimizing false positives grows.

if minimizing false positives is an enterprise s only goal, then diversity policies bring little gain.


The fundamental question that arises is: Does the class of computational tasks supported by these systems di.er from the class for which streaming solutions exist?

successful though these systems may be in practice, does using multiple machines (rather than a single streaming process) inherently limit the set of possible computations?


This link indicates that the DM entity has propagated a DO s data to the DC entity following agreement on a policy.

when a link exists between a DM and a DC, the DM is responsible for tracing the DC s usage of the DO s data whereas the DC is responsible for reporting to the DM on how the data has been used or is maintained if it is so requested.


This model treats all accesses to these devices as no-ops.

all memory-mapped and port-mapped device reads return thevalue 0xFF, and all writes are discarded.Together, these steps complete the delusional boot and achieve theendgoalof runninga guestVMonthe production server with enhanced isolation properties.


In the context of specialising an RBAC P program ., H2A we note that the de.nitions of ura, pra, senior to and ds are part of the object level information that is used to protect the ob ject level database in our approach.

moreover, the sets of clauses de.ning the extensions of the ura, pra, ds and senior to relations are static relative to the set of active atoms that are implicit in .. the set of active facts will change dynamically as users activate and deactivate roles.


When we form W1 ; W2 or W1 IW2, we include all constraints in C1 and C2.In addition, we may create new constraints, governing the execution of some steps in S1 and some steps in S2.However, we prohibit the addition of constraints in which all the steps are contained in either S1 or S2 (the assumption being that they would have been created earlier, if required).

any constraint that is added when we form W1 ; W2 (or W1 IW2) has the form (., S1,S11), where S1 .S11 .S1 and S1 .S11 .S2.


Therefore, the .rst-step approach towards assessing the risk of such re-identi.cation attack is to study the resource database.

we explore the identi.ability of the crawled LinkedIn user pro.les in our simulated resource database to assess the re-identi.cation risk.


Also suppose that policy thresholds ti are public, and [[Q]]ss = s ' such that s ' (out)= o.

the actual output of the ss query Q is o, and each Pi learns either the output o of the query, or  which principals Pj rejected the query.


U 2R : U .. 2R and R2P : R .. 2P are relations that are functional in their .rst coordinate, modeling user-to-role and role-to-permission assignments.

u2R(u, M) and R2P (r, N) are true i. user u is allowed to play the set of roles M and role r can execute the set of permissions N respectively.


After the region of data memory is determined, sYSMALLOc() sets that as the top chunk and then splits off a chunk of size nb to satisfy the request.

line 39 writes (E - S - nb)|PREV_INUSE to location S+nb+4, see Figure 4.


CONCLUSION AND FUTURE WORK In this paper, we extended and improved the previous work on property-based bootstrap architectures [12]withrespect to di.erent aspects.

we strongly improve the solution for software version rollback problem.


The Role Mining is based on the following kinds of user-related data: - For each target system, the information if a user has got an account on the system or not.

we take the list of systems the user is connected with.


At .rst glance, delegation by warrant proxy signature can also implement the functionality of 1-out-of-2 signature.

the original signer can specify that only one of the two signatures can be signed by the proxy.


We collect compliance degree history c1,c2,...,cn of adevice by means of Monte Carlo simulation.

given a device s state machine we start from state 0 and then follow thestochasticprocessof thisdeviceas itgoes fromonestate toanother.


Security assurance cases [3, 6, 11] were proposed to demonstrate the security attributes of a given system by putting together a structured collection of security-related claims, arguments, and evidence.

the graphical Goal Structuring Notation (GSN) is often adopted to present security assurance cases [11].


(Our experience with a real program that analyzes web logs is described in Section 6.)

the log entries are compared against signatures of known attacks.


Finally, we use Zip.an Distribution to choose queries in our query load.

if a particular query has a rank jin the ordering, we choose this query in our query set with prob 1 j Lt 1 ability Pj = , where N = is the Normalization N i=1 i n(n+1) Factor and t = 2 is the total number of all possible queries.


Compatibility with Existing Software Systems: Unlike isolation techniques that monopolize the highest privileged execution level of the target platform (e.g., Trustvisor), SICE does not exclude running legacy workloads (e.g., a hypervisor with multiple VMs) on the same physical platform.

a platform using SICE can o.er isolated environments, and at the same time accommodate legacy virtualization software.


TRS schemes must satisfy: Veri.cation Correctness.

all signatures signed according to speci.cation are accepted during veri.cation.


If the responder were to create a new state and send a new Message (4), and a new sa ' for a replayed Message (3), then an attacker who compromised the initiator could replay a recent session with the responder.

by replaying Message (3) from a recent exchange between the initiator and the responder, the attacker could establish a session with the responder where the session-key would be identical to the key of the previous session (which took place when the initiator was not yet compromised).


In our protocol, we use the homomorphic properties of the Paillier cryptosystem to compute in a privacy-preserving fashion the availability of all users involved in the scheduling process.

one can verify that the Paillier scheme satis.es the following: D[EKP ,r1 (m1) · EKP ,r1 (m2)mod n 2]= m1 + m2 mod n D[EKP ,r(m1)m2 mod n 2]= m1 · m2 mod n where ri,r .


In this paper, a detailed treatment of the security o.ered by secure encoders based on convolutional codes is provided.

their strength is evaluated against chosen and known plaintext attacks, whose running time and plaintext requirements are determined for any success probability.


BACKGROUND 3.1 Trusted Computing Base The many platform components, technologies and concepts which are responsible for the correct functionality and security of a computing platform, constitute the Trusted Computing Base (TCB).

a platform solely relies on the TCB components for functionality and security enforcement and therefore to evaluate a platform s trustworthiness it is necessary to assess its TCB.


We evaluated the performance of CBMC-GC on a number of tests that are typically applied to assess the e.ciency of STC; furthermore, we show the applicability of CBMC-GC to the problem of secure two-party computations with private functions (i.e., the case where the functionality to be computed is only available to one party).

we consider the size of the circuits produced by CBMC-GC and evaluate their runtime when used in combination with the above mentioned highly e.cient STC implementation [20].


The most severe case occurs at k = 80 for Sen1 in 200D2 with BA = 1.

some target was uniquely identi.ed since all other matching records in R2 were correctly identi.ed as having timestamp T1.


The key idea in our construction is to .rst design a scheme having imperfect completeness.

for every possible decryption key, there exist a negligible fraction of (valid) ciphertexts which cannot be decrypted by this key.


Inputs over these interfaces are treated as input from party 0 when evaluating the program C ' .

the privacy of these inputs is guaranteed even against IT adversaries.


Note that each a~ is the sum of a subset of the coefficients {a~ 6 }.

for all k E {0,... 2t} and all i,j E {0,...,t}, we have a~ = E~,j:i+j=k ai,j.


Our goal in this paper is to understand why there is so much diversity of requirements.

what causes some sites to require very restrictive policies when others clearly manage with less?


Then the attribute declaration for her DoB looks like DoB = 03/07/1986 :: BMV.driverLicense(DoB), Gov.passport(BirthDate) :: sensitive Because the disclosure of attribute values in a credential can be separated from the disclosure of the credential, one purpose of the attribute declarations is to uniformly manage the disclosure of an attribute value that appears in different credentials.

the policy author gives disclosure policies for attribute DoB, instead of assigning separate disclosure policies for BMV.driverLicense(DoB) and Gov.passport(BirthDate).


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

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


We now turn to the main question raised in this paper: Which is the best overall con.guration to use for regular expression matching?

we use matching speed per implementation area as the key metric for this optimization.


Our approach is to treat a policy as a four-valued predicate.

a policy maps every requested access to either grant, deny, unspeci.ed, or con.ict.


or more advanced geolocation techniques seems promising.

one might leverage collocated landmarks to build a model of service overhead to more accurately simulate landmark-target interactions during model building; our preliminary results using CBDG using TCP-based models are favorable.


This is a general application of the traditional 2-man rule (i.e., separation of duty) that can be applied to two different tasks, Prepare and Approve, with two different required roles.

if the employee, who initiates the reimbursement process, happens to be a manager, then the manager should not approve the expense reimbursement request that he initiated even though he has both Employee and Manager roles.


The implicit .ow that arises from these language constructs must not be ignored, but that requires control dependence instead of analyzing code block structure only.


Note that the analysis errs on the side of .nding spurious dependences and impacts.

these analyses are simple maydepend/may-impact analyses, which are both .ow and context insensitive.


The semantics of these labels are maintained as invariants by the model.


Put more succinctly, the ends of every edge that has an in.uence on authorization decisions must connect both the owner and the accessor.

such an edge must contribute to the connectedness between the owner and the accessor.


The e.ciency gains that can be realized by materialized views do not come without cost, however.

materialized views (i) require much more space within the database (1000s of rows) when compared to dynamic views (stored as a single query), and (ii) must be regenerated onthe-.y to remain consistent with changes made to the tables and views over which they are de.ned (e.g., when logical policies are edited).


We will refer to such type of slots as Silent Memory Slots (SMSs).

a node a uses these slots as follows: The SMSs are populated as for the regular tracking slot, considering the IDs of the .rst nodes that a meets.


The key idea to improve performance is to execute the comparison operations in an order such that the most expensive operations are executed last.

during the similarity index computation(either s t, for the text section, or s i, for the images), we keep the n (withn = 10 for thetextpart and n =5fortheimagepart) similarity values forthe mostsimilarpairsof tuplesfound sofar.


In [16], authors present a new formation control framework for small scale, distributed mobile robot teams that can adjust their formation to adapt to a variety of circumstances.

a neighbor-referenced decentralized approach is proposed to generate and keep geometric shapes.


Firstly, C-FE avoids various impossibility results that affect FE.

simulation-based security de.nitions are typically impossible to achieve for functional encryption (e.g., [53, 19, 8]), unless severe limitations are placed on the number of keys that can be issued (e.g., [32, 30]).


x0.X0  Figure 3: Discrete-time dynamical system b) Figure 4: a) Nominal system with signal decomposition, and b) the same system under a stealth attack 3.1 Signal partitioning and attacked system To formalize the notion of stealth attack, we .rst divide the measurement and the control vector into their nonsecure and secure parts.


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

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


The 1 Still, it should be kept in mind that having access to a random oracle such as GsRO is not something that can be emulated in the standard model using an e.ciently computable hash function family.

the impossibility results of [6]still hold even with respect to this model.


However, by combining the HS and BF methods into HS+BF seems to improve the HS method in all four scenarios.

by adding an extra bit to the hash value per element for the Bloom .lter representation has the potential to signi.cantly improve the detection rate.


In that architecture, the LPA forms the locus of a domain s policy management functions, as displayed in Figure 3.

dynamic policy changes in Domain 1 are handled by the local LPA in Domain 1, which transparently hooks into the local domain and provides functions to 1) analyze local cross-domain policies and make analysis results accessible to other domains but only through appropriate CDSs, and 2) deploy policy changes into edge gateways and security guards.


On the one hand, retaining DFA-like transitions allows us to adapt and use common DFA operations with only slight modi.cation in most cases.

xFAs can be constructed individually and later combined using standard techniques.


after m appears there is no alternation in the trustworthiness of user.


Assigning a weight to connections between activities is a .exible way to model the business process break-down structure.

weights indicate if there is a strong or a weak decomposition.


While concept analysis is asymptotically ine.cient its complexity is exponential in maxi(|CodePats(ext2 apii)|) our experiments showed that it is e.cient in practice.

our analysis completed in about 2 seconds for ext2, and in just over 310 seconds even for the largest of our case studies.


Especially, if we examine traditional anti-malware tools, they are typically deployed within vulnerable systems and could be the .rst targets once malware infect a computer system.

though these traditional in-host tools are valuable in monitoring system behavior or detecting malicious activities (with their native access inside the systems), they are fundamentally limited in their isolation capability to prevent themselves from being infected in the .rst place.


Formally,givenasetof usersalongwiththeirprivilegesandasecurity property H, do there exist fewer than k users whose privileges put together enable those users to violate H?

can we determine whether harmful sequences of actions can be carried outby anygroupof k users out of a total of n users.


Therefore, our attestation scheme measures not only the binary code of P and its initial input, but also, in a recursive fashion, checks both the correctness and the timing of runtime inputs from relevant sources.

for every data relevant to P s execution, our scheme measures the data itself, its generator and the inputs which result in the data.


First, we show that a number of typical malware behaviors appear plainly in a whole-system provenance record.

when malware spreads from one provenanced host to another, we can observe the communication between the infected process on one host and the target process on the other using socket provenance.


One of the main advantages of this approach is that it enables immediate revocation of security capabilities.

the SEM checks whether the public key used has been revoked and if so, prevents immediately any entity from using the corresponding private key for decryption and/or digital signature generation by not completing the threshold cryptographic operations required.


Once the client has received the challenge it generates a new nonce, NC , sets M = Z||NS||NC ||IDS ||IDC and .nds a partial hash preimage of a Q-bit target string whose integer value is in the range [0,D].

the client has to .nd X such that H(M, X) mod 2Q : D. Now the client replies with its nonce, NC , and the puzzle solution X, and the other values it received.


Figure 5: Malware analysis framework evaluation There is a constant tension between these factors, which is represented as a triangular surface in Figure 5.

while trying to achieve better results for one factor, the anal  ysis technique has to make compromises in remain two other #  #  #         !


We implement the TLR library for Mono and modify the Linux kernel in two ways: (i) implement the TLR system call, and (ii) change the kernel to eliminate all dependencies on resources only available in the secure world.

we (i) modify the interrupt masks appropriately, (ii) disable certain cache control initialization code, and (iii) remove some    0 1 2 3 4 5 6 7 8 9 Time (s) Figure 11.


In our approach, the log is implemented through tables stored in databases at the various organizations in the federation.

we illustrate how, by using di.erent types of queries and triggers on such tables, security properties of the federation can be veri.ed.


Note that G(U|VP )= G(U|VQ) and that G(U|VQ)= 1 <G(U|VP ).

only the average case measure can distinguish between the partitions P and Q.


Our scheme utilizes the concepts of ABE for access control.

for this work, we used Hierarchal CP-ABE scheme in which the access policy lists the hierarchal dependencies of attributes in the permissible attributes set ...


If the processor is executing outside the boundaries of the module, it has only limited rights to access the module s memory.

destruction of the module is also only possible from within the module: this is why we use the term self-protecting module (SPM) for protected modules in Fides.


An entity E0 aims to collect a series of electronic items from entities E1 and E2, delivering the appropriate tokens in return.

no item in isolation is of any value to entity E0.E0 is interested in collecting all or none of these items.


We note however that such a system also requires the decryption algorithm in the smart card to be properly implemented [1].

the implementation should not leak information about the decryption key.


Further delays would be incurred because outbound inter-AS level redirection requires human intervention in the current Internet.

inter-AS tra.c redirection can only be manually con.gured since inter-AS links are selected by the coupling of BGP and IGP (e.g., OSPF) protocols [52].


ACKNOWLEDGMENTS The author is very grateful to Leonid Levin and Drue Coles for useful discussions.

discussions with Drue were instrumental in crystallizing the key concepts, while Leonid pointed out the lower bound for the subset separation strongly tamper-evidence schemes.


Conveniently, we can merely reuse our existing Feistel S-Pad construction as an X-Pad, for which we have a signcryption of the form fR(fS -1 (w)).s, where s is short.

de.ne a Feistel X-Pad to be a Feistel S-Pad with length parameters chosen appropriately for X-Pads.


Buckets are greedily .lled with blocks in the stash in the order of leaf to root, ensuring that blocks get pushed as deep  ' down into the tree as possible.

a block acan be placed ' in the bucket at level e only if the path P(position[a]) ' to the leaf of block aintersects the path accessed P(x) at level e. if P(x, e) = P(position[a'], e).


For example, instead of seeing semantic-level objects such as processes, .les, and kernel modules, we only see memory pages, registers, and disk blocks from outside the VM, making it dif.cult for out of the box malware detection.

the out of the box approach gains tamper resistance at the cost of losing the native, semantic view of the host enjoyed by the in the box approach.


A Flash Worm uses a priori information in the form of a hit list.

the Target Set is explicitly enumerated and carried with the worm.


This rate, t , is thus the probability with which two peers, upon 15 s 30 s I-Worm/Bagle.Q 76% 81% I-Worm/Bagle.S 76% 73% I-Worm/Mydoom.D 97% 93% I-Worm/Mydoom.F 97% 93% I-Worm/Jobaka.A 97% 93% I-Worm/Sasser.B 97% 93% I-Worm/Sasser.D 97% 93% Worm/Lovesan.A 97% 93% Worm/Lovesan.H 97% 93% Table 1: Probability, t , with which two peers, upon exchanging snapshots of their internal behavior, can decide using intersection of snapshots that they are, more likely than not, both executing the same worm during some window of time, for windows of 15 and 30 seconds, per our prior work [21].

percentages of all possible pairs of samples |S1nS2| from some worm for which = 0.5, where S1 max(|S1|,|S2|) and S2 are snapshots, unordered sets of system calls executed during some window of time.


e means that there is a strong mutual trust between u and v. a user only deals with the others she directly trusts (i.e., there is no issue of transitive trust ).


In contrast to our evaluation on x86, we conducted micro benchmarks for ARM.

we used an Android Nexus S device running Android version 4.0.3.


The system is .exible enough to support newer, cloud-oriented authentication techniques.

we have integrated the system with implicit authentication, and we have described several simple end-to-end use cases with our authentication framework and implicit authentication.


As we demonstrated in Section 3.2.2, writing idioms only requires an understanding of how the kernel performs the conceptual operation.

kernel analysis is independent of hook analysis, and writing idioms does not require understanding any policy-speci.c code written in kernel modules such as LSM-SELinux.


An insigni.cant attribute-value pair is removed from the cau r if it does not negatively impact the signi.cance factors for the attribute sets in which it was included.

once the attribute ai is removed, recalculate fc.If fc falls below the threshold value, return ai to the attribute value set.


By allowing the adversary to have oracle access to OpenR, we make it very powerful.

for existing receiverdeniable constructions, calling OpenR once will give the adversary access to the private decryption key sk.


Mobile differs from .A and .hist by tracking history on a perobject basis.

both .A and .hist represent a program s history as a .nite or in.nite sequence of global program events, where the set of all possible global program events is always .nite.


Comment: The decision whether or not to serve an RTT must be a deterministic function of the entered username/password pair.

for any speci.c pair of username and password values, the user is either always asked to pass an RTT, or is never asked to answer one.


Again, this approach is not unique, but it o.ers an opportunity to study its strengths and weaknesses in the context of our network security domain.

we were curious to see which general techniques (if any) we could begin with, and how signi.cantly these techniques needed to be modi.ed before they would be used by our analysts.


The problem is that the formula speci.es an only if condition, and not an if and only if.

the expression evaluates to true even if the expression to the right of the inference is false.


sc1 n Sc2 (11) z(t) could be an instance of Ye c1(t) or an instance of Ye c2(t).


define a generic software measurement structure in [7].

the measurement structure does not contain security specific concepts.


Current authorization solutions for collaborative systems focus on centralized policy management with privilege credentials.In many Grid systems for example, administrators of the VO issue credentials to users that determine the resources and permissions a user can hold.

the permissions of a user are pre-assigned and the authorization only checks the validity of the credentials.


Because the proposed framework requires additional information to be transmitted by the Owner to both Publishers and users, we store all such information into a directory server (which can also be shared among different Owners belonging to the same domain or to federated ones), to limit the overhead that these operations require.

as depicted in Figure 1, the directory server contains three kinds of entries: the Publishers entry, which is shared by all Publishers and contains all encrypted documents that they are entitled to manage, plus additional information they need for the correct functioning of the system; the Users entry, shared by all the subscribed users, storing common information; and a distinct User ID entry for each single user, containing needed information to verify the security properties.


Our encrypted and authenticated checksums s 1(B) and s 2(B) allow the client to verify the authenticity and freshness for the block B.

the freshness property is due to the fact the authenticated encryption uses a time and position dependent key.


Despite the similar purpose of detecting and recovering from unknown memory corruption attacks, our approach also di.ers from these techniques.

our approach automatically identi.es the vulnerability (at the binary level) exploited by novel attacks, and prevent future attacks by signature-based detection and .ltering.


Instead, it provides a generic platform that other modules can leverage to perform their malicious actions.

mebroot provides functionality to manage (install, uninstall, and activate) such additional modules.


R, where C denotes a set of input challenges (usuallyencoded as a bit string) and R is a set of responses.

for a single device, providing the same input Ci to the PUF will yield approximately the same result Ri.


In this paper, we formulate de.nitions of UC ring signature toward various security levels.

we propose an ideal ring signature functionality (uf ,anon) FrSIG which is convertible by a level of unforgeability uf and a level of anonymity anon.


We found that the development of a formal semantics alongside an implementation helped us us disambiguate design choices and resolve ambiguities.

the formal semantics allowed us to safely combine multiple TMI actions and different security managers into a single, atomic authorization decision.


But since a di.erent salt is used to encrypt each .le, an adversary may not need to use all possible salt values when populating an HMAC-SHA1 key dictionary.

mallory would only need to populate the dictionary using enough di.erent salt values to ensure, with high probability, that one of the salt values that a user uses when encrypting her .les will collide with one of the salt values that Mallory used when creating his dictionary.


Furthermore, control theory provides a common language in which to describe both the physical dynamics of the system, as well as the impact of the attack and defense.

we provide a passivity-based approach for modeling and mitigating jamming and wormhole attacks.


Utilizing the HTML5 keygen tag, the hybrid generation mode is not supported by IE@D, Ch@iP5, and S@iP5.

neither Internet Explorer, Safari nor the iPhone 5 at all are compatible to the hybrid generation mode.


4.4 Limitations Our current prototype does not enforce its policies on operations relating to capabilities, .le mount points, signals, message queue, and semaphores.

low integrity processes performing these operations are not restricted.


In particular we choose a 4-gram model for HTTP as well as JS-Stat and use 3-grams for JS-Dyn.

we consider the regular two-class SVM that learns a separating hyperplane with maximum margin and the corresponding one-class SVM [40].


This translational research, commonly referred to as bench-to-bedside, requires a very di.erent approach compared to traditional methods [16].

translational research often requires integrating data from multiple systems and of di.erent types.


Many machine learning algorithms can be written in dual form by expressing sought feature vectors as linear combination of f(wx1),...,f(wxn).

if w = a1f(wx1)+ ···anf(wxn)for some aw.Zn,then nn X X fw (wxi)= aj ·(f(wxi),f(wxj))= .


(y ), but the database cannot be feasibly accessed in any other way.


However, we can estimate the boundary of near and far EM fields from the results, where the intensity fell exponentially up to 50 cm comparable to the wavelength of the leakage frequency, and then reduced linearly from greater distances.

the near EM field was observed up to 50 cm and the far EM field was observed from greater distances.


Intuitively, the authorization decision of an OC policy can be determined by examining only the component of social network in which the owner is located, plus the additional knowledge of whether the accessor is in that component (CG(u; v)).

even if there may be vertices and edges outside of the owner s component, they never in.uence the authorization decision.


Its score can be represented as a linear expression with the symbol D(l, xt-1) and the symbol related to xt, and simpli.ed using the fact that all nucleotides between the two columns are known.

an expression that compares the scores of two different connection paths can often be reduced: for example, we know that a path with a score D(l, xt-1)+ C1 + s1(i, xt) is better than the one with D(l, xt-1)+ C2 + s1(i, xt) if the constant C1 is smaller than C2.


Note that the minentropy of a sample distribution captures an estimate of the amount of randomness that can be expected to be derived from a single sensor reading rather than the entire distribution sample.

a stationary accelerometer can support the creation of 3.4 random bits per one 30-bit accelerometer sample.


A central contribution of this paper is a set of methods for transforming raw data into features suitable for consumption by classi.ers.

we use HMMs in order to build models from the time-series data, thus producing inputs for our classi.er.


As a result, the transmitting node A will ob serve normal carrier sensing times.

in our experiment the reactive jammer produces sensing time cu mulative distributions that overlap completely with the case of no background tra.c.


Although the adoption of RBAC introduces bene.ts from both a system and business perspective, many organizations are still reluctant to deploy role-based access control systems, since there are still some important issues that need to be addressed.

to maximize the advantages offered by roles, the model must be customized to capture the needs and functions of the company.


1.1 Contribution and Comparison We study the power of transferable non-equivocation in the context of AMPC and demonstrate how to improve the resilience of AMPC from t < n/3 to t < n/2, without any synchrony assumption.

we present a general MPC protocol in a completely asynchronous communication model with n = 2t + 1.


In our case, the speci.c peephole optimization targets the removal of return opcodes.

for return opcodes introduced by non-ret instructions opcodes, we simply substitute these instructions with others that bear the same semantics but do not contain any return opcode value.


It should also be noted that as current proposals for coordinate systems assume that the nodes partaking in the system cooperate fully and honestly with each other that is that the information reported by probed nodes is correct this could also make them quite vulnerable to malicious attacks.

insider attacks executed by (potentially colluding) nodes in.ltrating the system could prove very effective.


4.1 Threat Model We consider a threat model in which the adversary can either corrupt protocol participants (and make them behave maliciously) or transmit spoofed messages on behalf of arbitrary entities.

our focus is on a scenario in which agents behave maliciously and attempt to disrupt the protocol by sending spoofed messages to honest customers.


DEFINITIONS We are interested in analyzing generic schemes for asymmetric encryption assuming ideal hash functions.

we are working in the random oracle model [13, 5].


For example, a rule may forbid performing action a for the purpose of marketing unless the treatment purpose is also involved.

it should either be that the marketing purpose is not involved, or both marketing and treatment are present.


In addition, while leftover ssh keys only allow people with the corresponding private key (normally the AMI image creator), to obtain access to the instance, passwords provide a larger attack vector: Anybody can extract the password hashes from an AMI, and try to crack them using a password-cracking tool (e.g., John the Ripper [9]).

ssh keys were probably left on the images by mistake, and without a malicious intent.


It has been argued that it would be of practical value to be able to de.ne constraints in terms of organizational structures, rather than just the identity of particular users [17].

the .rst contribution of this paper is to introduce a model the Graph k-Colorability problem can be reduced to a special case of WSP in which the work.ow speci.cation only includes separation-of-duty constraints [17].


The current implementation supports the computation of symmetric binary functions.

binary functions whose output does not depend on the identity of the those who provide inputs.


A smart energy network consists of three type of devices: coordinator (FFD), router (FFD), and end device (FFD or RFD).

a coordinator is termed as the Trust Center (TC) that is responsible for network and security management in the smart energy network.


The adver- sary wins the game if b = b'.

an OSBE scheme is oblivious if for every probabilistic interactive Tufing Machine .,4, IPr[.A wins the above game] -½[ _< f(t), where f is a negligible function in t. (The adversary cannot do substantially better than random guessing.)


However, they are not suf.cient in our framework, since each group member also has access to some secret information (i.e., Si for Ui), which is used to compute the group keys.

forward secrecy doesn t imply that the adversary cannot discover the subsequent group keys if he/she further has the secret information only known to some past group members, and backward secrecy doesn t guarantee that the adversary cannot discover the preceding group keys if he/she is further provided the secret information only known to some new group members.


The signatures produced will have the same authentication functionality as the MACs in the symmetric case.

the update client will use the public key of the update server to verify Sig1, and hence, the authenticity of BF.


IMPROVEMENTS TO ADDRESS-SPACE RANDOMIZATION ARCHITECTURE Our attack on address-space randomization relied on several characteristics of the implementation of PaX ASLR.

our attack exploited the low entropy (16 bits) of PaX ASLR on 32-bit x86 processors, and the feature that address-space layouts are randomized only at program loading and do not change during the process lifetime.


ACKNOWLEDGMENTS The authors would like to thank the management team, development team, the researchers, and the architects for their support and guidance.

we would like to thank Mike Day, Peter Hofstee, Dan Brokenshire, Jeremy Kerr, Mark Nutter, Arnd Bergmann, Mike Kistler, Sally Tekulsky, Mike Perks, and Vladimir Zbarsky.


However, if A does not rate B, it should not be able to claim otherwise later.

a must be able to rate B only if it has received content from B.


Third, while J¨urjens distinguishes between potential and explicit nondeterminism in order to de.ne a re.nement preserving property of con.dentiality and integrity, he does not rely on this distinction in the de.nition of his information .ow property.

a secure information .ow property for UML machines is formalized such that each behavior re.nement to a deterministic UML machine satis.es this property, i.e.


Furthermore, it is to be guaranteed that the initial states of the real and the ideal systems are compatible.

we must verify that the MMU is set up according to our model requirements, the kernel invariants are satis.ed, the partitions memory and the interrupt .ags are con.gured correctly.


For ex-3.3 Results Overview ample, VMMs (e.g., Xen) execute the privileged VM (Dom0) with the role of a host OS, and strictly divide the physical address space and privileges between Dom0 and the VMM.

the VMM is speci.cally designed to be protected against a malicious privileged VM.


For iOS, we concluded that no service provider in our study was using custom schemes correctly.

no service provider could correctly determine the identity of its message recipient.


However, such attestation mechanisms provide only integrity veri.cation at load-time but not at run-time: An attacker can change the .ow of execution of a program, e.g., via bu.er over.ow attacks [2] that are despite numerous countermeasures still a great security concern in software systems today.

new runtime attacks were found based on so called return-oriented programming [5, 31].


Figure 8: Empirical CDF of sources in IPv4 address space for the 9 zombie armies illustrated in Table 2. all sources (represented with the blue dashed line).

certain armies of compromised machines can have very di.erent spatial distributions, even though there is a large overlap between zombie-friendly IP subnets.


Figure 7 shows the impact of such caching on a real network.

we observed the response times for the GPRS Attach AT command, which connects a device to the data services provided by the network.


Additionally, the results provide both quantitative and anecdotal information that can be effectively used in classroom presentations regarding social engineering attacks and mitigation.

this study provides insight into the ease with which a secure Information Technology system can be compromised through what Mitnick calls old fashioned manipulation [5].


Unauthorized replacement or update of gateway executables on the RP resources  A compromise of the science gateway server is a serious risk and is out of the scope of control of the RPs, however, the first gateway security requirement mandates that the gateway owner/developers notify the TeraGrid when a gateway compromise is detected.

a gateway compromise can easily lead to the compromise of the gateway's proxy credential and its unauthorized use to access TeraGrid resources.


2.1 Graph Data Models Graphs are a very natural representation of data in many application domains, for example, precedence networks, path hierarchy, family tree and concept hierarchy.

we emphasize on applying graph theory to redaction by using two existing data models, namely a RDF data model [16] and the OPM provenance model [20].


Wefurther analyzed the difference between IP count and the actual bot count by examining their temporal characteristics.

figure5displays the number of unique IP addresses observed during the ten days that we were in control of theTorpig C&C. After the initial spike when the bots started to contact our server, there was a consistent diurnal pattern of unique IP addresses with an average of 4,690 new IPs per hour.


This is because we have deployed a part of our honeypots in that they can make a communication with Win32/Con.cker worm.

we could get high quality shellcodes which are sent from attackers only after session establishment.


This solution cryptographically links the platform and the SSL endpoint properties.

it connects the endpoint properties to the physical platform through the hardware TPM AIK.


However, for the purpose of the paper, this is not a major limitation.

all possible attacks GA are relevant for B as well (GA .


In this case, the channel matrix per h11 h12 ceived at transmitters will be F =instead of H. Using f21 f22 ZF-BF, the received symbol will become: -1 v y1 h11 h12 h11 h12 p1m1 n1 =v + y2h21 h22f21 f22p2m2n2 v (6) 1 0 p1m1 n1 =v + h21f22-h22f21 h11h22 -h12h21 p2m2n2 h11f22-f21h12 h11f22 -f21h12 The .rst insight in this equation is that no matter how rx2 forges and reports the CSI, rx1 always receives the signal y1 = v p1m1 + n1.

it is impossible for rx2 to inject any payload into y1 by forging CSI, i.e., misleading the decoded signals at rx1.


Our .rst observation is that the asymmetric (namely, noncommutative) nature of matrix multiplication gives rise to an interesting phenomenon in the GSW scheme: when multiplying two ciphertexts with noise levels e1 and e2, the noise in the output turns out to be e1 + poly(n) · e2.

the noise grows in an asymmetric manner.


7.1 Security Proof We are going to show that there exist no (real world) adversary A who can trace tags in a system of issuers and randomizers that apply our insubvertible encryption scheme.

we are going to show that no matter how the adversary A behaves, he cannot trace a tag unless he brakes one of the properties of our insubvertible encryption scheme listed above.


To locate the closest peers, Overnet uses UDP messages and iterative searches.

the querying client sends a series of UDP messages to a sequence of peers, with each peer in the sequence having an ID that is closer to the key.


An identity management system can moreover provide the capability to let the user browse through the concept lattice structure.

the user would be given the opportunity to explore her partial identities by means of concepts.


Unfortunately, modern browsers do not allow a host to differentiate its content from the content of third parties.

all content executes under the same credentials.


For the .rst challenge, we introduce an incomplete information game model [20] in which each user is assigned a type e, whose probability density function f(e) indicates the distribution of the user s privacy level.

each user is aware of only the privacy level distribution, not the actual privacy level.


For lowfrequency, synchronous communication channels (e.g., those that access XenStore), this method isolates individual transactions and resets the service to a fresh state at the end of every processed request.

every single request is processed by a fresh version of the serviceVM.2 The overhead of imposing a restart on every request would be too high for higher-throughput, concurrent channels, such as NetBack andBlkBack.FortheseserviceVMs,thehypervisorprovides aperiodic restart timer that triggers restarts at a con.gurable frequency.


(Vacuous privacy policy) We say that an ideal functionality ID is vacuous if there exists an ef.cient extractor Ext such that for any PPT algorithm A there exists a simulator S so that for any database D: |P(AID (1k)= 1) -P(S(ExtID (1k))) = 1)|= .

(k) we .rst extract all useful information from ID without any speci.c knowledge of the database, throw away ID, and use the extracted information to simulate ID against an arbitrary adversary.


Accordingly, since the accuracy of these parameters is extremely high, the computational error is also decreased to an extremely low level.

the length of integers increases not only the security but also the accuracy.


Suppose that the adversary plays i a pure strategy and attacks z .Z.

then there exists a pure sender strategy f .F with the same harm as the expected harm of s. Proof: We construct f as the expected .ow of s. L for an edge e .E, set fe = qifi .


For simplicity, we start with a function revealing, pattern revealing construction, with no tweaks, for general function evaluation.

we are given an arbitrary (ef.ciently computable) function F so that the client should be able to compute F (f, x), if the authority, after seeing .


Alice is trying to get a single bit of information to Bob in such a way that anyone else that receives the message cannot understand it.

alice is going to encrypt the message in such a way that only Bob can decrypt it.


One of the main conditions for acceptability of the social experiment is the absence (or exhaustion) of alternative testing possibilities.

there needs to be a clear indication that the experimental introduction into society provides information that cannot be obtained before performing the social experiments.


The third policy example states that S3 can only be entered from S0 but not from S1 or S2.

this policy only allows transition from state S0 to S3, but neither the path S0 .


The framework allows to cover unknown confused deputy attacks and attacks by colluding applications that communicate either directly or indirectly.

the attacks of Soundcomber [11] can be prevented that rely on indirect communication of colluding malicious apps over covert channels in Android system components.


For the rest of this subsection, we assume that we are given a data exchange setting (SoToEsto)and a source instance I. Moreover, we assume that Jis a canonical universal solution for this Aon data exchange problem.

jis such that IJis the result Aon of chasing Iwith Est.


Recall that the goal of the attacker may be speed rather than e.ciency.

the attacker may not be interested in .nding all servers, but .nding a subset of them very quickly.


We assume that service providers have a PKI infrastructure that allows them to issue users signed transaction receipts.

we assume that each service provider is associated with apairofkeys(KPriv, KPub)where KPriv is the private key used to sign the transaction receipts and KPub is thepublickeyusedby other serviceproviders to verify authenticity andintegrity of receipts.


Consider the term f =((Manager 8 Accountant 8 Treasurer) n(Clerk n¬{Alice , Bob})+) and the con.guration (U = {Alice , Bob, Carl, Doris, Elaine, Frank }, UR),inwhich UR is such that: UManager = {Alice , Doris, Elaine} UAccountant = {Doris, Frank } UTreasurer = {Bob, Carl, Doris} UClerk = {Alice , Bob, Carl, Doris, Frank }.

the sub-term (Clerk n¬{Alice , Bob})+ means that only subsets of {Carl,Doris,Frank }may satisfy f.We have S(U,UR)(f)= {{Doris}, {Carl, Doris}, {Doris, Frank }, {Carl, Doris, Frank }} there are four usersets that satisfy the term f. 2.3 Algebraic Properties We now introduce the notion of equivalence among terms, which enables us to study the algebraic properties of the operators in the algebra.


Otherwise, in the worst case, ic appears in two branch queries and one condition query.

there are at least one condition query and at least two branch queries for which ic does not appear as location tags.


For the OR combination, results are shown in Figure 7(b) (in Appendix), we observed, as expected, the opposite effect on the combined results.

resulting IPR andFAR behave accordinglyto Equation5and Equation6, respectively.


For this reason, social engineers take care not to burn their sources.

they remain anonymous and cover their trails as best they can to prevent detection.


That is, the set I is the set of all path patterns based on spatial identi.ers in I.

the empty path pattern is denoted by E. Given a relational structure G .


Although security analysis of application-level software, to uncover program design .aws, has been well-explored in the academic literature [19, 17], little attention has been paid to embedded software.

embedded programs interact directly with hardware components in their surrounding circuitry, thus creating potential information-.ow pathways that traditional software analysis techniques [21] do not consider.


Thus, we assign a key to each row, and this turns the problem into a problem with a single parameter.

now the only parameter that can change is the number of rows in user rectangle R. This makes it possible to apply the techniques of [4] to solve the problem.


The question in this paper is whether we can develop a fundamental approach that can eliminate the need for .negrained policy speci.cation.

can we identify a problem whose solution results in secure functionality with little or no guidance, as is the case in memory management?


By contrast, it appears that human name pairs carry about 20 bits of entropy.

they don t have enough bits to identify even the fraction of the world that is already on the Internet.


Firstly, security properties of a network and hosts allow us to conjecture the probability that a host hj is chosen or compromised as the next target, when the attacker resides in hi.

network access control policies as well as the running services and vulnerabilities of hj allow us to predict how attractive a target such as hj would be to an attacker in hi.


This process continues until all the guesses in D5 are ordered and tested.

guesses in a dictionary D5 are tested according to their priority values, from low to high.


If these two nodes are in different deployment groups, the path key establishment only involves those in the same deployment group with the source node or the destination node.

the communication is limited in two deployment groups.


To solve the contradiction between the fundamental importance of the order of the rules and assumptions of their arbitrary add the automatic rules ordering in the list is used.

a certain order of law supports when you add any new rules or delete existing ones.


We also show that the communication complexity of our construction is nearly optimal.

we show that given an optimal solution for consensus, our construction yields a solution for GKE that uses only O(n2)messages and Copyright 2004 ACM 1-58113-802-4/04/0007 ...$5.00.