waashk/dblp huggingface dataset:
bind: a fine-grained attestation service for secure distributed systems. in this paper, we propose bind (binding instructions and data), a fine-grained attestation service for securing distributed systems. code attestation has recently received considerable attention in trusted computing. however, current code attestation technology is relatively immature. first, due to the great variability in software versions and configurations, verification of the hash is difficult. second, the time-of-use and time-of-attestation discrepancy remains to be addressed, since the code may be correct at the time of the attestation, but it may be compromised by the time of use. the goal of bind is to address these issues and make code attestation more usable in securing distributed systems. bind offers the following properties: 1) bind performs fine-grained attestation. instead of attesting to the entire memory content, bind attests only to the piece of code we are concerned about. this greatly simplifies verification. 2) bind narrowsthe gap between time-of-attestation and time-of-use. bind measures a piece of code immediately before it is executed and uses a sand-boxing mechanism to protect the execution of the attested code. 3) bind ties the code attestation with the data that the code produces, such that we can pinpoint what code has been run to generate that data. in addition, by incorporating the verification of input data integrity into the attestation, bind offers transitive integrity verification, i.e., through one signature, we can vouch for the entire chain of processes that have performed transformations over a piece of data. bind offers a general solution toward establishing a trusted environment for distributed system designers.
recent advances in the design and implementation of large integer factorization algorithms. the latest and possibly fastest of the generalfactoring methods for large composite numbers is thequadratic sieve of carl pomerance. a variation ofthe algorithm is described and an implementation issuggested which combines the forces of a fast pipelinecomputer such as the cray i, and a high speedhighly parallel array processor such as the goodyearmpp. a running time analysis, which is based onempirical data rather than asymptotic estimates,suggests that this method could be capable offactoring a 60 digit number in as little as 10minutes and a 100 digit number is as little as 60days of continuous computer time.
a generic attack on checksumming-based software tamper resistance. self-checking software tamper resistance mechanisms employing checksums, including advanced systems as recently proposed by chang and atallah (2002) and horne et al. (2002), have been promoted as an alternative to other software integrity verification techniques. appealing aspects include the promise of being able to verify the integrity of software independent of the external support environment, as well as the ability to automatically integrate checksumming code during program compilation or linking. in this paper, we show that the rich functionality of many modern processors, including ultrasparc and x86-compatible processors, facilitates automated attacks which defeat such checksumming by self-checking programs.
extended abstract: forward-secure sequential aggregate authentication. wireless sensors are employed in a wide range of applications. one common feature of many sensor settings is the need to communicate sensed data to some collection point or sink. this communication can be direct (to a mobile collector) or indirect - via other sensors towards a remote sink. in either case, a sensor might not be able to communicate to a sink at will. instead it might collect data and wait (for a potentially long time) for a signal to upload accumulated data directly. in a hostile setting, a sensor may be compromised and its post-compromise data can be manipulated. one important issue is forward security - how to ensure that precompromise data cannot be manipulated? since a typical sensor is limited in storage and communication facilities, another issue is how to minimize resource consumption by accumulated data. it turns out that current techniques are insufficient to address both challenges. to this end, we explore the notion of forward-secure sequential aggregate (fssagg) authentication schemes. we consider fssagg authentication schemes in the contexts of both conventional and public key cryptography and construct a fssagg mac scheme and a fssagg signature scheme, each suitable under different assumptions. this work represents the initial investigation of forward-secure aggregation and, although the proposed schemes are not optimal, we believe it opens a new direction for follow-on research.
accurate real-time identification of ip prefix hijacking. we present novel and practical techniques to accurately detect ip prefix hijacking attacks in real time to facilitate mitigation. attacks may hijack victim's address space to disrupt network services or perpetrate malicious activities such as spamming and dos attacks without disclosing identity. we propose novel ways to significantly improve the detection accuracy by combining analysis of passively collected bgp routing updates with data plane ingerprints of suspicious prefixes. the key insight is to use data plane information in the form of edge network ingerprinting to disambiguate suspect ip hijacking incidences based on routing anomaly detection. conflicts in data plane ingerprints provide much more definitive evidence of successful ip pre- fix hijacking. utilizing multiple real-time bgp feeds, we demonstrate the ability of our system to distinguish between legitimate routing changes and actual attacks. strong correlation with addresses that originate spam emails from a spam honeypot confirms the accuracy of our techniques.
verification of treaty compliance revisited. in a series of papers, the author has documentedthe evolution at the sandia national laboratoriesof a solution to the problem of how two mutuallydeceitful and distrusting parties -- the hostand the monitor -- can both trust a data acquisitionsystem whose function is to inform the monitor,and perhaps third parties, whether the hosthas or has not violated the terms of a treaty. thenational interests of the various participants,host, monitor and third parties, at first appear tobe mutually irreconcilable, however the conclusionof this paper will be that it is possible to simultaneouslysatisfy the interests of all parties. thetechnical device on which this fourth, and hopefullyfinal, iteration of treaty verification systemsis based is the concatenation of two or moretwo key cryptographic systems. in the resultingsystem no part of the rneasage need be kept secretfrom any participant at anytime; no party, nor collusionof fewer than all of the parties can utteran undetectable forgery;no unilateral action onthe part of any party can lessen the confidence ofthe others as to the authenticity of the data andfinally third parties can be logically persuadedof the authenticity of messages. thus, finallyafter a decade of development a complete technicalsolution is in hand for the problem of the verificationof treaty compliance.
modeling security-relevant data semantics. the use of an extended data model which represents both integrity and secrecy aspects of data is demonstrated. this semantic data model for security (sdms) provides a technique that assists domain experts, security officers, and database designers in first understanding their security requirements, and then translating them into a good database design. identifying security requirements at this semantic level provides the basis for analyzing the security requirements and the database design for inference and signaling vulnerabilities. another contribution is a comprehensive taxonomy of security-relevant data semantics that must be captured and understood to implement a multilevel secure automated information system.
worm origin identification using random moonwalks. we propose a novel technique that can determine both the host responsible for originating a propagating worm attack and the set of attack flows that make up the initial stages of the attack tree via which the worm infected successive generations of victims. we argue that knowledge of both is important for combating worms: knowledge of the origin supports law enforcement, and knowledge of the causal flows that advance the attack supports diagnosis of how network defenses were breached. our technique exploits the "wide tree" shape of a worm propagation emanating from the source by performing random "moonwalks" backward in time along paths of flows. correlating the repeated walks reveals the initial causal flows, thereby aiding in identifying the source. using analysis, simulation, and experiments with real world traces, we show how the technique works against both todayýs fast propagating worms and stealthy worms that attempt to hide their attack flows among background traffic.
pi: a path identification mechanism to defend against ddos attack. distributed denial of service (ddos) attacks continueto plague the internet. defense against these attacksis complicated by spoofed source ip addresses,which make it difficult to determine a packet's true origin.we propose pi (short for path identifier), a newpacket marking approach in which a path fingerprint isembedded in each packet, enabling a victim to identifypackets traversing the same paths through the interneton a per packet basis, regardless of source ip addressspoofing.pi features many unique properties. it is a per-packetdeterministic mechanism: each packet traveling alongthe same path carries the same identifier. this allowsthe victim to take a proactive role in defending againsta ddos attack by using the pi mark to filter out packetsmatching the attackers' identifiers on a per packet basis.the pi scheme performs well under large-scale ddosattacks consisting of thousands of attackers, and is effectiveeven when only half the routers in the internetparticipate in packet marking. pi marking and filteringare both extremely light-weight and require negligiblestate.we use traceroute maps of real internet topologies(e.g. caida's skitter [5] and burch and cheswick's internetmap [3, 14]) to simulate ddos attacks and validateour design.
expander graphs for digital stream authentication and robust overlay networks. we use expander graphs to provide efficient new constructions for two security applications: authentication of long digital streams over lossy networks and building scalable,robust overlay networks. here is a summaryof our contributions: (1) to authenticate long digital streams over lossy networks,we provide a construction with a provable lower bound on the ability to authenticate a packet and that lower bound is independent of the size of the graph.to achieve this,we present an authentication expander graph with constant degree.(previous work,such as [ms01],used authentication graphs but requir ed graphs with degree linear in the number of vertices. ) (2) to build efficient,robust,and scalable overlay networks,we provide a construction using undirected expander graphs with a provable lower bound on the ability of a broadcast message to successfully reach any receiver.this also gives us a new,more efficient solution to the decentralized certicate revocation problem [wlm00].
practical techniques for searches on encrypted data. it is desirable to store data on data storage servers such as mail servers and file servers in encrypted form to reduce security and privacy risks. however, this usually implies that one has to sacrifice functionality for security. for example, if a client wishes to retrieve only documents containing certain words, it was not previously known how to let the data storage server perform the search and answer the query without loss of data confidentiality.in this paper, we describe our cryptographic schemes for the problem of searching on encrypted data and provide proofs of security for the resulting crypto systems. our techniques have a number of crucial advantages. they are provably secure: they provide provable secrecy for encryption, in the sense that the untrusted server cannot learn anything about the plain text when only given the ciphertext; they provide query isolation for searches, meaning that the untrusted server cannot learn anything more about the plaintext than the search result; they provide controlled searching, so that the untrusted server cannot search for an arbitrary word without the user's authorization; they also support hidden queries, so that the user may ask the untrusted server to search for a secret word without revealing the word to the server. the algorithms we present are simple, fast (for a document of length $n$, the encryption and search algorithms only need o(n) stream cipher and block cipher operations), and introduce almost no space and communication overhead, and hence are practical to use today.
automatically generating malicious disks using symbolic execution. many current systems allow data produced by potentially malicious sources to be mounted as a file system. file system code must check this data for dangerous values or invariant violations before using it. because file system code typically runs inside the operating system kernel, even a single unchecked value can crash the machine or lead to an exploit. unfortunately, validating file system images is complex: they form dags with complex dependency relationships across massive amounts of data bound together with intricate, undocumented assumptions. this paper shows how to automatically find bugs in such code using symbolic execution. rather than running the code on manually-constructed concrete input, we instead run it on symbolic input that is initially allowed to be "anything." as the code runs, it observes (tests) this input and thus constrains its possible values. we generate test cases by solving these constraints for concrete values. the approach works well in practice: we checked the disk mounting code of three widely-used linux file systems: ext2, ext3, and jfs and found bugs in all of them where malicious data could either cause a kernel panic or form the basis of a buffer overflow attack.
escort: securing scout paths. abstract: scout is a communication oriented operating system that can be specialized for different information appliances. it uses paths as an explicit first class object to describe the flow of information through the system. escort is the security architecture for scout. it uses the explicit knowledge provided by a path abstraction to secure information flow in a flexible manner.
self-healing key distribution with revocation. we address the problem of establishing a group key amongst a dynamicgroup of users over an unreliable, or lossy, network.we term ourkey distribution mechanisms self-healing because users arecapable of recovering lost group keys on their own, withoutrequesting additional transmissions from the group manager, thuscutting back on network traffic, decreasing the load on the groupmanager, and reducing the risk of user exposure through trafficanalysis. a user must be a member both before and after the sessionin which a particular key is sent in order to be able to recover thekey through self-healing. binding the ability to recover keys tomembership status enables the group manager to use short broadcaststo establish group keys, independent of the group size.inaddition, the self-healing approach to key distribution isstateless, meaning that a group member who has been off-line forsome time is able to recover new session keys immediately aftercoming back on-line.
fireman: a toolkit for firewall modeling and analysis. security concerns are becoming increasingly critical in networked systems. firewalls provide important defense for network security. however, misconfigurations in firewalls are very common and significantly weaken the desired security. this paper introduces fireman, a static analysis toolkit for firewall modeling and analysis. by treating firewall configurations as specialized programs, fireman applies static analysis techniques to check misconfigurations, such as policy violations, inconsistencies, and inefficiencies, in individual firewalls as well as among distributed firewalls. fireman performs symbolic model checking of the firewall configurations for all possible ip packets and along all possible data paths. it is both sound and complete because of the finite state nature of firewall configurations. fireman is implemented by modeling firewall rules using binary decision diagrams (bdds), which have been used successfully in hardware verification and model checking. we have experimented with fireman and used it to uncover several real misconfigurations in enterprise networks, some of which have been subsequently confirmed and corrected by the administrators of these networks.
a unified scheme for resource protection in automated trust negotiation. automated trust negotiation is an approach to establishingtrust between strangers through iterative disclosure ofdigital credentials. in automated trust negotiation, accesscontrol policies play a key role in protecting resources fromunauthorized access. unlike in traditional trust managementsystems, the access control policy for a resource isusually unknown to the party requesting access to the resource,when trust negotiation starts. the negotiating partiescan rely on policy disclosures to learn each other's accesscontrol requirements. however, a policy itself may alsocontain sensitive information. disclosing policies' contentsunconditionally may leak valuable business information orjeopardize individuals' privacy. in this paper, we proposeunipro, a unified scheme to model protection of resources,including policies, in trust negotiation. unipro improves onprevious work by modeling policies as first-class resources,protecting them in the same way as other resources, providingfine-grained control over policy disclosure, and clearlydistinguishing between policy disclosure and policy satisfaction,which gives users more flexibility in expressing theirauthorization requirements. we also show that unipro canbe used with practical negotiation strategies without jeopardizingautonomy in the choice of strategy, and present criteriaunder which negotiations using unipro are guaranteedto succeed in establishing trust.
cryptovirology: extortion-based security threats and countermeasures. traditionally, cryptography and its applications are defensive in nature, and provide privacy, authentication, and security to users. in this paper we present the idea of ``cryptovirology'' which employs a twist on cryptography, showing that it can also be used offensively. by being offensive we mean that it can be used to mount extortion based attacks that cause loss of access to information, loss of confidentiality, and information leakage, tasks which cryptography typically prevents. in this paper we analyze potential threats and attacks that rogue use of cryptography can cause when combined with rogue software (viruses, trojan horses), and demonstrate them experimentally by presenting an implementation of a ``cryptovirus'' that we have tested (we took careful precautions in the process to insure that the virus remained contained). public-key cryptography is essential to the attacks that we demonstrate (which we call "cryptovirological attacks''). we also suggest countermeasures and mechanisms to cope with and prevent such attacks. these attacks have implications on how the use of cryptographic tools should be managed and audited in general purpose computing environments, and imply that access to cryptographic tools should be well controlled. the experimental virus demonstrates how cryptographic packages can be condensed into a small space, which may have independent applications (e.g., cryptographic module design in small mobile devices).
deniable password snatching: on the possibility of evasive electronic espionage. abstract: cryptovirology has recently been introduced as a means of mounting active viral attacks using public key cryptography. it has been shown to be a tool for extortion attacks and "electronic warfare", where attacks are mounted against information resources. the natural question to ask is whether cryptovirology is also useful in the area of spying via malware. we demonstrate that cryptovirology does help in "electronic espionage" and allows the spy to conceal his or her identity (as well as past collected information). specifically, we present an attack that can be mounted by a cryptotrojan that allows the attacker to gather information (passwords) from a system in such a way that the attacker cannot be proven guilty beyond reasonable doubt. that is, even if the attacker is under surveillance on the local machine from when he first attacks the target machine, to when he obtains the passwords, and even if the leaked information is made available to the attacker exclusively, he still cannot be caught. the threat is made possible by the combination of public key cryptography, probabilistic encryption, and the use of public information (i/o or communication) channels which together form a "secure receiver-anonymous channel". the machine can be standalone or networked. what we learn from the attack is extracted as general tools and basic principles for "espionage attacks".
a general theory of security properties. abstract: we present a general theory of possibilistic security properties. we show that we can express a security property as a predicate that is true of every set containing all the traces with the same low level event sequence. given this security predicate, we show how to construct a partial ordering of security properties. we also discuss information flow and present the weakest property such that no information can flow from high level users to low level users. finally, we present a comparison of our framework and mclean's (1994) selective interleaving functions framework.
using replication and partitioning to build secure distributed systems. a challenging unsolved security problem is how to specifyand enforce system-wide security policies; this problemis even more acute in distributed systems with mutual distrust.this paper describes a way to enforce policies fordata confidentiality and integrity in such an environment.programs annotated with security specifications are staticallychecked and then transformed by the compiler to runsecurely on a distributed system with untrusted hosts. thecode and data of the computation are partitioned acrossthe available hosts in accordance with the security specification.the key contribution is automatic replication ofcode and data to increase assurance of integrity-withoutharming confidentiality, and without placing undue trustin any host. the compiler automatically generates securerun-time protocols for communication among the replicatedcode partitions. results are given from a prototype implementationapplied to various distributed programs.
a fair non-repudiation protocol. abstract: a fair non-repudiation protocol should not give the sender of a message an advantage over the receiver, or vice versa. we present a fair non-repudiation protocol that requires a trusted third party but attempts to minimize its involvement in the execution of the protocol. we draw particular attention to the nonstandard use of encryption in our protocol and discuss some aspects of its formal verification.