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In this paper we analyze the use of different types of statistical tests for the correlation of anomaly detection alerts. We show that the Granger Causality Test, one of the few proposals that can be extended to the anomaly detection domain, strongly depends on good choices of a parameter which proves to be both sensitive and difficult to estimate. We propose a different approach based on a set of simpler statistical tests, and we prove that our criteria work well on a simplified correlation task, without requiring complex configuration parameters. [ABSTRACT FROM AUTHOR]

Since the millennium, a quickly increasing number of research papers in the field of "computational trust and reputation" have appeared in the Computer Science literature. However, it remains hard to compare and evaluate the respective merits of proposed systems. We argue that rigorous use of formal probabilistic models enables the clear specification of the assumptions and objectives of systems, which is necessary for comparisons. To exemplify such probabilistic modeling, we present a simple probabilistic trust model in which the system assumptions as well as its objectives are clearly specified. We show how to compute (in this model) the so-called predictive probability: The probability that the next interaction with a specific principal will have a specific outcome. We sketch preliminary ideas and first theorems indicating how the use of probabilistic models could enable us to quantitatively compare proposed systems in various different environments. [ABSTRACT FROM AUTHOR]

Organisations want nowadays more controlled processes and easily usable solutions, but achieving them requires winning many challenges. Radio Frequency Identification (RFID) based technology has been proposed for improving mobile solution workflows and usability. NFC (Near Field Communication) technology is based on integrating RFID on mobile devices. This paper identifies how NFC based systems could be used to improve mobile solution workflows and usability. The results of this study are based on the implementation of six pilot cases in 2005-2007. This paper concludes that use of NFC provides both advantages and disadvantages and, therefore, to estimate the potential of NFC, its pros and cons have to be weighed up for each case in question. This paper also concludes that only a comprehensive solution achieves the full potential of NFC from users' point of view. Considering mobile solution usability, this paper concludes that NFC based solutions are easy to use, but the small and limited keyboard of mobile devices poses challenges to the design of these solutions. NFC use poses new organizational challenges like need for the rest of the system to catch up and feeling of distrust from the user side. [ABSTRACT FROM AUTHOR]

The digital watermark is used for detection of digital image alteration. However, most of digital images are printed on the paper document for submitting. Once digital images are printed on the paper, it is hard to detect alteration of it. In this paper, the detection method of printed image alteration by using digital watermark is proposed. [ABSTRACT FROM AUTHOR]

In this paper we introduce the problem of watermark security for systems in which an implementation of a watermark detector is available to an attacker. This paper serves as an introduction to a keynote talk at IWDW 2006. This talk will review two homomorphic encryption methods, viz. Paillier and Goldwasser & Micali, and their application to secure detection of Quantization Index Modulation (QIM) watermarks. [ABSTRACT FROM AUTHOR]

The virtual region-based P2P architecture was provided in this paper, which extended the proximity concept in overlay network. By virtual region it meant various related factors should be integrated into the design of P2P topology, such as peer interest, peer locality, and heterogeneity in peer capacity etc. But, the shared contents in P2P are vast and miscellaneous, it is very difficult to recognize the interest similarity among peers, dynamically form the interest region and direct peer to appropriate interest region. In this paper, the Jensen-Shannon Divergence (JSD) was used to characterize interest/semantic similarity among peers, and the interest region formation and location mechanism based on Dynamic Interest Landmark (DIL) was offered to facilitate to dynamically guide peers to join the appropriate interest region corresponding to peers' content semantic. Considering that interest region is composed of geographically sporadic peers, each interest region was organized according to peer proximity in underlying infrastructure. The theoretical and simulated results illustrated that our architecture can significantly reduce the query overhead, and improve the search performance. [ABSTRACT FROM AUTHOR]

With new channels and devices based on ubiquitous computing, UCommerce provides an environment where buyers and sellers are literally able to commerce anytime, anywhere, and anyway they like. In U-Commerce, a lot of opportunities are expectable in various industrial areas, and especially in insurance industry. In this paper, we propose new types of insurance services in U-Commerce. And as a new channel to practice it, we propose Well-Bing Store with three concepts: ‘Corporeal Insurance Product', ‘U-Cart', and ‘Health Examination'. And supportive processes in Well-Being Store are depicted in detail as well. By introducing Well-Being Store, we transform a physical place into an intelligent space which cares insured customers previously before they get sick. This is actualized by managing a list of foodstuffs in a U-Cart accordingly, and by keeping a health examination regularly with help of an insurance company and a hospital. [ABSTRACT FROM AUTHOR]

Access structure is a flexible mechanism for representing complex access control and authorization policies [1]. Numerous efforts have been devoted to the research of efficient schemes for implementing access structures in a scalable manner. Threshold closure was invented as an efficient way to implement access structures that represent complex authorization policies [4]. In essence, threshold closure is an efficient and scalable implementation of access structure using a reduced collection of threshold schemes [5]. A practical application of threshold closure was presented in [6] where the use of threshold closure for addressing the complex security needs of Grid Computing Systems was explained. One major deficiency of threshold closure is that a threshold closure generated from the corresponding access structure is not minimal in size, thus the collection of threshold schemes is not optimized for efficiency. In this connection, an operation called minimal covering was proposed to minimize the size of a threshold closure once it is formed from its corresponding access structure [4]. Unfortunately, the minimal covering of a threshold closure is no longer a threshold closure, thus is not scalable in terms of addition/deletion of access control rules. This paper presents a way for constructing minimal threshold closure. It defines a new structure called enhanced threshold closure. The paper proves that the enhanced threshold closure of an access structure is a threshold closure and is minimal, hence it is also called a minimal threshold closure. The paper also presents a mechanism for constructing minimal threshold closure from a basis access structure. Keywords: Access Control, Authorization, Threshold Schemes, Threshold Closure. [ABSTRACT FROM AUTHOR]

In this paper, we propose Cloak—a new class of reliable timing channels—which is fundamentally different from other timing channels in several aspects. First, Cloak encodes a message by a unique distribution of N packets over X TCP flows. The combinatorial nature of the encoding methods increases the channel capacity largely with (N,X). Second, Cloak offers ten different encoding and decoding methods, each of which has a unique tradeoff among several important considerations, such as channel capacity and the need for packet marking. Third, the packet transmissions modulated by Cloak could be carefully crafted to mimic the normal TCP flows in a typical TCP-based application session. Although Cloak's basic idea is simple, we show in this paper how we tackle a number of challenging issues systematically. Our experiment results collected from PlanetLab nodes and a test bed suggest that Cloak is feasible under various network conditions and different round-trip delays. [ABSTRACT FROM AUTHOR]

In this paper we design renewable traitor tracing scheme for anonymous attack. When pirated copies of some copyrighted content or content decrypting key are found, a traitor tracing scheme could identify at least one of the real users (traitors) who participate in the construction of the pirated content/key. When traitors are identified, the renewable scheme can revoke and exclude the decryption keys used by the traitors during piracy. Moreover, the revocation information included in the newly released content needs not only to disallow traitors to playback the new content, but also provide new tracing information for continuous tracing. This trace-revoke-trace system is the first such system for anonymous attack. It poses new challenges over the trace-revoke system that has extensively studied in the literatures for the pirate decoder attack. We hope the technologies described in this paper can shed new insights on future directions in this area for academia research. [ABSTRACT FROM AUTHOR]

The paper explores one of the graphical authentication techniques as the possible solution to the most important problems of traditional passwords. The aim of this work is to bring together the technical (cryptological) and non-technical (psychological) awareness into the research on passwords (click passwords in this case). Security issues of any authentication mechanism (relying on knowledge) should not be considered without analysis of the human factor − since the users' human nature was identified as a source of major weaknesses of conventional authentication. The paper deals with techniques which reduce password space and make passwords guesses feasible. Four types of pictures areas (of graphical interfaces) were investigated in order to bring to light common vulnerabilities − three of them were identified as types, which the graphical keypads should avoid. Statistics exposing strong tendentiousness in click passwords selection were presented as well. Furthermore, the paper presents a discussion on several issues of title authentication with regard to traditional passwords and other graphical techniques. [ABSTRACT FROM AUTHOR]

This paper describes an identification and authentication protocol for RFID tags with two contributions aiming at enhancing the security and privacy of RFID based systems. First, we assume that some of the servers storing the information related to the tags can be compromised. In order to protect the tags from potentially malicious servers, we devise a technique that makes RFID identification server-dependent, providing a different unique secret key shared by each pair of tag and server. The proposed solution requires the tag to store only a single secret key, regardless of the number of servers, thus fitting the constraints on tag's memory. Second, we provide a probabilistic tag identification scheme that requires the server to perform simple bitwise operations, thus speeding up the identification process. The proposed tag identification protocol assures privacy, mutual authentication and resilience to both DoS and replay attacks. Finally, each of the two schemes described in this paper can be independently implemented to enhance the security of existing RFID protocols. [ABSTRACT FROM AUTHOR]

In recent years, web applications have become tremendously popular, and nowadays they are routinely used in security-critical environments, such as medical, financial, and military systems. As the use of web applications for critical services has increased, the number and sophistication of attacks against these applications have grown as well. Most approaches to the detection of web-based attacks analyze the interaction of a web application with its clients and back-end servers. Even though these approaches can effectively detect and block a number of attacks, there are attacks that cannot be detected only by looking at the external behavior of a web application. In this paper, we present Swaddler, a novel approach to the anomaly-based detection of attacks against web applications. Swaddler analyzes the internal state of a web application and learns the relationships between the application's critical execution points and the application's internal state. By doing this, Swaddler is able to identify attacks that attempt to bring an application in an inconsistent, anomalous state, such as violations of the intended workflow of a web application. We developed a prototype of our approach for the PHP language and we evaluated it with respect to several real-world applications. [ABSTRACT FROM AUTHOR]

In this paper we present concepts for and experiences with a Situated Public Display system deployed in a university setting. We identify the rate with which information is updated as an important property to distinguish different kinds of information. With a first slideshow based prototype it was very difficult for users to predict whether information was updated since they last looked. To solve this problem, we took a broader view and conducted a contextual inquiry to investigate how people deal with paper based posters. We deduced an information flow diagram that identifies roles of people and categories of posters and noticeboards. We identified actionables, that is, posters that offer people to take a specific action, as a special type of information to support. We identified two strategies, planning and opportunism, to deal with actionable information. We present a system using two kinds of displays, News Displays and Reminder Displays, to support both strategies. We show how auctions can be used for Reminder Displays to select those information chunks that are most important in a particular context. Finally, we present an evaluation and lessons from the deployment. [ABSTRACT FROM AUTHOR]

Coordination artifacts play a primary role in cooperation and, in particular, active artifacts allow for the development of flexible cooperative software systems. Their role with respect to ubiquitous-computing environments can be defined, exploited, and assessed according to different perspectives. This paper presents a notion of active artifact that relies on the seminal definition given in CSCW literature by Schmidt and Simone, and it is applied to a model for systems supporting ubiquitous-computing collaborative environments (CASMAS). A technique to configure and interact with such environments, i.e., the composition of devices' functionalities according to their high-level features, and services provided, is presented. A scenario is used as an in-depth example along the paper. The architecture of a system implementing the scenario using our reference middleware is presented. [ABSTRACT FROM AUTHOR]

This paper shows experimental results of the linear algebra step in the number field sieve on parallel environment with implementation techniques. We developed an efficient algorithm that shares the sum of vectors in each node, and the network structure among the nodes only requires to include a ring. We also investigated the construction of a network for the linear algebra step. The construction can be realized through switches and network interface cards, whose prices are not expensive. Moreover, we investigated the implementation of the linear algebra step using various parameters. The implementation described in this paper was used for the integer factoring of a 176 digit number by GNFS and a 274 digit number by SNFS. [ABSTRACT FROM AUTHOR]

Transforming private-key encryption schemes into public-key encryption schemes is an interesting application of program obfuscation. The idea is that, given a private-key encryption scheme, an obfuscation of an encryption program with a private key embedded is used as a public key and the private key is used for decryption as it is. The security of the resulting public-key encryption scheme would be ensured because obfuscation is unintelligible and the public key is expected to leak no information on the private key. This paper investigates the possibility of general-purpose obfuscators for such a transformation, i.e., obfuscators that can transform an arbitrary private-key encryption scheme into a secure public-key encryption scheme. Barak et al. have shown a negative result, which says that there is a deterministic private-key encryption scheme that is unobfuscatable in the sense that, given any encryption program with a private key embedded, one can efficiently compute the private key. However, it is an open problem whether their result extends to probabilistic encryption schemes, where we should consider a relaxed notion of obfuscators, i.e., sampling obfuscators. Programs obfuscated by sampling obfuscators do not necessarily compute the same function as the original program, but produce the same distribution as the original program. In this paper, we show that there is a probabilistic private-key encryption scheme that can not be transformed into a secure public-key encryption scheme by sampling obfuscators which have a special property regarding input-output dependency of encryption programs. Our intention is not to claim that the required special property is reasonable. Rather, we claim that general-purpose obfuscators for the transformation, if they exist, must be a sampling obfuscator which does NOT have the special property. [ABSTRACT FROM AUTHOR]

This paper proposes a noble RFID system architecture, named uRFID, to support application domain-independent semantic interoperability under ubiquitous environment. The objective of the uRFID is to let ubiquitous RFID applications independently use information of tags in a consistent way in a variety of application domains. Although many researches have been studying to support the RFID applications, they do not consider the aforementioned semantic inconsistency issue. The uRFID is based on the metadata registry to achieve the goal. It provides an infrastructure support for the semantic consistency and application domain-independent information utilization. As a result, it enables high quality RFID applications to be developed for ubiquitous environment. Keywords: RFID, Semantic, Consistency, Interoperability, Ubiquitous computing, Metadata register. [ABSTRACT FROM AUTHOR]

The video services of most Access Grid (AG) toolkits still only employ outdated Video Conferencing Tool to transmit real-time video, and hardly have efficacious way to mix the 3D graphics model of grid results and the live videos of AG session into one scene for grid users' collaborations. This paper introduces the research work about augmented video services (AVS) of CGAG (ChinaGrid Access Grid) based on the AG framework. It shows up a reasonable way on providing augmented video services in an advanced Access Grid environment, and also a new approach to share grid resources in Grid applications. At the end of this paper, a typical sample is given to demonstrate the capabilities of this AVS, and the result proves that it yields superior quality compared to the traditional webpage of grid portal and usual interaction modals of AG. [ABSTRACT FROM AUTHOR]

Most portal systems provide simple web services in existing web environment but cannot support semantic web environment. Moreover, current portal systems are not adequate to compose personalized services. We also need semantic portlet search methods using portlet ontology, which can support ubiquitous environment, as well as portlet API that supports users' access to u-Portals through various types of terminal equipment. This paper constructs a user-centered customized web service u-portal system that supports semantic web service search and composition through a ubiquitous portal engine. [ABSTRACT FROM AUTHOR]

In intelligent ubiquitous home environments, access control should be able to accommodate dynamic mechanism that was considered various access control components including temporal and spatial information. In this paper, we propose dynamic role based access control model can support smart and secure services suitable for intelligent ubiquitous home. The proposed model is appropriate for user-oriented service based on ubiquitous computing. In the proposed model, a permission is assigned by context information. In addition, this paper observes detailed access control procedures for service in intelligent ubiquitous home, providing use case scenarios and prototype design. [ABSTRACT FROM AUTHOR]

Steganography is the technology of hiding messages in such a way that no one except the authorized recipient knows the existence of the messages. In steganography, a message is hidden in some cover message. The larger the cover message is relative to the hidden message, the easier it is to hide the latter. When the hidden message is an image, it is difficult to hide the message into another image unless the size (in number of bits) of the hidden image is much smaller than that of the cover image. To solve this problem, this paper proposes a novel steganographic technique based on image morphing. The basic idea is to transform the hidden image into a morphing image, and use the morphing image as the stego message. The authorized recipient can recover the hidden image from the morphing image through demorphing. The morphing image can also be used directly for certain purposes. [ABSTRACT FROM AUTHOR]

In this paper joint power control and channel allocation algorithms are proposed for wireless ad hoc networks. The performances of the algorithms are evaluated in both FIFO queue system and Priority queue system. To increase network capacity with time-sensitive data transmission, we incorporate the back off scheme into these systems. Through in-depth simulations, the network throughput and the probability of successful transmission of time-sensitive traffic are examined by varying several parameters. We conclude by presenting the advantages and disadvantages of different scenarios. Keywords: power control, channel assignment, time-sensitive data, back off algorithm. [ABSTRACT FROM AUTHOR]

This paper presents IPD (intelligent pervasive middleware) that provides automatic home services (consumer electronics: TV, DVD, audio, light, and air-conditioner) for human through analysis of the biometrics and environment contexts. The IPD receives the biometrics context (pulse, facial expression and body temperature, human location in smart home and human motion) from sensor devices. We handled the context's pattern analysis in two steps. The first step selects consumer electronics (TV, DVD, audio, air-conditioner, light, project) from IPD's rules. In the second step, IPD predicts detailed home service (for example, a detailed home service of the TV includes news, sports, and drama), using the supervised algorithm-based pattern analyzer. We used the SVM (support vector machine) for detailed service pattern analysis. We experimented on the intelligent pervasive middleware in two directions, and it was shown to have an effective performance in practical application. We are currently studying the association technique of home service (by using data mining) that can happen when IPD predicts home service by the home service predictor. Keywords: Biometrics, Smart Home, Intelligent Home, Pattern Recognition. [ABSTRACT FROM AUTHOR]

This paper presents a smart identification card system using facial biometric information for identity authentification. For a trade-off between the security and the cost, this system utilizes an architecture containing three security levels of identity authentification, "manual face verification offline", "manual face verification online" and "automatic (biometric) face verification", which satisfy the different security requirements of various applications of identification cards. For the function of "manual face verification online", we bring out an idea based on decomposing the face image into two parts which are stocked into the card and the database of system respectively. And for the function of "automatic face verification", we proposed a novel face verification scheme based on class-specific face models. The technique Active Appearance Model is applied, as the way of face modelling, to realize the proposed scheme. A prototype application of such system, which contains a fix version for PC and a mobile version for Pocket PC, is also introduced in this paper. [ABSTRACT FROM AUTHOR]

Logistics has become a fast growing industry in recent years. In particular, the large hub ports have heavy congestions in getting the containers in and out of the ports. Therefore the ports are regarded as the bottleneck in the logistics. In this paper, we analyze the new requirements of port logistics to figure out heavy congestions and then present the system prototype for identification and positioning or tracking in the port environments. Our solution is composed of three parts: RFID, electronic container seal, and RTLS system. The system design focuses on three parts: 1) the standard compliance with the ISO, 2) the energy saving mechanism to maintain the longevity of tags as long as possible, and 3) the high identification rate in the presence of multiple tags. The performance evaluation of the system is also included in the paper. These systems will provide a complete range of port logistics services. [ABSTRACT FROM AUTHOR]

Many wall-size display systems are built to provide large-scale visualization. These systems may be quite successful for some limited applications, but are very inflexible, since these systems only have fixed display regions. This paper integrates steerable projectors whose beam can be moved under computer control onto a wall-size display system to strengthen its display ability. With the steerable projectors, the integrated display system, named Flexible Display, provide an extendable display region. This consists of a large-scale display region and several movable display regions, such that the integrated display system has great potential in the area of human-computer interaction and information visualization. This paper applies the Flexible Display to a virtual museum application to give the users fluent navigation experience. For the application, the Flexible Display provides the following functions: 1) intensity and resolution enhancement of sub-region of display wall, 2) information augmentation, and 3) "stepping user interfaces" for its viewers interacting with display wall. [ABSTRACT FROM AUTHOR]

One of the challenges for ubiquitous computing is to design systems that can be both understood by their users and at the same time understand the users themselves. As information and its meaning becomes more associated with the communities that provide and use it, how will it be possible to build effective systems for these users? We have been examining these issues via ethnographic analysis of the information and community supporting system that we have developed and employed at conference events. This paper presents initial analysis and suggests greater focus on the interaction between members of micro-communities of users in future ubicomp research. [ABSTRACT FROM AUTHOR]

Over the last decade, new information and communication technologies have lived a secret life. For individuals and institutions around the world, this constellation of mobile phones, personal computers, the internet, software, games, and other computing objects have supported a complex set of religious and spiritual needs. In this paper, I offer a survey of emerging and emergent techno-spiritual practices, and the anxieties surrounding their uptake. I am interested in particular in the ways in which religious uses of technology represent not only a critique of dominant visions of technology's futures, but also suggest a very different path(s) for ubiquitous computing's technology envisioning and development. [ABSTRACT FROM AUTHOR]

P3P allows Web sites to declare their intentions in a standard form (as a policy) in so far as privacy related matters are concerned. User agents are free to then examine P3P policies prior to engaging in normal interactions with a Web server (upon which the Web site is hosted). Unsuitable policies may result in no further interactions with the Web server. Since P3P was designed with only two parties in mind (the client and the server), the presence of a Web Proxy in the P3P framework raises privacy concerns that demand attention. What is immediately apparent is the problem of a user accessing a site with an acceptable P3P policy via a Proxy which may employ a privacy policy that is unacceptable to the user. In this paper we discuss some of these problems within the context of a P3P environment. In discussing these problems we focus our attention on the identification of a Proxy within a P3P environment and the separation of a Proxy's policy from the policy of a site being accessed through it. [ABSTRACT FROM AUTHOR]

This paper presents a framework that employs security ontologies and security patterns to provide application developers with a way to utilize security expertise. Through the development of a security ontology, developers locate the major security-related concepts relevant to their application context. Security patterns are then integrated with these concepts to provide tested solutions for accommodating security requirements. [ABSTRACT FROM AUTHOR]

Privacy management is important for enterprises that collect, store, access and disclose personal data. Among other things, the management of privacy includes dealing with privacy obligations that dictate duties and expectations an enterprise has to comply with, in terms of data retention, deletion, notice requirements, etc. This is still a green area open to research and innovation: it is about enabling privacy-aware information lifecycle management. This paper provides an overview of the work we have done in this space: definition of an obligation management model and a related framework; implementation of a prototype of an obligation management system integrated both in the context of the PRIME project and with an HP identity management solution. This paper then focuses on an important open issue: how to make our approach scalable, in case large amounts of personal data have to be managed. Thanks to our integration work and the feedback we received, we learnt more about how users and enterprises are likely to deal with privacy obligations. We describe these findings and how to leverage them. Specifically, in the final part of this paper we introduce and discuss the concepts of parametric obligation and "hybrid" obligation management and how this can improve the scalability and flexibility of our system. Our work is in progress. Further research and development is going to be done in the context of the PRIME project and an HP Labs project. [ABSTRACT FROM AUTHOR]

This paper presents a Colored Petri Nets (CPN) approach to analyze the information flow in the policy file of Security-Enhanced Linux (SELinux). The SELinux access control decisions are based on a security policy file that contains several thousands of security rules. It becomes a challenge for policy administrator to determine whether the modification of the security policy file conforms to the pre-specified security goals. To address this issue, this paper proposes a formal information flow model for SELinux security policy file, and presents a simple query language to help administrators to express the expected/unexpected information flow. We developed a method to transform the SELinux policy and security goal into Policy CPN Diagram and Query CPN Diagram. A tool named SEAnalyzer that can automatically verify the SELinux policy has been developed and two application examples of this tool will be presented in the context. Keywords: Colored Petri Nets, information flow, SELinux, security policy. [ABSTRACT FROM AUTHOR]

This position paper discusses the relation of privacy, namely pseudonymity, to evidence-based trust (or rather reputation). Critical concepts of evidence-based trust/reputation systems are outlined first, followed by an introduction to the four families of the Common Criteria (for security evaluation) Privacy Class: Unobservability, Anonymity, Unlinkability, and Pseudonymity. The paper then discusses the common problem of many papers that narrow the considerations of privacy to anonymity only, and elaborates on the concept of pseudonymity through aspects of evidence storing, attacks and some of their implications, together with other related issues like use of mixes. [ABSTRACT FROM AUTHOR]

In this paper, we present a security framework that provides identity protection against active and passive attacks for end-points. The framework is based on a two-round-trip authenticated Diffie-Hellman key exchange protocol that identifies the end-points to each other and creates a security association between the peers. The protocol hides the public key based identifiers from attackers and eavesdroppers by blinding the identifiers. We complete the identity protection by offering location privacy with forwarding agents. To our knowledge, our privacy enhanced protocol is the first denial-of-service resistant two-round-trip key exchange protocol that offers identity protection for both communicating peers. [ABSTRACT FROM AUTHOR]

In keeping with the tradition of this workshop this is actually a position paper in the sense that it represents work that's not done and ideas for work that could be done, rather than simply a paper that got rejected from a bunch of other conferences. [Laughter] [ABSTRACT FROM AUTHOR]

This paper identifies certain privacy threats that apply to anonymous credential systems. The focus is on timing attacks that apply even if the system is cryptographically secure. The paper provides some simple heuristics that aim to mitigate the exposure to the threats and identifies directions for further research. Keywords: anonymous credential systems, pseudonym systems, unlinkability, privacy, timing attacks. [ABSTRACT FROM AUTHOR]

Cheating in secret sharing has been considered in several papers. Recently cheating in visual cryptography has been considered in [10], where (2,n)-threshold visual cryptography schemes are provided. In this paper we provide new (2,n)-threshold visual cryptography schemes. Our model is different from the one considered in [10]; in particular we aim at constructing cheating immune schemes without the use of extra information, like additional shares or images as done in [10]. We have provided a formal definition of cheating which requires that a group of cheaters be able to deterministically force a honest participant to reconstruct a wrong secret. The (2,n)-threshold schemes that we provide do not allow such cheating, regardless of the number of cheaters. [ABSTRACT FROM AUTHOR]

One of the most basic requirements concerning Boolean functions used in cryptosystems is that they must have high algebraic degrees. This simple criterion is not always well adapted to the concrete situation in which Boolean functions are used in symmetric cryptography, since changing one or several output bits of a Boolean function considerably changes its algebraic degree while it may not change its robustness. The proper characteristic is the r-th order nonlinearity profile (which includes the first-order nonlinearity). However, studying it is difficult and almost no paper, in the literature, has ever been able to give general effective results on it. The values of the nonlinearity profile are known for very few functions and these functions have little cryptographic interest. A recent paper has given a lower bound on the nonlinearity profile of functions, given their algebraic immunity. We improve upon it, and we deduce that it is enough, for a Boolean function, to have high algebraic immunity, for having non-weak low order nonlinearity profile (even when it cannot be evaluated), except maybe for the first order. Keywords: stream cipher, block cipher, algebraic attack, Boolean function, algebraic immunity, algebraic degree, higher order nonlinearity. [ABSTRACT FROM AUTHOR]

Spitzner proposed to classify honeypots into low, medium and high interaction ones. Several instances of low interaction exist, such as honeyd, as well as high interaction, such as GenII. Medium interaction systems have recently received increased attention. ScriptGen and RolePlayer, for instance, are as talkative as a high interaction system while limiting the associated risks. In this paper, we do build upon the work we have proposed on ScriptGen to automatically create honeyd scripts able to interact with attack tools without relying on any a-priori knowledge of the protocols involved. The main contributions of this paper are threefold. First, we propose a solution to detect and handle so-called intra-protocol dependencies. Second, we do the same for inter-protocols dependencies. Last but not least, we show how, by modifying our initial refinement analysis, we can, on the fly, generate new scripts as new attacks, i.e. 0-day, show up. As few as 50 samples of attacks, i.e. less than one per platform we have currently deployed in the world, is enough to produce a script that can then automatically enrich all these platforms. [ABSTRACT FROM AUTHOR]

As Structured Peer-to-Peer (P2P) Networks become popular, there is an emerging need to monitor continuously the huge number of participants in a robust and scalable manner. To this end, aggregation has emerged as a basis for the self-management of these networks. However, the structured P2P networks lack today of efficient mechanisms for the decentralized computation of these aggregates. In this paper, we propose a hierarchical theoretic model based on Cayley Graphs, which overcomes the requisite to accommodate growth without impacting the efficiency of distributed applications. Also, the paper presents an aggregation protocol that fuses the fault-resilience of gossip algorithms with the scalability of trees. In particular, simulation results show that this algorithm is capable to cope with the distributed and unreliable nature of P2P networks. Keywords: Structured P2P Networks, DHT, Aggregation, Hierarchical model, Gossip, Cayley Graphs. [ABSTRACT FROM AUTHOR]

In this paper we propose a robust software watermarking based on chaos against several limitations of existing software watermarking. The algorithm combines the anti-reverse engineering technique, chaotic system and the idea of Easter Egg software watermarks. The global protection for the program is provided by dispersing watermark over the whole code of the program with chaotic dispersion coding; the resistance against reverse engineering is improved by using the anti-reverse engineering technique. In the paper, we implement the scheme in the Intel i386 architecture and the Windows operating system, and analyze the robustness and the performance degradation of watermarked program. Analysis indicates that the algorithm resists various types of semantics-preserving transformation attacks and is good tolerance for reverse engineering attacks. [ABSTRACT FROM AUTHOR]

In this paper we focus on the use of a traitor tracing scheme for distribution models that are one-to-many. It can be a networked broadcast system; It can be based on prerecorded or recordable physical media. In this type of system, it is infeasible to mark each copy differently for each receipt. Instead, the system broadcasts limited variations at certain points, and a recipient device has the cryptographic keys that allow it to decrypt only one of the variations at each point. Over time, when unauthorized copies of the protected content are observed, a traitor tracing scheme allows the detection of the devices that have participated in the construction of the pirated copies. The authors have been involved in what we believe is the first large-scale deployment of the tracing traitors approach in a content protection standard for the new generation of high-definition DVD optical discs. Along the way, we have had to solve both practical and theoretical problems that had not been apparent in the literature to date. In this paper we will mainly present this state of practice of the traitor tracing technology and show some of our experience in bringing this important technology to practice. [ABSTRACT FROM AUTHOR]

Recently, the security threat on web application is increasing rapidly and especially open source web applications are becoming popular target of web server hacking. And more there was a worm which spread via web application vulnerabilities. Web application attack uses the vulnerability not in web server itself, but in structural, logical, and code errors. The majority of flaws in web applications are caused by absence of the user input validation. But, it is difficult to detect various abnormal user inputs by pattern matching method. In this paper, we propose the web application securing proxy based on profiling which can be constructed by learning usual normal activity. The proposed proxy system can detect and filter out attacker's abnormal requests via anomaly detection mechanism. Keywords: Web application, Anomaly detection, Hacking, Proxy. [ABSTRACT FROM AUTHOR]

With the wide implementations of Role-based access control (RBAC) models in the information systems, the access control for RBAC itself, administration of RBAC, becomes more and more important. In this paper, we propose a Domain Administration of RBAC Model, DARBAC, which defines an administrative domain for each administrative role. The administrative role can execute administrative operations on the users, roles, objects and child administrative roles within its administrative domain. Then we use π-calculus to formalize the elements of DARBAC model and their interactions. Although π-calculus has been successfully used in many security areas such as protocol analysis and information flow analysis, as we have known, our approach is the first attempt to use π-calculus to formalize RBAC and its administrative model. [ABSTRACT FROM AUTHOR]

The anti-spoofing community has been intensively proposing new methods for defending against new spoofing techniques. It is still challenging for protecting naïve users from advanced spoofing attacks. In this paper, we analyze the problems within those anti-spoofing mechanisms and propose a new Automatic Detecting Security Indicator (ADSI) scheme. This paper describe the trust model in ADSI in detail firstly. In a secure transaction, ADSI may generate a random picture and embed it into the current web browser. This can be triggered by any security relevant event occurred on the browser, and then performs automatic checking on current active security status. When a mismatch of embedded images is detected, an alarm goes off to alert the users. Since an adversary is hard to replace or mimic the randomly generated picture, the web-spoofing attack can not be mounted. In comparison with existing proposals, our scheme has the weakest security assumption and places a very low burden on the computer by automating the process of detection and recognition of the web-spoofing for SSL-enabled communication. Moreover, this scheme has little intrusive on the browser. Finally, this scheme can be implemented in trusted PC at Internet Cafe requiring neither Logo Certification Authority, nor the scheme of personalization. Keywords: Web Spoofing, SSL, Automatic Detecting Security Indicator. [ABSTRACT FROM AUTHOR]

Comb method is an efficient method to calculate point multiplication in elliptic curve cryptography, but vulnerable to power-analysis attacks. Various algorithms have been proposed recently to make the comb method secure to power-analysis attacks. In this paper, we present an efficient comb method and its Simple Power Analysis (SPA)-resistant counterpart. We first present a novel comb recoding algorithm which converts an integer to a sequence of signed, MSB-set comb bit-columns. Using this recoding algorithm, the signed MSB-set comb method and a modified, SPA-resistant version are then presented. Measures and precautions to make the proposed SPA-resistant comb method resist all power-analysis attacks are also discussed, along with performance comparison with other comb methods. We conclude that our comb methods are among the most efficient comb methods in terms of number of precomputed points and computational complexity. [ABSTRACT FROM AUTHOR]

In Crypto 2000 and 2003, Lenstra-Verheul and Rubin- Silverberg proposed XTR public key system and torus based public key cryptosystem CEILIDH, respectively. The common main idea of XTR and CEILIDH is to shorten the bandwidth of transmission data. Due to the contribution of Granger et al., that is the comparison result of the performance of CEILIDH and XTR, XTR is an excellent alternative to either RSA or ECC in some applications, where computational power and memory capacity are both very limited, such as smart-cards. Among the family of XTR algorithm, Improved XTR Single Exponentiation (XTR-ISE) is the most efficient one, which computes single exponentiation. However, there are few papers investigating the side channel attacks of XTR-ISE, even though the memory constraint devices suffer most from vulnerability to side channel attacks. Chung-Hasan and Page-Stam tried to analyze XTR-ISE with the known simple power analysis, but unfortunately their approach were not practically feasible. Recently, Han et al. proposed new collision attack on it with analysis complexity O(240) when the key size is 160-bit. In this paper we analyze XTR-ISE from other point of view, namely differential power analysis (DPA). One straightforward result is that XTR-ISE can be free from the original DPA. However, a non-trivial result is that an enhancing DPA proposed in this paper threatens XTR-ISE. Furthermore, we show several weak points of the structure of XTR-ISE. From our simulation results, we show the proposed attack requires about 584 times queries to DPA_Oracle to detect the whole 160-bit secret value. This result shows that XTR-ISE is vulnerable to the proposed enhancing DPA. Keywords:XTR public key system, XTR-ISE, differential power analysis. [ABSTRACT FROM AUTHOR]

Nowadays, security solutions are mainly focused on providing security defences, instead of solving one of the main reasons for security problems that refers to an appropriate Information Systems (IS) design. In fact, requirements engineering often neglects enough attention to security concerns. In this paper it will be presented a case study of our proposal, called SREP (Security Requirements Engineering Process), which is a standard-centred process and a reuse-based approach which deals with the security requirements at the earlier stages of software development in a systematic and intuitive way by providing a security resources repository and by integrating the Common Criteria into the software development lifecycle. In brief, a case study is shown in this paper demonstrating how the security requirements for a security critical IS can be obtained in a guided and systematic way by applying SREP. [ABSTRACT FROM AUTHOR]

This paper proposes a practical fault attack on two asynchronous DES crypto-processors, a reference version and a hardened version, using round reduction. Because of their specific architecture, asynchronous circuits have a very specific behavior in the presence of faults. Previous works show that they are an interesting alternative to design robust systems. However, this paper demonstrates that there are weaknesses left, and that we are able both to identify and exploit them. The effect of the fault is to reduce the number of rounds by corrupting the multi-rail round counter protected by alarm cells. The fault injection mean is a laser. A description of the fault injection process is presented, followed by how the results can be used to retrieve the key. Weaknesses are theoretically identified and analyzed. Finally, possible counter-measures are described. [ABSTRACT FROM AUTHOR]