bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion protection and antifouling properties of varnish-coated steel containing natural additive
Authors: Abd-El-Nabey Besheir , El-Housseiny Sherif , Khamis Essam , Abdel-Gaber Ashraf
Published: May 2016

The corrosion protection and antifouling properties of varnish-coated steel panels containing different amounts of cannabis extracts were investigated using electrochemical impedance spectroscopy (EIS), salt spray and immersion tests in 0.5 M NaCl solution and subjected to a field test in seawater. Analysis of the experimental data showed that the presence of cannabis extract resisted the deterioration (peeling off) tendency of the varnish-coated steel panels exposed to aggressive environments. Visual inspection showed that the cannabis extract also provided good antifouling properties.
Et le comité de direction a ri
Authors: Ayache Magali , Dumez Hervé
Published: May 2016

Beaucoup de projets de changement organisationnel échouent. L’explication traditionnelle repose sur les jeux d’acteurs (résistance au changement). Cet article propose une interprétation alternative fondée sur l’analyse de la matérialité des projets de changement (notamment les Powerpoint)vial’identification d’un mécanisme de non-changement. Le mécanisme identifié met l’accent sur le phasage des projets combiné avec la recherche dequick wins, et sur la triple tension qui caractérise les Powerpoint : les tensions descriptif/normatif, expansion/contraction, oubli/rétention.
Intégrer les émotions dans le développement de nouveaux produits
Authors: Herbeth Nathalie , Charue-Duboc Florence , Manceau Delphine
Published: May 2016

L’effervescence actuelle autour des phénomènes émotionnels enjoint les entreprises à proposer des produits suscitant des émotions plutôt que seulement orientés vers la satisfaction des besoins des consommateurs. Poursuivre l’objectif de développer des produits à forte composante émotionnelle pose la question des modalités de prise en compte des émotions générées par le produit au cours de son processus de conception. Dans cet article, les auteurs analysent cette question dans le contexte de l’automobile en tant que produit émotionnel et à fort degré de complexité.
The Role of Anthropological Literature in Contemporary Shamanic Practices
Authors: Hytönen-Ng Elina
Published: May 2016

Anthropology and anthropological literature have had an irreversible
effect on the practice of contemporary shamanism. In this small-scale
study, I look at the complex ways the literature has been recorded,
initiated interest, revived and verified the shamanic practices. Over
the years, anthropologists have also caused distortions in revived
practices as they have left some things unrecorded. On the basis of
written responses and interviews from shamanic practitioners and
active drumming-group members, I demonstrate that the argument
of neo-shamanism as the only form of shamanism still alive is not
completely true. Attention is drawn also to the claim about the cycle
of learning in contemporary shamanism. My argument is that the
main part of learning in the deeper levels of shamanic practices still
happens in face-to-face situations.
A systematic approach to practically efficient general two-party secure function evaluation protocols and their modular design
Authors: Kolesnikov Vladimir , Sadeghi Ahmad-Reza , Schneider Thomas
Published: May 2016

General two-party Secure Function Evaluation (SFE) allows mutually distrusting parties to correctly compute any function on their private input data, without revealing the inputs. Two-party SFE can benefit almost any client-server interaction where privacy is required, such as privacy-preserving credit checking, medical classification, or face recognition. Today, SFE is a subject of immense amount of research in a variety of directions and is not easy to navigate.

In this article, we systematize the most practically important works of the vast research knowledge on general SFE. We argue that in many cases the most efficient SFE protocols are obtained by combining several basic techniques, e.g., garbled circuits and (additively) homomorphic encryption.

As a valuable methodological contribution, we present a framework in which today's most efficient techniques for general SFE can be viewed as building blocks with well-defined interfaces that can be easily combined into a complete efficient solution. Further, our approach naturally allows automated protocol generation (compilation) and has been implemented partially in the TASTY framework.

In summary, we provide a comprehensive guide in state-of-the-art SFE, with the additional goal of extracting, systematizing and unifying the most relevant and promising general SFE techniques. Our target audience are graduate students wishing to enter the SFE field and advanced engineers seeking to develop SFE solutions. We hope our guide paints a high-level picture of the field, including most common approaches and their trade-offs and gives precise and numerous pointers to formal treatment of its specific aspects.
Aggregating vulnerability metrics in enterprise networks using attack graphs
Authors: Homer John , Zhang Su , Ou Xinming , Schmidt David , Du Yanhui , Rajagopalan S. Raj , Singhal Anoop
Published: May 2016

Quantifying security risk is an important and yet difficult task in enterprise network security management. While metrics exist for individual software vulnerabilities, there is currently no standard way of aggregating such metrics. We present a model that can be used to aggregate vulnerability metrics in an enterprise network, producing quantitative metrics that measure the likelihood breaches can occur within a given network configuration. A clear semantic model for this aggregation is an important first step toward a comprehensive network security metric model. We utilize existing work in attack graphs and apply probabilistic reasoning to produce an aggregation that has clear semantics and sound computation. We ensure that shared dependencies between attack paths have a proportional effect on the final calculation. We correctly reason over cycles, ensuring that privileges are evaluated without any self-referencing effect. We introduce additional modeling artifacts in our probabilistic graphical model to capture and account for hidden correlations among exploit steps. The paper shows that a clear semantic model for aggregation is critical in interpreting the results, calibrating the metric model, and explaining insights gained from empirical evaluation. Our approach has been rigorously evaluated using a number of network models, as well as data from production systems.
Towards a cryptographic treatment of publish/subscribe systems
Authors: Yuen Tsz Hon , Susilo Willy , Mu Yi
Published: May 2016

Publish/subscribe mechanism is a typical many-to-many messaging paradigm when multiple applications want to receive the same message or when a group of applications would like to notify each other. Nonetheless, there exist only a few works that address the security issues for content-based publish/subscribe systems formally. Although the security requirements have been partially addressed by Wang et al., there is no formal definition for all of these security requirements in the literature. As a result, most of the existing schemes do not have any security proof and it is difficult to justify whether those schemes are really secure in practice. Furthermore, there is no comprehensive scheme that satisfies the most essential security requirements at the same time. In this paper, we introduce the first security model for important security requirements of content-based publish/subscribe systems. We also give a new security requirement for publisher authenticity, which means that the publisher is authenticated to publish certain types of notification only, and cannot publish other types of notification. We then exhibit a new scheme which fulfills most of the security requirements. Furthermore, we also provide a comprehensive proof for our concrete construction according to the new model.
Automated detection of parameter tampering opportunities and vulnerabilities in web applications
Authors: Bisht Prithvi , Hinrichs Timothy , Skrupsky Nazari , Venkatakrishnan V.N.
Published: May 2016

Parameter tampering attacks are dangerous to a web application whose server fails to replicate the validation of user-supplied data that is performed by the client in web forms. Malicious users who circumvent the client can capitalize on the missing server validation. In this paper, we provide a formal description of parameter tampering vulnerabilities and a high level approach for their detection. We specialize this high level approach to develop complementary detection solutions in two interesting settings: blackbox (only analyze client-side code in web forms) and whitebox (also analyze server-side code that processes submitted web forms). This paper presents interesting challenges encountered in realizing the high level approach for each setting and novel technical contributions that address these challenges. We also contrast utility, difficulties and effectiveness issues in both settings and provide a quantitative comparison of results. Our experiments with real world and open source applications demonstrate that parameter tampering vulnerabilities are prolific (total 47 in 9 applications), and their exploitation can have serious consequences including unauthorized transactions, account hijacking and financial losses. We conclude this paper with a discussion on countermeasures for parameter tampering attacks and present a detailed survey of existing defenses and their suitability.
Policy analysis for administrative role based access control without separate administration
Authors: Yang Ping , Gofman Mikhail I. , Stoller Scott D. , Yang Zijiang
Published: May 2016

Role based access control (RBAC) is a widely used approach to access control with well-known advantages in managing authorization policies. This paper considers user-role reachability analysis of administrative role based access control (ARBAC), which defines administrative roles and specifies how members of each administrative role can change the RBAC policy. Most existing works on user-role reachability analysis assume the separate administration restriction in ARBAC policies. While this restriction greatly simplifies the user-role reachability analysis, it also limits the expressiveness and applicability of ARBAC. In this paper, we consider analysis of ARBAC without the separate administration restriction and present new techniques to reduce the number of ARBAC rules and users considered during analysis. We also present parallel algorithms that speed up the analysis on multi-core systems. The experimental results show that our techniques significantly reduce the analysis time, making it practical to analyze ARBAC without separate administration.
Relations between secrets: two formal analyses of the Yahalom protocol
Authors: Paulson Lawrence C.
Published: May 2016

The Yahalom protocol is one of those analyzed by Burrows et al. [5]. Based upon their analysis, they have proposed modifications to make the protocol easier to understand and to analyze. Both versions of Yahalom have now been analyzed using Isabelle/HOL. Modified Yahalom satisfies strong security goals, and the original version is adequate. The mathematical reasoning behind these machine proofs is presented informally. An Appendix gives extracts from a formal proof.

Yahalom presents special difficulties because the compromise of one session key compromises other secrets. The proofs show that the resulting losses are limited. They rely on a new proof technique, which involves reasoning about the relationship between keys and the secrets encrypted by them. This technique is applicable to other difficult protocols, such as Kerberos IV [2].

The new proofs do not rely on a belief logic. They use a fundamentally different formal model: the inductive method. They confirm the BAN analysis and the advantages of the proposed modifications. The new proof methods detect more flaws than BAN and analyze protocols in finer detail, while remaining broadly consistent with the BAN principles. In particular, the proofs confirm the explicitness principle of Abadi and Needham [1]. The proofs also suggest that any realistic model of security must admit that secrets can become compromised over time.
Distributed credential chain discovery in trust management
Authors: Li Ninghui , Winsborough William H. , Mitchell John C.
Published: May 2016

We introduce a simple Role-based Trust-management language [Formula: see text] and a set-theoretic semantics for it. We also introduce credential graphs as a searchable representation of credentials in [Formula: see text] and prove that reachability in credential graphs is sound and complete with respect to the semantics of [Formula: see text]. Based on credential graphs, we give goal-directed algorithms to do credential chain discovery in [Formula: see text], both when credential storage is centralized and when credential storage is distributed. A goal-directed algorithm begins with an access-control query and searches for credentials relevant to the query, while avoiding considering the potentially very large number of credentials that are unrelated to the access-control decision at hand. This approach provides better expected-case performance than bottom-up algorithms. We show how our algorithms can be applied to SDSI 2.0 (the ‘SDSI’ part of SPKI/SDSI 2.0).

Our goal-directed, distributed chain discovery algorithm finds and retrieves credentials as needed. We prove that the algorithm is correct by proving that the algorithm is sound and complete with respect to the credential graph composed of the credentials it retrieves, and that the algorithm retrieves all credentials that constitute a traversable chain. We further introduce a storage type system for [Formula: see text], which guarantees traversability of chains when credentials are well typed. This type system can also help improve search efficiency by guiding search in the right direction, making distributed chain discovery with large number of credentials feasible.
Coordinated Internet attacks: responding to attack complexity
Authors: Ourston Dirk , Matzner Sara , Stump William , Hopkins Bryan
Published: May 2016

This paper examines the issues involved with responding to complex Internet attacks. Such attacks characteristically occur in stages over extended periods of time and allow specific actions in a particular stage to be interchangeable. The stages can be extremely difficult to correlate because they are separated in time, and these effects can be deliberately obscured to achieve the goals of the attacker. We have chosen an approach to intrusion detection using Hidden Markov Models (HMMs) that explicitly addresses these issues. As part of our research we also developed a methodology for labeling examples that reduced the effort involved from that of labeling thousands of training examples to that of labeling less than two hundred feature values. When compared with two classic machine learning algorithms, decision trees and neural nets, the HMM algorithm provides an approximately five-% performance advantage over the decision tree algorithm, and at least a thirty % advantage over neural nets, at all training levels. The HMM performance advantage over decision trees is shown to increase as the complexity of the attack increases. The HMM performance advantage also increases as the number of training examples decreases. This last result indicates that the HMM algorithm may have additional benefit when examples of a particular attack type are rare.
A group key recovery mechanism based on logical key hierarchy
Authors: Cho Taenam , Lee Sang-Ho , Kim Won
Published: May 2016

Secret group communication can be achieved by encryption messages with a group key. Dynamic groups face the problem of changing the group key whenever members join or leave. One of the solutions to this problem is to send updated group keys to members via rekey messages in a secure manner. The recovery of lost group keys consequently becomes important because a member cannot decrypt the group data if she loses the rekey messages. Also, any rekey messages lost while a member is logged off cannot be recovered in real-time. Saving recent rekey messages and resending them by the key distribution center not only requires large storage space, but also can cause unnecessary transmission and decryption of keys. Furthermore, the keys in the unsaved rekey messages cannot be recovered. This paper analyzes the problem of rekey message loss and proposes an efficient scheme for recovering group keys based on a logical key hierarchy. The group key generation method used in the scheme makes it possible to recover group keys without transmission and decryption of useless keys.
Research on automated rollbackability of intrusion response
Authors: Zhang Jian , Gong Jian , Ding Yong
Published: May 2016

The rollbackable automated intrusion response mechanism, a method whereby an intrusion response can be treated by in the context of the detection/response life-cycle. The idea derives from the observation that most intrusion responses have negative effects. To decrease the cumulative response cost, response rollback could be carried out at some suitable time, for example when the attack has terminated or the attack ‘detection’ is proved to be a false positive. Additionally, technologies supporting automated response are proposed, such as the structure of a response policy and the way the automated response might be implemented. A proposed implementation structure of rollbackable automated intrusion response system (RAIRS) is also given. With the quantified response cost, the result of our experiments shows that response rollback is promising as a way to decrease the expected cumulative intrusion response cost.
Providing process origin information to aid in computer forensic investigations
Authors: Buchholz Florian P. , Shields Clay
Published: May 2016

The number of computer attacks has been growing dramatically as the Internet has grown. Attackers currently have little or no disincentive to conducting attacks because they are able to hide their location effectively by creating a chain of connections through a series of hosts. This method is effective because most current host audit systems do not maintain enough information to allow association of incoming and outgoing network connections. In this paper, we introduce an inexpensive method that allows both on-line and forensic matching of incoming and outgoing network traffic. Our method makes small modifications to the operating system that associate origin information with each process in the system process table, and enhances the audit information by logging the origin and destination of network sockets. We present implementation results, show that our method can effectively record origin information about a variety of attacks, and describe the limitations of our approach.
A survey of algebraic properties used in cryptographic protocols
Authors: Cortier Véronique , Delaune Stéphanie , Lafourcade Pascal
Published: May 2016

Cryptographic protocols are successfully analyzed using formal methods. However, formal approaches usually consider the encryption schemes as black boxes and assume that an adversary cannot learn anything from an encrypted message except if he has the key. Such an assumption is too strong in general since some attacks exploit in a clever way the interaction between protocol rules and properties of cryptographic operators. Moreover, the executability of some protocols relies explicitly on some algebraic properties of cryptographic primitives such as commutative encryption. We give a list of some relevant algebraic properties of cryptographic operators, and for each of them, we provide examples of protocols or attacks using these properties. We also give an overview of the existing methods in formal approaches for analyzing cryptographic protocols.
GKMPAN: An Efficient Group Rekeying Scheme for Secure Multicast in Ad-Hoc Networks
Authors: Zhu Sencun , Setia Sanjeev , Xu Shouhuai , Jajodia Sushil
Published: May 2016

We present GKMPAN, an efficient and scalable group rekeying protocol for secure multicast in ad hoc networks. Our protocol exploits the property of ad hoc networks that each member of a group is both a host and a router, and distributes the group key to member nodes via a secure hop-by-hop propagation scheme. A probabilistic scheme based on pre-deployed symmetric keys is used for implementing secure channels between members for group key distribution. GKMPAN also includes a novel distributed scheme for efficiently updating the pre-deployed keys. GKMPAN has three attractive properties. First, it is significantly more efficient than group rekeying schemes that were adapted from those proposed for wired networks. Second, GKMPAN has the property of partial statelessness; that is, a node can decode the current group key even if it has missed a certain number of previous group rekeying operations. This makes it very attractive for ad hoc networks where nodes may lose packets due to transmission link errors or temporary network partitions. Third, in GKMPAN the key server does not need any information about the topology of the ad hoc network or the geographic location of the members of the group. We study the security and performance of GKMPAN through detailed analysis and simulation; we have also implemented GKMPAN in a sensor network testbed.
A policy-based methodology for security evaluation: A Security Metric for Public Key Infrastructures
Authors: Casola Valentina , Mazzeo Antonino , Mazzocca Nicola , Vittorini Valeria
Published: May 2016

The security of complex infrastructures depends on many technical and organizational issues that need to be properly addressed by a security policy. For purpose of our discussion, we define a security policy as a document that states what is and what is not allowed in a system during normal operation; it consists of a set of rules that could be expressed in formal, semi-formal or very informal language. In many contexts, a system can be considered secure and trustworthy if the policy enforced by its security administrator is trustworthy too; from this standpoint it is possible to evaluate the system security by evaluating its policy.

In this paper we present a policy-based methodology to formalize and compare policies, and a Security Metric to evaluate the security level that a system is able to grant. All the steps of the methodology will be illustrated with an operative approach, by directly applying it to a real case study: the semi-automated Cross Certification among Public Key Infrastructures.
A static analysis for quantifying information flow in a simple imperative language
Authors: Clark David , Hunt Sebastian , Malacaria Pasquale
Published: May 2016

We propose an approach to quantify interference in a simple imperative language that includes a looping construct. In this paper we focus on a particular case of this definition of interference: leakage of information from private variables to public ones via a Trojan Horse attack. We quantify leakage in terms of Shannon’s information theory and we motivate our definition by proving a result relating this definition of leakage and the classical notion of programming language interference. The major contribution of the paper is a quantitative static analysis based on this definition for such a language. The analysis uses some non-trivial information theory results like Fano’s inequality and the [Formula: see text] inequality to provide reasonable bounds for conditional statements. While-loops are handled by integrating a qualitative flow-sensitive dependency analysis into the quantitative analysis.
e-Passports as a means towards a Globally Interoperable Public Key Infrastructure
Authors: Lekkas Dimitrios , Gritzalis Dimitris
Published: May 2016

Millions of citizens around the world have already acquired their new electronic passport. The e-passport is equipped with contactless communication capability, as well as with an Integrated Circuit Chip enabling cryptographic functionality. Countries are required to build a national Public Key Infrastructure to support digital signatures, as this is considered the basic mechanism to prove the authenticity and integrity of the Machine Readable Travel Documents. The first, large-scale, worldwide PKI is currently under construction, by means of bilateral trust relationships between Countries. In this paper, we propose a set of good practices, which are essential for the establishment of a global identification scheme based on e-passports, together with an analysis of the security and privacy issues that may arise. We argue that an e-passport may also be exploited in other applications as a globally interoperable PKI-enabled tamperproof device. The preconditions, the benefits and the drawbacks of using e-passports in everyday electronic activities are further analyzed and assessed.
Certificate revocation release policies
Authors: Hu Nan , Tayi Giri K. , Ma Chengyu , Li Yingjiu
Published: May 2016

Public key infrastructure provides a promising foundation for verifying the authenticity of communicating parties and transferring trust over the Internet. The key issue in public key infrastructure is how to process certificate revocations. Previous research in this area has concentrated on the tradeoffs that can be made among different revocation options. No rigorous efforts have been made to understand the probability distribution of certificate revocation requests based on real empirical data.

In this study, we first collect real data from VeriSign and suggest a functional form for the probability density function of certificate revocation requests. Exponential distribution function is chosen as it adequately approximates the real data. We then provide an economic model based on which a certificate authority can choose the optimal Certificate Revocation List (CRL) release interval considering the intrinsic properties among different types of certificate services. To conclude we draw some insights by comparing the performance of four different CRL strategies.
Edge-RMP: Minimizing administrative assignments for role-based access control
Authors: Vaidya Jaideep , Atluri Vijayalakshmi , Guo Qi , Lu Haibing
Published: May 2016

Because of its ease of administration, role-based access control (RBAC) has become the norm to enforcing security in most of today's organizations. For implementing RBAC, it is important to devise a complete and correct set of roles. This task, known as role engineering, has been identified as one of the costliest components in deploying RBAC. A key problem with respect to role engineering is that there is no formal metric for measuring the goodness/interestingness of the devised set of roles. Recently, Vaidya et al. [26], formally define the role mining problem (RMP) as the problem of discovering an optimal set of roles from existing user permissions, and analyze its theoretical bounds. Essentially, given a user-permission assignment (UPA), the basic RMP is to discover the user-role assignment relation (UA) and role-permission assignment relation (PA) such that the number of roles required is minimum. In this paper, we present another interesting and useful problem, called the edge-RMP, with a different minimality objective. The edge-RMP, requires the discovery of a complete and correct set of roles such that the discovered |UA|+|PA| is the minimum possible. Minimal |UA|+|PA| is a useful metric as it would minimize the administrative burden since less number of assignments need to be managed. Although the basic-RMP and the edge-RMP appear to be related problems, we demonstrate with concrete examples that they are, in fact, independent of each other. We prove that the edge-RMP is an NP-hard problem by reducing the known “vertex cover problem” to the decision version of the edge-RMP. Another important contribution of this paper is to provide a binary integer programming solution to this problem by showing that the edge-RMP can be formulated in that form. As a result, one can directly borrow existing implementation solutions for binary integer programming and guide further research in this direction. We also propose a heuristic solution for large scale problems, and experimentally validate our algorithm.
Constructions of certificate-based signature secure against key replacement attacks
Authors: Li Jiguo , Huang Xinyi , Mu Yi , Susilo Willy , Wu Qianhong
Published: May 2016

In Eurocrypt 2003, Gentry introduced the notion of certificate-based encryption. The merit of certificate-based encryption lies in the following features: (1) providing more efficient public-key infrastructure (PKI) that requires less infrastructure, (2) solving the certificate revocation problem, and (3) eliminating third-party queries in the traditional PKI. Additionally, it also offers the solution to the inherent key escrow problem in the identity-based cryptography. The contributions of this paper are threefold. Firstly, we introduce a new attack called the “Key Replacement Attack” into the certificate-based signature system and refine the security model of certificate-based signature. Secondly, we show that the certificate-based signature scheme presented by Kang, Park and Hahn in CT-RSA 2004 is insecure against key replacement attacks. Thirdly, we present two new certificate-based signature schemes secure against key replacement attacks. Our first scheme is existentially unforgeable against adaptive chosen message attacks under the computational Diffie–Hellman assumption in the random oracle model. Compared with the certificate-based signature scheme in CT-RSA 2004, our first scheme enjoys shorter signature length and less operation cost. Our second scheme is inspired by Waters signature and is the first construction of certificate-based signature secure against key replacement attacks in the standard model.
Instant certificate revocation and publication using WebDAV
Authors: Chadwick David W. , Antony Sean , Bjerk Rune
Published: May 2016

There are several problems associated with the current ways that certificates are published and revoked. This paper discusses these problems, and then proposes a solution based on the use of WebDAV, an enhancement to the HTTP protocol. The proposed solution provides instant certificate revocation, minimizes the processing costs of the certificate issuer and relying party, and eases the administrative burden of publishing certificates and certificate revocation lists (CRLs). We describe how WebDAV can be used for X.509 certificate revocation, and describe how we have implemented it in the PERMIS authorization infrastructure.
An efficient signcryption scheme with key privacy and its extension to ring signcryption
Authors: Li Chung Ki , Yang Guomin , Wong Duncan S. , Deng Xiaotie , Chow Sherman S.M.
Published: May 2016

In Information Processing Letters (2006), Tan pointed out that the anonymous signcryption scheme proposed by Yang, Wong and Deng (YWD) in ISC 2005 provides neither confidentiality nor anonymity. However, no discussion has been made on how a secure scheme can be made and there is no secure scheme available to date. In this paper, we propose a modification of YWD scheme which resolves the security issues of the original scheme without sacrificing its high efficiency and simple design. Indeed, we show that our scheme achieves confidentiality, existential unforgeability and anonymity with more precise reduction bounds. We also give a variation of our scheme and extend it to a ring signcryption scheme by using the technique due to Boneh, Gentry, Lynn and Shacham.
Static analysis for detecting taint-style vulnerabilities in web applications
Authors: Jovanovic Nenad , Kruegel Christopher , Kirda Engin
Published: May 2016

The number and the importance of web applications have increased rapidly over the last years. At the same time, the quantity and impact of security vulnerabilities in such applications have grown as well. Since manual code reviews are time-consuming, error-prone and costly, the need for automated solutions has become evident.

In this paper, we address the problem of vulnerable web applications by means of static source code analysis. More precisely, we use flow-sensitive, interprocedural and context-sensitive data flow analysis to discover vulnerable points in a program. In addition to the taint analysis at the core of our engine, we employ a precise alias analysis targeted at the unique reference semantics commonly found in scripting languages. Moreover, we enhance the quality and quantity of the generated vulnerability reports by employing an iterative two-phase algorithm for fast and precise resolution of file inclusions. The presented concepts are targeted at the general class of taint-style vulnerabilities and can be easily applied to the detection of vulnerability types such as SQL injection, cross-site scripting (XSS), and command injection.

We implemented the presented concepts in Pixy, a high-precision static analysis tool aimed at detecting cross-site scripting and SQL injection vulnerabilities in PHP programs. To demonstrate the effectiveness of our techniques, we analyzed a number of popular, open-source web applications and discovered hundreds of previously unknown vulnerabilities. Both the high analysis speed as well as the low number of generated false positives show that our techniques can be used for conducting effective security audits.
Guessing attacks and the computational soundness of static equivalence
Authors: Baudet Mathieu , Warinschi Bogdan , Abadi Martín
Published: May 2016

The indistinguishability of two pieces of data (or two lists of pieces of data) can be represented formally in terms of a relation called static equivalence. Static equivalence depends on an underlying equational theory. The choice of an inappropriate equational theory can lead to overly pessimistic or overly optimistic notions of indistinguishability, and in turn to security criteria that require protection against impossible attacks or – worse yet – that ignore feasible ones. In this paper, we define and justify an equational theory for standard, fundamental cryptographic operations. This equational theory yields a notion of static equivalence that implies computational indistinguishability. Static equivalence remains liberal enough for use in applications. In particular, we develop and analyze a principled formal account of guessing attacks in terms of static equivalence.
Model-checking trace-based information flow properties
Authors: D'Souza Deepak , Holla Raveendra , Raghavendra K.R. , Sprick Barbara
Published: May 2016

In this paper we consider the problem of verifying trace-based information flow properties for different classes of system models. We begin by proposing an automata-theoretic technique for model-checking trace-based information flow properties for finite-state systems. We do this by showing that Mantel's Basic Security Predicates (BSPs), which were shown to be the building blocks of most trace-based properties in the literature, can be verified in an automated way for finite-state system models. We also consider the problem for the class of pushdown system models, and show that it is undecidable to check such systems for any of the trace-based information flow properties. Finally we consider a simple trace-based property we call “weak non-inference” and show that it is undecidable even for finite-state systems.
Authentication protocols based on low-bandwidth unspoofable channels: A comparative survey
Authors: Nguyen L.H. , Roscoe A.W.
Published: May 2016

One of the main challenges in pervasive computing is how we can establish secure communication over an untrusted high-bandwidth network without any initial knowledge or a Public Key Infrastructure. An approach studied by a number of researchers is building security though human work creating a low-bandwidth empirical (or authentication) channel where the transmitted information is authentic and cannot be faked or modified. In this paper, we give an analytical survey of authentication protocols of this type. We start with non-interactive authentication schemes, and then move on to analyse a number of strategies used to build interactive pair-wise and group protocols that minimise the human work relative to the amount of security obtained as well as optimising the computation processing. In studying these protocols, we will discover that their security is underlined by the idea of commitment before knowledge, which is refined by two protocol design principles introduced in this survey.
A profile anonymization model for location-based services
Authors: Shin Heechang , Vaidya Jaideep , Atluri Vijayalakshmi
Published: May 2016

Location-based services (LBS) aim at delivering point of need information. Personalization and customization of such services, based on the profiles of mobile users, would significantly increase the value of such services. Since profiles may include sensitive information of mobile users and moreover can help identify a person, such customization is allowable only when the security and privacy policies dictated by them are respected. While LBS providers are presumed to be untrusted entities, the location services that capture and maintain mobile users' location to enable communication are considered trusted, and therefore can capture and manage the profile information. The question then is, how to enable the use of location based services while protecting privacy?

In this paper, we address the problem of privacy preservation via anonymization. Prior research in this area attempts to ensure k-anonymity by generalizing the location. However, a person may still be identified based on his/her profile if the profiles of all k people in the generalized region are not the same. We extend the notion of k-anonymity by proposing a profile based k-anonymization model that guarantees anonymity even when profiles of mobile users are revealed to untrusted entities. Specifically, our anonymization methods generalize both location and profiles to the extent specified by the user. We propose a novel unified index structure, called the PTPR-tree to enhance the performance during anonymization. PTPR-tree is an extension of the TPR-tree [in: SIGMOD'00: Proceedings of the 2000 ACM SIGMOD International Conference on Management of Data, New York, NY, USA, ACM, 2000, pp. 331–342] which organizes both the locations of mobile users as well as their profiles using a single index, and therefore can efficiently find candidate users for the proposed profile based anonymization models.
Fast automatic security protocol generation
Authors: Zhou Hongbin , Foley Simon N.
Published: May 2016

An automatic security protocol generator is described that uses logic-based heuristic rules to guide it in a backward search for suitable protocols from protocol goals. The approach taken is unlike existing automatic protocol generators which typically carry out a forward search for candidate protocols from the protocol assumptions. A prototype generator has been built that performs well in the automatic generation of authentication and key exchange protocols.
Efficient construction of machine-checked symbolic protocol security proofs
Authors: Meier Simon , Cremers Cas , Basin David
Published: May 2016

We embed an untyped security protocol model in the interactive theorem prover Isabelle/HOL and derive a theory for constructing proofs of secrecy and authentication properties. Our theory is based on two key ingredients. The first is an inference rule for enumerating the possible origins of messages known to the intruder. The second is a class of protocol-specific invariants that formalize type assertions about variables in protocol specifications. The resulting theory is well suited for interactively constructing human-readable, protocol security proofs. We additionally give an algorithm that automatically generates Isabelle/HOL proof scripts based on this theory. We provide case studies showing that both interactive and automatic proof construction are efficient. The resulting proofs provide strong correctness guarantees since all proofs, including those deriving our theory from the security protocol model, are machine-checked.
Formal specification and management of security policies with collective group obligations
Authors: Cuppens Frédéric , Cuppens-Boulahia Nora , Elrakaiby Yehia
Published: May 2016

Obligations are an essential element of security policies since they enable the specification of many security requirements such as availability, privacy, usage control and data protection. In everyday life, the fulfillment of obligations is often the responsibility of more than one subject, e.g., “All patients must be checked by one of the doctors”. Obligations may also be fulfilled in different ways, e.g., “Every customer should pay either in cash or by check”. Current security policy languages do not enable the specification of these intuitive and much needed requirements. In this paper, we show how policy languages can be extended to support the specification of these requirements which we call group obligations. To clarify the semantics of group obligations, we introduce state-based models for both group and individual obligations and show how group obligations can be managed according to change in the state of individual obligations. We formalize the semantics of the model and interactions between individual and group obligations by introducing a policy-enforcement language ℒE. ℒE enables the formal description of the application domain and the policy and provides operational semantics for policy management. Moreover, we discuss termination and determinism of policy enforcement in the proposed framework and show how different sanction/reaction policies may be activated when group obligations are violated.
Neural network Trojan
Authors: Geigel Arturo
Published: May 2016

This paper presents a proof of concept of a neural network Trojan. The neural network Trojan consists of a neural network that has been trained with a compromised dataset and modified code. The Trojan implementation is carried out by insertion of a malicious payload encoded into the weights alongside with the data of the intended application. The neural Trojan is specifically designed so that when a specific entry is fed into the trained neural network, it triggers the interpretation of the data as payload. The paper presents a background on which this attack is based and provides the assumptions that make the attack possible. Two embodiments of the attack are presented consisting of a basic backpropagation network and a Neural Network Trojan with Sequence Processing Connections (NNTSPC). The two alternatives are used depending on the underlying circumstances on which the compromise is launched. Experimental results are carried out with synthetic as well as a chosen existing binary payload. Practical issues of the attack are also discussed, as well as a discussion on detection techniques.
Diversity and equitability of insect pests and natural enemies in brinjal field treated with insecticide
Authors: Awal A , Rahman MM , Alam MZ , Khan MMH
Published: May 2016

Experiment was conducted during winter season to study the diversity and equitability of insect pest species and natural enemies in insecticide treated brinjal fields. Highest number of insect pests were recorded in` Tracer 45 SC, Bactoil (Bt), Nimbicidene 0.03 EC and lowest was in Necstar-50 EC and Proclaim-5 SG treated plots. The highest total abundance of insect pest was recorded in the plots treated with Bactoil and Tracer-45 SC and lowest total abundance was in Helicide (HNPV), Proclaim-5 SG and Booster-10 EC treated plots. The diversity index and equitability of insect pest species were highest in the plots treated with Nimbicidene 0.03 EC and Bactoil in visual search and sweep net methods while Bactoil and Booster 10 EC in pitfall trap method. However, lowest diversity index and equitability were obtained from the plots treated with Booster 10 EC, Proclaim-5 SG, Necstar-50 EC, Tracer-45 SC in visual search and sweep net methods but also in plots treated with Nimbicidene 0.03 EC in pitfall trap method. In case of natural enemies, the highest number of families were recorded in Tracer-45 SC, Nimbicidine 0.03 EC and Bactoil treated plots while lowest was in Helicide, Booster 10 EC, Proclaim-5 SG and Necstar-50 EC treated plots. The highest total abundance of natural enemy was recorded in the plot treated with Bactoil and Tracer-45 SC while lowest abundance was in the plot treated with Necstar-50 EC and Boster-10 EC. The diversity index and equitability of natural enemies were the highest in the plots treated with Proclaim-5 SG, Bactoil, Helicide and Necstar-50 EC in visual search, sweep net method and pitfall trap method while lowest was in Booster 10 EC, Tracer-45 SC treated plots in visual search method, Booster 10 EC and Nimbicidene 0.03 EC treated plots in sweep net method, Necstar-50 EC and Nimbicidene 0.03 EC treated plots in pitfall trap method. Bactoil and Tracer-45 SC were relatively safe for natural enemies and therefore would be fit well into integrated pest management (IPM) against BSFB of brinjal crop.Jahangirnagar University J. Biol. Sci. 4(1): 71-80, 2015 (June)
Development of a Method for Selection of Effective Singular Values in Bearing Fault Signal De-Noising
Authors: Gao Jie , Wu Lifeng , Wang Hongmin , Guan Yong
Published: May 2016

Singular value decomposition (SVD) is a widely used and powerful tool for signal extraction under noise. Noise attenuation relies on the selection of the effective singular value because these values are significant features of the useful signal. Traditional methods of selecting effective singular values (or selecting the useful components to rebuild the faulty signal) consist of seeking the maximum peak of the differential spectrum of singular values. However, owing to the small number of selected effective singular values, these methods lead to excessive de-noised effects. In order to get a more appropriate number of effective singular values, which preserves the components of the original signal as much as possible, this paper used a difference curvature spectrum of incremental singular entropy to determine the number of effective singular values. Then the position was found where the difference of two peaks in the spectrum declines in an infinitely large degree for the first time, and this position was regarded as the boundary of singular values between noise and a useful signal. The experimental results showed that the modified methods could accurately extract the non-stationary bearing faulty signal under real background noise.
Recent Advances in Understanding the Effects of Climate Change on Coral Reefs
Authors: Hoey Andrew , Howells Emily , Johansen Jacob , Hobbs Jean-Paul , Messmer Vanessa , McCowan Dominique , Wilson Shaun , Pratchett Morgan
Published: May 2016

Climate change is one of the greatest threats to the persistence of coral reefs. Sustained and ongoing increases in ocean temperatures and acidification are altering the structure and function of reefs globally. Here, we summarise recent advances in our understanding of the effects of climate change on scleractinian corals and reef fish. Although there is considerable among-species variability in responses to increasing temperature and seawater chemistry, changing temperature regimes are likely to have the greatest influence on the structure of coral and fish assemblages, at least over short–medium timeframes. Recent evidence of increases in coral bleaching thresholds, local genetic adaptation and inheritance of heat tolerance suggest that coral populations may have some capacity to respond to warming, although the extent to which these changes can keep pace with changing environmental conditions is unknown. For coral reef fishes, current evidence indicates increasing seawater temperature will be a major determinant of future assemblages, through both habitat degradation and direct effects on physiology and behaviour. The effects of climate change are, however, being compounded by a range of anthropogenic disturbances, which may undermine the capacity of coral reef organisms to acclimate and/or adapt to specific changes in environmental conditions.