Authentication from matrix conjugation

We propose an authentication scheme where forgery (a.k.a. impersonation) seems infeasible without finding the prover's long-term private key. The latter would follow from solving the conjugacy search problem in the platform (noncommutative) semigroup, i.e., to recovering X from X^{-1}AX and A. The platform semigroup that we suggest here is the semigroup of nxn matrices over truncated multivariable polynomials over a ring.Comment: 6 page

Cryptography with right-angled Artin groups

In this paper we propose right-angled Artin groups as a platform for secret sharingschemes based on the efficiency (linear time) of the word problem. Inspired by previous work of Grigoriev-Shpilrain in the context of graphs, we de ne two new problems: SubgroupIsomorphism Problem and Group Homomorphism Problem. Based on them, we also proposetwo new authentication schemes. For right-angled Artin groups, the Group Homomorphismand Graph Homomorphism problems are equivalent, and the later is known to be NP-complete.In the case of the Subgroup Isomorphism problem, we bring some results due to Bridson whoshows there are right-angled Artin groups in which this problem is unsolvable.Professional Staff Congress-City University of New YorkCity Tech FoundationOffice of Naval ResearchEuropean Research CouncilNational Science FoundationMinisterio de Ciencia e Innovació

Cryptography with right-angled Artin groups

In this paper we propose right-angled Artin groups as a platform for secret sharingschemes based on the efficiency (linear time) of the word problem. Inspired by previous work of Grigoriev-Shpilrain in the context of graphs, we de ne two new problems: SubgroupIsomorphism Problem and Group Homomorphism Problem. Based on them, we also proposetwo new authentication schemes. For right-angled Artin groups, the Group Homomorphismand Graph Homomorphism problems are equivalent, and the later is known to be NP-complete.In the case of the Subgroup Isomorphism problem, we bring some results due to Bridson whoshows there are right-angled Artin groups in which this problem is unsolvable.Professional Staff Congress-City University of New YorkCity Tech FoundationOffice of Naval ResearchEuropean Research CouncilNational Science FoundationMinisterio de Ciencia e Innovació

A Survey on Wireless Sensor Network Security

Wireless sensor networks (WSNs) have recently attracted a lot of interest in the research community due their wide range of applications. Due to distributed nature of these networks and their deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. This problem is more critical if the network is deployed for some mission-critical applications such as in a tactical battlefield. Random failure of nodes is also very likely in real-life deployment scenarios. Due to resource constraints in the sensor nodes, traditional security mechanisms with large overhead of computation and communication are infeasible in WSNs. Security in sensor networks is, therefore, a particularly challenging task. This paper discusses the current state of the art in security mechanisms for WSNs. Various types of attacks are discussed and their countermeasures presented. A brief discussion on the future direction of research in WSN security is also included.Comment: 24 pages, 4 figures, 2 table

Solutions and Tools for Secure Communication in Wireless Sensor Networks

Secure communication is considered a vital requirement in Wireless Sensor Network (WSN) applications. Such a requirement embraces different aspects, including confidentiality, integrity and authenticity of exchanged information, proper management of security material, and effective prevention and reaction against security threats and attacks. However, WSNs are mainly composed of resource-constrained devices. That is, network nodes feature reduced capabilities, especially in terms of memory storage, computing power, transmission rate, and energy availability. As a consequence, assuring secure communication in WSNs results to be more difficult than in other kinds of network. In fact, trading effectiveness of adopted solutions with their efficiency becomes far more important. In addition, specific device classes or technologies may require to design ad hoc security solutions. Also, it is necessary to efficiently manage security material, and dynamically cope with changes of security requirements. Finally, security threats and countermeasures have to be carefully considered since from the network design phase. This Ph.D. dissertion considers secure communication in WSNs, and provides the following contributions. First, we provide a performance evaluation of IEEE 802.15.4 security services. Then, we focus on the ZigBee technology and its security services, and propose possible solutions to some deficiencies and inefficiencies. Second, we present HISS, a highly scalable and efficient key management scheme, able to contrast collusion attacks while displaying a graceful degradation of performance. Third, we present STaR, a software component for WSNs that secures multiple traffic flows at the same time. It is transparent to the application, and provides runtime reconfigurability, thus coping with dynamic changes of security requirements. Finally, we describe ASF, our attack simulation framework for WSNs. Such a tool helps network designers to quantitatively evaluate effects of security attacks, produce an attack ranking based on their severity, and thus select the most appropriate countermeasures