We examine multi-party key agreement protocols that provide (i) key authentication, (ii) key confirmation and (iii) forward secrecy. Several minor (repairable) attacks are presented against previous two-party key agreement schemes and a model for key agreement is presented that provably provides the properties listed above. A generalization of the Burmester-Desmedt model (Eurocrypt '94) for multi-party key agreement is given, allowing a transformation of any two-party key agreement scheme into a multi-party scheme. Multi-party schemes (based on the general model and two specific 2-party schemes) are presented that reduce the number of rounds required for key computation compared to the specific Burmester-Desmedt scheme. It is also shown how the specific Burmester-Desmedt scheme fails to provide key authentication. 1991 AMS Classification: 94A60 CR Categories: D.4.6 Key Words: multi-party, key agreement, key authentication, key confirmation, forward secrecy. Carleton University, Sc...

Multipath routing minimizes the consequences of security attacks deriving from collaborating malicious nodes in MANET, by maximizing the number of nodes that an adversary must compromise in order to take control of the communication. In this paper, we identify several attacks that render multipath routing protocols more vulnerable than it is expected, to collaborating malicious nodes. We propose a novel on-demand multipath routing protocol, the Secure Multipath Routing protocol (SecMR) and we analyze its security properties. The SecMR protocol can be easily integrated in a wide range of on-demand routing protocols, such as DSR and AODV. 1

Most of today’s Internet routing protocols forward packets of a connection over a single path. This means that, even if redundant resources are available, a single failure (accidental or due to malicious activities) along a route will interrupt connections that use that route. Given the reactive approach to failure recovery that most current routing protocols employ, these communication disruptions may last for long enough time to be noticeable by higher protocol layers. Also, given that the path over which a connection’s packets travels is fairly predictable and easy to determine, connections are vulnerable to packet interception and eavesdropping attacks. In this paper, we introduce the Game-Theoretic Stochastic Routing (GTSR) framework, a proactive alternative to today’s reactive approaches to route repair. GTSR minimizes the impact of link and router failure by: (1) computing multiple paths between source and destination and (2) selecting among these paths randomly to forward packets. Moreover, besides improving fault-tolerance, the fact that GTSR makes packets take random paths from source to destination also improves security. For example, it makes connection eavesdropping attacks maximally difficult as the attacker would have to listen on all possible routes. The approaches developed are suitable for network layer routing as well as for application layer

Stalking is a pattern of behavior over time in which a stalker seeks to gain access to, or control over, a victim. Such actions range from the benign to the malicious and may cause emotional distress or harm to the victim. With the widespread adoption of new technologies, new forums of Internetmediated discourse now exist which offer stalkers unprecedented access to find and exert influence over victims. Cyberstalking, the convergence of stalking and cyberspace, has created new challenges for the prevention, detection, and prosecution of this new phenomenon as the traditional methods of detection by witnesses and enforcement by restraining orders often are inadequate. In this paper we suggest a cryptographic approach for the tracking of cyberstalkers. We first define the threat model in terms of a profile of the cyberstalker as well as legal and law enforcement constraints. We then describe a monitoring system that addresses the basic security requirements of our threat model by capturing and verifying circumstantial evidence for use in cyberstalking investigations.

1.4 Simple XOR