Covert channels enable stealthy communications over innocent appearing carriers. They are increasingly applied in the network context. However, little work is available that exploits cryptographic primitives networking context to establish such covert communications. We present a channel between two devices where one device authenticates itself with Lamport’s one-time passwords based on hash fu...

Remote EAP-SIM authentication has an overwhelming impact on the authentication delay. RADIUS protocol can be used for local authentication which reduces authentication latency. However, in case of EAP-SIM authentication, where triplets are to be retrieved from a remote authentication gateway (AuC), this does not help much. An Improved EAP-SIM authentication method was proposed in [2]. In this p...

At present, the proposed authentication schemes can be classified into three categories. The first category is the watermarking authentication schemes in which the watermark is independent of the multimedia content. The second category is the signature-based authentication schemes in which the signature is generated by the multimedia content and is not embedded into the multimedia content. The ...

This thesis is divided into two distinct parts. The first part of the thesis explores various deniable signature schemes and their applications. Such schemes do not bind a unique public key to a message, but rather specify a set of entities that could have created the signature, so each entity involved in the signature can deny having generated it. The main deniable signature schemes we examine...

This paper presents an evolution of authentication mechanisms from textual passwords to graphical authentication mechanisms. For security concerns password must be protected from the unauthorized users. Authentication and authorization is necessary for essential data, this requires authentication mechanisms. An important goal for authentication is user has easy to memorize their passwords and r...