We propose an authentication scheme in which users can be authenticated anonymously so long as times that they are authenticated is within an allowable number. The proposed scheme has two features that allow 1) no one, not even an authority, identify users who have been authenticated within the allowable number, and that allow 2) anyone to trace, without help from the authority, dishonest users...

In this paper, we show that the Nalla-Reddy’s one round IDbased tripartite authenticated key agreement protocols are still insecure against the man-in-the-middle attacks. We also break the Nalla’s IDbased tripartite authenticated key agreement protocol with signatures.

We consider communication sessions in which a pair of parties begin by running an au-thenticated key-exchange protocol to obtain a shared session key, and then secure successivedata transmissions between them via an authenticated encryption scheme based on the sessionkey. We show that such a communication session meets the notion of a secure channel protocolproposed by Canetti a...

Vaudenay recently proposed a message authentication protocol which is interactive and based on short authenticated strings (SAS). We study here SASbased non-interactive message authentication protocols (NIMAP). We start by the analysis of two popular non-interactive message authentication protocols. The first one is based on a collision-resistant hash function and was presented by Balfanz et al...

Authenticated key agreements enable users to determine session keys, and to securely communicate with others over an insecure channel via the session keys. This study investigates the lower bounds on communications for three-party authenticated key agreements and considers whether or not the sub-keys for generating a session key can be revealed in the channel. Since two clients do not share any...

The current existing Authenticated Routing for Ad Hoc Networks (ARAN) secure routing protocol is capable of defending itself against most malicious nodes and their different attacks. However, ARAN is not capable of defending itself against any authenticated selfish node participating in the network. Therefore, the objective of my thesis is to make the Authenticated Routing for Ad Hoc Networks s...

Cryptographic primitives are required to protect an IT (Information Technology) system. They are used to provide CIA (Confidentiality, Integrity, and Availability) and other security attributes to the system. So far, NIST (National Institute of Standard and Technology) has successfully standardized AES (Advanced Encryption Standard) for confidentiality and SHA (Secure Hash Algorithm) for integr...