National Institute of Standards and Technology における超伝導研究及び生活

A secure dynamic ID based remote user authentication scheme for multi-server environment

Improvement of the secure dynamic ID based remote user authentication scheme for multi-server environment

Concurrent executions of a zero-knowledge protocol by a single prover (with one or more verifiers) may leak information and may not be zero-knowledge in toto. In this article, we study the problem of maintaining zero-knowledge.We introduce the notion of an (α, β) timing constraint: for any two processors P1 and P2, if P1 measures α elapsed time on its local clock and P2 measures β elapsed time on its local clock, and P2 starts afterP1 does, then P2 will finish after P1 does. We show that if the adversary is constrained by an (α, β) assumption then there exist four-round almost concurrent zero-knowledge interactive proofs and perfect concurrent zero-knowledge arguments for every language in NP. We also address the more specific problem of Deniable Authentication, for which we propose several particularly efficient solutions. Deniable Authentication is of independent interest, even in the sequential case; our concurrent solutions yield sequential solutions without recourse to timing, that is, in the standard model.

Concurrent Zero-Knowledge.

An efficient and security dynamic identity based authentication protocol for multi-server architecture using smart cards

Recently, a new authentication scheme with anonymity for wireless communications has been proposed, and then some security problems have been demonstrated. In this paper, we will discuss a few problems found in the enhanced scheme and then propose how to overcome them, regarding the properties of anonymity and backward secrecy.

A Secure Authentication Scheme with Anonymity for Wireless Communications

A smart card-based remote scheme for password authentication in multi-server Internet services

A novel deniable authentication protocol using generalized ElGamal signature scheme

An enhanced user authentication scheme for multi-server Internet services

Remote user authentication is used to validate the legitimacy of a remote log-in user. Due to the rapid growth of computer community, many network architectures are becoming multi-server based. Recently, there have been many remote password authentication schemes proposed for securing multi-server environments. These schemes used either a nonce or a timestamp technique to prevent the replay attack. However, using the nonce technique to withstand the replay attack is potentially susceptible to the man-in-the-middle attack. Alternatively, when employing the timestamp method to secure remote password authentication, it will encounter the difficulty of implementing time synchronization. In order to solve both the above two issues, this paper proposes a self-verified timestamp technique to not only securely achieve password authenticated key agreement but also avoid the difficulty of implementing time synchronization in multi-server environments. On the other hand, the function of service period management can allow servers to update the list of illegal users easily and periodically. Therefore, we also further develop the scheme of service period management in this paper.

Chia-Chun Wu

Papers

A Secure Authentication Scheme with Anonymity for Wireless Communications

A smart card-based remote scheme for password authentication in multi-server Internet services

A novel deniable authentication protocol using generalized ElGamal signature scheme

An enhanced user authentication scheme for multi-server Internet services

A Secure Smart-Card-based Password Authenticated Key Agreement Scheme in Multi-server Environments