Research On Provably Security Of Authenticated Key Exchange Protocols

Provably security was first proposed by Goldwasser and Micali et al’s in1984. They put forward the definition of semantic security, and brought this idea into formal analysis. Since then, many scholars took use of provably security theory to present the security of some given protocols. There is a rapidly growing appreciation of provably security in cryptology. Proof of security currently can be divided into two categories, one is in the random oracle model (ROM), and the other is in the standard model.Research of this paper is mainly about the provably secutiy of authenticate key exchange (AKE) protocols. People’s attention has been drawn by two merits of AKE protocols. One is to agree on a common session key; the other is to realize mutual authentication.The main contents of this paper are as follows:(1) Present a verifier-based password authenticated key exchange protocol for N party, VB-nPAKE, against server leak attacks and password guessing attack. Prove the success probability of adversary attacking VB-nPAKE is negligible in random oracle model by using game sequence and hybrid technique.(2) Propose two flexibility and adaptability identity-based AKE protocols, IBK-1and IBK-2. Think of the unreality of security in ROM, this paper research on the security proof of AKE protocols in standard model with reduction proof method.(3) Propose a generic framework for AKE protocols based on the computational-hidden commitment algorithm, smooth projective hashing and DDH assumption. Extend the framework to three-party mode including single server mode and cross-realm mode, and the security of frameworks are proved in standard model.