‎In this paper‎, ‎we propose some Diffie-Hellman type key exchange protocols using isogenies of elliptic curves‎. ‎The first method which uses the endomorphism ring of an ordinary elliptic curve $ E $‎, ‎is a straightforward generalization of elliptic curve Diffie-Hellman key exchange‎. ‎The method uses commutativity of the endomorphism ring $ End(E) $‎. ‎Then using dual isogenies‎, ‎we propose...

Three-party authenticated key exchange protocol is an important cryptographic technique in the secure communication areas, by which any two clients can verify the ability to use a server to establish communication. Recently, researchers have begun proposing new key exchange protocols that would not require the use of server public keys, but a human-memorable password. In this paper, we propose ...

In 2005, Abdalla and Pointcheval suggested a new variation of the computational DH assumption called chosen based computational Diffie Hellman (CCDH) and presented SPAKE-1 and SPAKE-2 simple password based authenticated key exchange protocols. Since then several three party password authenticated key agreement protocols have been proposed based on CCDH assumption but most of them broken. In thi...

We propose the first tight security proof for ordinary two-message signed Diffie-Hellman key exchange protocol in random oracle model. Our is based on strong computational assumption and multi-user of a digital signature scheme. With our proof, DH can be deployed with optimal parameters, independent number users or sessions, without need to compensate any loss. abstract approach new notion call...

The authentication key exchange protocol enables communication participants to authenticate each other and agree on the session key over an insecure public network. Recently, a three-party authentication key exchange protocol based on Elliptic curve cryptograph is proposed. In this paper, we improve the three-party encrypted key exchange protocol by bilinear maps. The proposed threeparty authen...

The Diffie-Hellman key-exchange protocol may naturally be extended to k > 2 parties. This gives rise to the generalized Diffie-Hellman assumption (GDH-Assumption). Naor and Reingold have recently shown an efficient construction of pseudo-random functions and proved its security based on the GDH-Assumption. In this note, we prove that breaking this assumption modulo a so called Blum-integer woul...

Asymmetric algorithm like Diffie-Hellman can be used to encrypt the SMS message in M-commerce or mobile banking system. Password key exchange protocol based on Diffie-Hellman key exchange algorithm allows users to exchange a secret key that can be used in message encryption. The security of this protocol can be increased by using the MAC (message authentication code) or hash function with the e...

This paper suggests a model and a definition for forward-secure authenticated key exchange (AKE) protocols, which can be satisfied without depending on the Diffie-Hellman assumption. The basic idea is to use key-evolving schemes (KES), where the long-term keys of the system get updated regularly and irreversibly. Protocols conforming to our model can be highly efficient, since they do not requi...