An Efficient Verifiable Implicit Asking Protocol for Diffie-Hellman Key Exchange

An efficient verifiable implicit asking (VIA) protocol for Diffie-Hellman key exchange and its improvement are proposed. The proposed protocol utilizes an existing efficient implicit asking protocol for secret computation of RSA cryptosystem. The structure of the proposed protocol makes it resistant to both active and passive attacks. An known passive attack that decreases efficiency is not applied to the proposed protocol and the efficiency of the existing protocol is not sacrificed. When the required security is determined as the complexity in exhaustive searching of 2¹¹², the proposed protocol can execute Diffie-Hellman key exchange with 108 modular multiplications.