Forward Secure Non-Interactive Key Exchange from Indistinguishability Obfuscation

Abstract

Recently, an efficient obfuscator of indistinguishability obfuscation was constructed by Grag et al, and it is considered as a powerful cryptographic primitive. In this paper, we propose forward secure non-interactive key exchange from indistinguishability obfuscation. A non-interactive key exchange provides an efficiency of overall system, because there are no interactions between users for key exchange. Forward security is important security requirement, because it mitigates damage when user's private key is revealed. In 2014, Pointcheval and Sanders proposed the first forward secure non- interactive key exchange scheme from multilinear map. In their scheme, there is a lifetime of a system and the lifetime is divided into time period. A user updates its private key according to time period, so the scheme has limits in the number of updates of private key. To make it free from limits of the number of updates, we design forward secure non-interactive key exchange scheme from indistinguishability obfuscation. In our scheme, there is no limits in the number of updates of private key.