Logarithmic size ring signatures without random oracles

Abstract

Ring signatures enable a user to anonymously sign a message on behalf of group of users. In this study, the authors propose the first ring signature scheme whose size is O (log 2 N ), where N is the number of users in the ring. They achieve this result by improving Chandran et al .’s ring signature scheme presented at the International Colloquium on Automata, Languages and Programming 2007. Their scheme uses a common reference string and non‐interactive zero‐knowledge proofs. The security of their scheme is proven without requiring random oracles.