An Efficient Identity-based Ring Signcryption Scheme

摘要

This paper presents an identity based ring signcryption scheme without random oracle by using bilinear pairings. The size of the ciphertext is a constant and independent of the size of the ring. By introducing the selective identity and selective chosen message attack model, we prove unforgeability of the scheme under the hardness of DHI problem and prove its indistinguishability against selective identity and chosen ciphertext attack under the hardness of DBDHE problem. This scheme is more efficient compared with other ring signcryption schemes.