A NEW CONSTRUCTION OF IDENTITY-BASED SIGNCRYPTION WITHOUT RANDOM ORACLES

Abstract

Identity-based signcryption is a primitive that combines the functions of identity-based encryption and identity-based signature. In this paper, we first attack two of the existing identity-based signcryption schemes which are claimed to be provably secure without random oracles. Then we construct a new identity-based signcryption scheme and proves its security without random oracles.