Paper 2003/023

New identity based signcryption schemes from pairings

Benoît Libert and Jean-Jacques Quisquater

Abstract

We present a new identity based scheme based on pairings over elliptic curves. It combines the functionalities of signature and encryption and is provably secure in the random oracle model. We compare it with Malone-Lee's one from security and efficiency points of view. We give a formal proof of semantical security under the Decisional Bilinear Diffie-Hellman assumption for this new scheme and we show how to devise other provably secure schemes that produce even shorter ciphertexts.

Note: The security proofs contained in this paper have been somewhat corrected