Abstract:

A short signcryption scheme with ciphertext anonymity and forward security is proposed, which can protect the privacy of the sender and the receiver identities. The security models, including semantic security, unforgeability, ciphertext anonymity, forward security and verifiability, are analyzed in the random oracle models. In computational cost, the proposed scheme only need two scalar multiple operators in signcryption phase and two bilinear pairings and one scalar multiple operators in unsigncryption phase. Compared with the short signcryption schemes up to date, the computational costs of the new scheme are lower than those of signcryption schemes available where it has stronger security components, which can be used in the security requirement such as bandwidth constraint and identity hiding.

Key words: short signcryption, ciphertext anonymity, forward security, bilinear pairings