Signature Scheme with Arbitrary Length Message Recovery in CPK

Digital signature with message recovery is regard as a useful method to shorten signature. This paper presents an identity-based signature scheme with message recovery, which applies to the Combined Public Key System. The scheme is provable secure against existential forgery against adaptively chosen message and ID attacks in the random oracle model under the elliptic curve discrete logarithm assumption. The proposed scheme can recover message with arbitrary length and shorten the total length of the original message and the appended signature compared with others. The proposed scheme is especially suitable for the computation and communication source constrained, such as Ad-hoc network.