ElGamal-like digital signature and multisignature schemes using self-certified public keys

In this paper, we first present a digital signature scheme using self-certified public key. Subsequently, we present a digital multisignature scheme extended from the proposed digital signature. Both the proposed schemes have the advantage that the authentication of the public key can be accomplished with the verification of the signature or multisignature. The security of both the proposed schemes is based on the one-way hash function, the factorization and the discrete logarithm assumptions. Moreover, the proposed multisignature scheme preserves the main merits inherent in most of the previously developed schemes. We also demonstrate that the proposed multisignature scheme can withstand the active attack that some malicious impostors try to universally forge an individual signature or a multisignature for a given message that is rejected to be signed by the other co-signers. (C) 2000 Elsevier Science Inc. All rights reserved.