An efficient certificateless aggregate signature with constant pairing computations

An aggregate signature scheme enables an algorithm to aggregate n signatures of n distinct messages from n users into a single short signature. This primitive is useful in resource-constrained environment since they allow bandwidth and computational savings. Recently, in order to eliminate the use of certificates in certified public key cryptography and the key-escrow problem in identity-based cryptography, the notion of certificateless public key cryptography was introduced. In this paper, we present an efficient certificateless aggregate signature scheme with constant pairing computations. The security of the proposed scheme can be proved to be equivalent to the standard computational Diffie–Hellman problem in the random oracle with a tight reduction. Furthermore, our scheme does not require synchronization for aggregating randomness, which makes it more suitable for ad hoc networks.