Certificate-Based Sequential Aggregate Signature

In this paper, we propose a new notion called Certificate-Based Sequential Aggregate Signature. Certificate-based cryptography proposed by Gentry [8] combines the merit of traditional public key cryptography and identity based cryptography, without use of the costly certificate chain verification process and the removal of key escrow security concern. Under this paradigm, we propose a first sequential aggregate signature. An aggregate signature scheme produces a short string that convinces any verifier that there are n messages signed by n parties, all of which may be distinct. The length of the string is a constant which is independent of n. Its compactness makes it particularly suitable to be employed in those environments where communication bandwidth is very limited, such as wireless network scenarios (e.g. MANETS, cellular networks, sensor networks, satellite communication). We provide a concrete construction of this new notion and prove its security in the random oracle model.