摘要： Aggregate signature schemes are introduced to compress signatures under different keys into one. Sequential aggregate signature is a special kind of aggregate signature, in this kind of scheme, the aggregate signature is computed incrementally by the signers. There has been many sequential aggregate signature constructed. A main class of sequential aggregate signatures are based on trapdoor permutation. A construction of sequential aggregate signature is given which can be seen as an improvement of the scheme proposed by Brogle et. al. The scheme proposed releases one of the two random oracles used in Brogle et. al's construction, which makes the scheme more efficient.