关键词: 聚合签名, 无证书密码体制, 双线性对, Diffie-Hellman困难问题

Abstract: Through analysis of a certificateless aggregate signature scheme proposed by Hou et al, it is revealed that the scheme is not secure and it cannot resist the type two adversary attack. Based on this scheme, an improved certificateless aggregate signature scheme is proposed in this paper. Under the computational Diffie-Hellman problem, it is proved that the new scheme is secure against existential forgery attack in the random oracle model. The result indicates that the new scheme only needs three pairing computations and n scalar multiplication computations in verification phase. The new scheme is more efficient and secure than existed schemes.

Key words: aggregate signature, certificateless cryptography, bilinear pairing, Diffie-Hellman assumption