关键词: 双线性对, 无证书签名, 公钥替换攻击, 计算性Diffie-Hellman问题, 逆运算Diffie-Hellman问题

Abstract: Nowadays, many centificateless signature schemes depend on the honesty of Key Generation Center (KGC) excessively, so they also lose security guarantees when the KGC is dishonest. By analyzing the security of the certificateless signature scheme proposed by Liang Hongmei et. al. in security analysis and improvement of efficient certificateless signature scheme publicated by Journal fo Computer Applications, 2010,30(3):685-687, where the authors pointed out that the scheme could not resist public key replacement attack under negative dishonest KGC and positive dishonest KGCs attacks. Aiming at these problems, the scheme was improved by the means that KGC generated the users public key and made it public. The analysis of security shows that the improved scheme is able to resist public key replacement attack under negative dishonest KGC, thus successfully distinguishing the positive dishonesty of KGC,and resisting existential forgery on adaptively chosen message attack under the random oracle model.

Key words: bilinear paring, certificateless signature, public key replacement attack, Computational Diffie-Hellman Problem (CDHP), Inverse-Computational Diffie-Hellman Problem (Inv-CDHP)