关键词: 部分盲签名, 私钥生成中心, gap Diffie-Hellman群, 双线性对, 不可伪造性, 可追踪性

Abstract: The partially blind signature scheme without trusted Private Key Generator (PKG) proposed by Feng Tao et al. was analyzed, and it was found that this scheme did not satisfy unforgeability. A dishonest PKG could forge a valid partially blind signature. By using gap Diffie-Hellman group and bilinear pairings, a new partially blind signature scheme without trusted PKG was proposed. The analysis shows that the proposed scheme can overcome the defect of the original scheme and it possesses unforgeability, correctness, partially and tracility. Compared with the original scheme, the proposed scheme performs more efficiently in computation because it reduces two pairing operations.

Key words: partially blind signature, Private Key Generator (PKG), gap Diffie-Hellman group, bilinear pairings, unforgeability, tracility