关键词: 环签名, 可验证环签名, 双线性对, 不可否认性, 匿名性

Abstract: By analyzing the certificateless verifiable ring signature scheme (LUO DAWEN, HE MINGXING, LI XIAO. Certificateless verifiable ring signature scheme. Computer Engineering,2009, 35(15): 135-137) and the verifiable proxy ring signature scheme (LUO DAWEN, HE MINGXING, LI XIAO.A verifiable proxy ring signature scheme.Journal of Southwest University for Nationalities:Natural Science Edition, 2009, 35(3):608-611), it was found that these convertible ring signature schemes were susceptible to non-repudiation attack, i.e., any member in the ring can impersonate others identity to sign the message and the verifier believed the signature was signed by the latter. To address the above problems, improved schemes were proposed by using the private key of the signer to have a secret value. The security analysis proves that the improved schemes overcome the security defect of the original scheme and satisfy all security requirements of verifiable ring signature.

Key words: ring signature, verifiable ring signature, bilinear pairings, non-repudiation, anonymity