Cryptanalysis and Improvement of Several Convertible Ring Signature Schemes
几种可转换环签名方案的安全性分析和改进

The security of the three convertible ring signature schemes proposed by Zhang-Liu-He(2006),Gan-Chen(2004) and Wang-Zhang-Ma(2007) is analyzed,and it is found that these convertible ring signature schemes are susceptible to convertibility attack or non-repudiation attack,i.e.,any member in the ring can claim that he is the actual signer or pretend others' identity to sign message.To guard against the attack,these convertible ring signature schemes are improved,which can make the improved schemes satisfy the...