Cryptanalysis and Improvement of Several Convertible Ring Signature Schemes
Wang Hua-qun①②; Guo Xian-jiu①; Yu Hong①; Peng Yu-xu②
①School of Information Engineering, Dalian Fisheries University, Dalian 116023, China;②College of Computer and Communication Engineering, Changsha University of Science & Technology, Changsha, 410076, China
Abstract: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 security requirements for convertible ring signature.