Cryptanalysis and Improvement of Two Ring Signature Schemes
Wang Hua-qun①②; Zhang Li-jun①; Zhao Jun-xi③
①Department of Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, China; ②Information Engineering Institute, Dalian Fisheries University, Dalian 116023, China;③Department of Applied Mathematics and Physics, Nanjing University of Posts and Telecommunications, Nanjing 210003, China
Abstract：The security of the two ring signature schemes proposed by Xu(2004) and Zhang(2004) is analyzed, and it’s found that both the ring signature schemes are susceptible to group-changing attack. In addition, Zhang’s scheme can easily be attacked by multiple-known-signature existential forgery. To guard against the two attacks, the two ring signature schemes are improved, which can make the improved schemes is still secure even in the strongest security model (proposed by Joseph in 2004).
2007, Vol. 29 
