Analysis and Improvement of a Perfect Concurrent Signature Protocol
Qiuliang Xu · Beijing Youdian Xueyuan xuebao · 2009
A perfect concurrent signature protocol proposed by Huang et al in 2007 is analyzed.Two attacks are given out to show that there are two weaknesses in Huang's protocol: firstly,both participators A and B can change the signed messages after the concurrent signature protocol is completed;secondly,both A and B can forge a concurrent signature themselves.To prevent such forgery attacks,an improved protocol is proposed by adding authentication to the keystone information,and then the security of the improvement is analyzed.