The Analysis and Improvement of A Certificateless Threshold Proxy Blind Signature Scheme

From the analysis of a certificateless threshold proxy blind signature scheme proposed by Chen Nan et al(Chen Nan, Zhang Jianzhong. A Certificateless-based Threshold Blind Proxy Blind Signature Scheme [J]. Journal of Xianyang normal university, 2013, 28(6): 4-6.), found that there is a problem of the leaking of original signer's key, this will lead to the abuse of signatures. In order to remedy the defect of the original signer's key be discloused, propose a new scheme, and analysis the security of the new scheme. It is proved that the scheme satisfies blindness, at the same time it is also proved that under the random oracle model the new scheme is existentially unforgeable against the two kinds of attackers.