关键词: 双向盲代理重签名, 多用性, 盲性, 标准模型, 可证明安全

Abstract: The security of the bidirectional blind proxy re-signature scheme proposed by Deng et al. (DENG Y Q, DU M H, YOU Z L, 〖WTBX〗et al.〖WTBZ〗 A blind proxy re-signatures scheme based on standard model [J]. Journal of Electronics and Information Technology, 2010, 32(5): 1119-1223) was analyzed, and the scheme was found insecure. Meanwhile, a forgery attack on this scheme was given, in which the delegatee could produce the valid signature of the delegator without the help of the proxy. To overcome the weakness of this scheme, an improved blind proxy re-signature scheme was proposed, which was proved secure in the standard model. It can efficiently resist the forgery attack. The delegatee and the proxy can not obtain the contents of the message to be signed in order to better protect the privacy of the message. The proposed scheme is blind, bidirectional, multi-useful, transparent and key optimal.

Key words: bidirectionally blind proxy re-signature, multi-use, blindness, standard model, provable security