Cryptanalysis of Three Blind Proxy Multi-signature Schemes
Wang Tian-yin①②; Liu Mai-xue①; Wen Qiao-yan②
①School of Mathematical Science, Luoyang Normal University, Luoyang 471022, China;②State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China
Abstract:Through the cryptanalysis of three blind proxy multi-signature schemes, it shows that in Li Yuan et al.’s scheme, any original signer can sign a valid blind proxy multi-signature by the means of forging proxy key, and in Kang Li et al.’s first type blind proxy multi-signature scheme, attacker not only can forge any proxy signer’s proxy sub-key, but also can forge blind proxy multi-signatures on any message, and in Kang Li et al.’s second type blind proxy multi-signature scheme, attacker can sign a valid blind proxy multi-signature by the means of forging proxy key, therefore the three schemes are not secure.