In 2005, Bao, et al. [Appl. Math. and Comput., vol.169, No.2, 2005] showed that Tzeng, et al.’s nonrepudiable threshold multi-proxy multi-signature scheme with shared verification was insecure, and proposed an improv...In 2005, Bao, et al. [Appl. Math. and Comput., vol.169, No.2, 2005] showed that Tzeng, et al.’s nonrepudiable threshold multi-proxy multi-signature scheme with shared verification was insecure, and proposed an improved scheme with no Share Distribution Center (SDC). This paper shows that Bao, et al.’s scheme suffers from the proxy relationship inversion attack and forgery attack, and pro- poses an improvement of Bao, et al.’s scheme.展开更多
Abstract In this paper, we give a fast attack against hash function HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto＇92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bi...Abstract In this paper, we give a fast attack against hash function HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto＇92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bit fingerprint. We break the HAVAL with 128-bit fingerprint. The conclusion is that, given any 1024-bit message ra, we just make some modifications about m, and the modified message ra can collide with another message m only with probability 1/2^7, where m = m ＋ △m, in which △m is a fixed difference selected in advance. In addition, two collision examples for HAVAL-128 are given in this paper.展开更多
基金Supported by the National Natural Science Foundation of China (No.10671051)the Natural Science Foundation of Zhejiang Province (No.Y105067).
文摘In 2005, Bao, et al. [Appl. Math. and Comput., vol.169, No.2, 2005] showed that Tzeng, et al.’s nonrepudiable threshold multi-proxy multi-signature scheme with shared verification was insecure, and proposed an improved scheme with no Share Distribution Center (SDC). This paper shows that Bao, et al.’s scheme suffers from the proxy relationship inversion attack and forgery attack, and pro- poses an improvement of Bao, et al.’s scheme.
基金the National Natural Science Foundation of China(Grant No.90304009) the“973 Project”(Grant No.G19990358).
文摘Abstract In this paper, we give a fast attack against hash function HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto＇92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bit fingerprint. We break the HAVAL with 128-bit fingerprint. The conclusion is that, given any 1024-bit message ra, we just make some modifications about m, and the modified message ra can collide with another message m only with probability 1/2^7, where m = m ＋ △m, in which △m is a fixed difference selected in advance. In addition, two collision examples for HAVAL-128 are given in this paper.
