论文部分内容阅读
Matsumoto等提出了两个利用不安全服务器辅助的方法加速秘密计算的协议,这两个重要协议使得智能卡在卡持有者不必相信的服务器的帮助下,更快地进行秘密RSA计算,从而使得RSA签名可由一个智能卡来完成,并认为,如果RSA是安全的,则这些协议只能通过在某空间中穷尽搜索来攻击。对其中的协议一已有人给出了攻击方法,使所需的搜索空间极大减小。本文对协议二给出有效的攻击方法,减少了该协议的安全比特数,极大地减小搜索空间。为抵抗该攻击,本文还讨论了协议的参数选取。
Matsumoto et al. Proposed two protocols that use unsafe server-assisted methods to speed up clandestine computing. These two important protocols allow smart cards to perform clandestine RSA computations faster with the help of a server that the cardholder does not have to trust, thereby enabling RSA Signatures can be done by a smart card and believe that if RSA is secure, these protocols can only be attacked by exhaustive search in a space. One of the protocols among them has been given a method of attack, which greatly reduces the required search space. In this paper, we give an effective attack on Protocol II, reduce the number of security bits in the protocol and greatly reduce the search space. In order to resist the attack, this article also discusses the parameters of the protocol selection.