新的基于双难题的带有消息恢复的签名方案

A New Signature Scheme with Message Recovery Based on Two Hard Problems

为增强安全性,基于双难题的签名方案相继被提出,如基于离散对数和素因子分解问题的签名方案,其安全目标是只要一个难题未被攻破,方案就是安全.分析表明:如果因子分解问题可解,杨刚和李艳俊提出的基于双难题的方案(YL)将被攻破;如果离散对数问题可解,LI和CHEN的方案(LC)不能抵抗伪造攻击.文中提出一种新的签名方案,该方案是真正同时基于双难题的,并能将消息恢复.通过分析,与其它方案相比,更加高效.

To enhance the security, many signature schemes were designed based on two hard problems, such as factoring and discrete logarithm. The major goal of these schemes is that they cannot he broken if both problems cannot be solved simultaneously. However, --. this paper shows that YL scheme can be broken if the factoring problem is solved, LC scheme is insecure against forgery if the discrete logarithm problem is solved. A new signature scheme is proposed that is really based on two hard problems simultaneously, which can also make the message recovered. Comparing with other schemes, this scheme is more efficient.