分析了大多数RSA门限群签名方案存在的缺陷,RSA的模数是n,φ(n)是秘密参数,参加部分签名的成员无法知晓,求Lagrange相关系数存在困难,也为建立门限RSA密码体制带来困难。提出一种新的方案以克服上述困难,通过求n。无须在求Lagrange相关系数时进行求逆运算,使该方案在保证安全的前提下变得可行实用。
The thesis analysized the weakness of most RSA group threshold signature. Partial signaturer couldn' t know the secret parameter φ(n) so that it was difficult to get the value of Lagrange coefficient. A technique to overcome the difficulty was proposed that it was group signature combiner' s duty to get the value of Lagrange coefficient. Furthemore, it needn' t invert any element by getting the value of a~ when gets the value of Lagrange coefficient, which makes the scheme safe and workable