基于随机哈希签名模式的可信捐赠监督方案

Trustable donation monitor schemes based on randomized Hash signature scheme

通过修改随机数的选取方式,对RMX随机哈希签名算法进行强化,使算法不需要假定签名者是诚实的.基于该强化算法设计了2个可信的捐赠监督方案.当捐赠人愿意透露捐赠数额时,可构建出一个精确捐赠监督方案,任意2名捐赠人可通过比较彼此得到的捐赠总数来判断慈善机构是否公布出正确的捐赠总数.当捐赠人不方便透露捐款数额时,利用强化后的RMX签名算法和百万富翁问题设计了一个模糊捐赠监督方案,捐赠人同样可以监督慈善机构.分析结果表明,慈善机构作假和恶意捐赠人诬陷慈善机构的计算复杂度均为O(2n/2),其中n表示方案中使用的哈希函数输出散列值的长度.当n>160bit时,方案在现有计算能力下是足够安全的.

An enhanced RMX randomized Hash signature scheme is developed through changing the elective mode of the random value, which does not need the presupposition that the signer should be honest. Based on the enhanced scheme, two trustable donation monitor schemes are put forward. When the donators agree to reveal the donations, an accurate donation monitor scheme can be proposed. Through comparing the received donations, any two donators can judge whether the charity proclaims the right total number of the donation or not. When the donators refuse to reveal the donations, an ambiguous donation monitor scheme is advanced based on the enhanced RMX scheme and the millionaires＇ problem. And the donators also can supervise the charity. The analysis results demonstrate that the computation complexities with lying by the charity and forging by the evil donators are both O（2^n/2 ）, where n is the output length of the Hash function. Thus, these schemes are secure enough under the existing computer power when n 〉 160 bit.