无证书离线电子现金方案

在联盟结构生成过程中，同势的2个联盟通常具有相同值或相似值。在同势同值情况下建立不同联盟的限界时，必须搜索势结构图的最底两层。研究最优势结构生成问题，提出一种给定限界的势结构生成算法，确定需要进一步搜索的势结构。分析结果表明，搜索势结构图的最底两层和顶层后，通过搜索势结构集合，可以得到符合要求的限界。与其他势结构生成算法相比，该算法需要搜索的势结构数最少。

Certificateless off Line Scheme for Electronic Cash

During the generating process of coalition structure, two coalitions with same cardinality always have same value or similitude value. It is necessary to search the lowest two levels of the cardinality structure graph while establishing a bound of different coalition with same cardinality and same value. This paper researches the problem about best cardinality structure generating, proposes an algorithm for cardinality structure generating with bound and ascertains cardinality structures need to be further searched. Analysis results show that the required bound can be achieved by searching the cardinality structure set after searching the lowest two levels and the top level of the cardinality structure graph. The number of cardinality structures for searching of this algorithm is minimal comparing with other algorithms for cardinality structure generating.