This paper proposes a new public - key encryption scheme which removes one element from the public - key tuple of the original cramer - shoup scheme 这里的标准模型指的是不利用随机预言机这一工具来论证体制安全性的模型。
2.
2 ) second , we develop an efficient identification scheme based on ( the basic and a variation of ) cramer - shoup ' s test function 抗重设攻击身份识别方面，本文设计了一个基于cramer - shoup测试函数(包括cramer - shoup基本方案和变种)的身份设别方案。
3.
5 ) in the aspect of uowhf discovery , tree - shoup construction is put forward in this paper . the construction is based on shoup construction , but need only less random masks and makes uowhf more practical 5 ） 、在uowhf探讨方面，提出了基于shoup结构的树- shoup结构算法，进一步减少了uowhf构造算法需要的随机掩码总数，使uowhf更适合实用。
4.
The scheme is more efficient than the basic cramer - shoup ' s encryption scheme while its security against adaptive chosen cipher - text attack can be proved under the hardness assumption of decisional difhe - hellman problem . 2 . study existing digital signature and develop an efficient digital signature based on certificate data 在分析基本数字签名方法的基础上，设计并实现了基于离散对数困难问题( dlp ) ，辅以hash函数和公钥证书进行签名和验证签名的数字签名方法。
