【作者】 任艳丽； 谷大武；

【Author】 Ren Yanli Gu Dawu Dept.of computer science and engineering,Shanghai Jiaotong University,shanghai,200240

【机构】 上海交通大学计算机科学与工程系；

【摘要】 认证性与保密性是密码学的基本功能。签密方案能同时实现加密与签名,且实现代价小于两者之和。可证明安全是证明密码方案安全性的一种有效的方法。据我们所知,所有可证明安全的签密方案都基于椭圆曲线上的双线性对与对称加密算法。本文基于离散对数问题,提出了一个可证明安全的公钥签密方案。它实现了选择密文攻击下的密文不可区分性与选择消息攻击下的签密不可伪造性。而且,方案还具有不可否认性与公开可验证性。与 ElGamal 先签名后加密方案相比,此签密方案效率更高。更多还原

【Abstract】 Confidentiality and authentication are essential functions of cryptography.Signcryption scheme can realize both the functions of secure encryption and digital signature,and with a cost smaller than that required by sign-then-encryption.Provable secure is one of the methods to prove the security of cryptographic schemes.In our knoeledge,all of the provably secure signcryption schemes use bilinear pairings based on elliptic curve and symmetric encryption algorithms.In this paper,we propose a provably secure public key signcryption scheme based on discrete logarithm problem.It provides indistinguishability of ciphertext under adaptive chosen ciphertext attack and unforgeability of the signcryption under adaptive chosen message attack.Moreover,the scheme has the properties of non-repudiation and public verification without the receiver.In addition,the scheme has smaller computation and shorter length of the ciphertext compare to EIGamal signature-and-encryption scheme.更多还原