代理签名及其前向安全性研究

【作者】 王亮；

【导师】 贾小珠；

【作者基本信息】 青岛大学 ， 计算机应用技术， 2008， 硕士

【摘要】 数字签名技术是网络信息安全中一种非常重要的技术,其在电子商务中具有重要应用。而代理签名的出现,给出了一种在电子化的信息社会里权力委托的方法。由于代理签名在电子现金、电子股票、移动代理及电子商务等方面有广泛的应用前景,一提出便受到人们的广泛关注。同数字签名一样,代理签名的安全性取决于两个方面:代理签名体制的抗攻击性和签名密钥的安全性。根据Kerckhoff假设,密码体制总是公开的,因此代理签名的安全便依赖于签名密钥的安全性上。一旦密钥泄露,整个签名体制便变得不再安全,因此如何减少密钥泄漏带来的危害便成为人们所关心的问题。解决密钥泄露的一种新思路是前向安全思想。前向安全的目标是通过密钥进化来减少密钥泄漏带来的损失。本文主要在代理签名和前向安全性的基础上,对前向安全性代理签名进行了研究,所取得的成果如下:1.将前向安全性思想与代理签名体制相结合,通过在代理签名体制中增加密钥进化过程,使代理密钥具有前向安全性,给出了基于离散对数的前向安全代理签名和基于椭圆曲线密码体制的前向安全代理签名方案。2.针对前向安全代理签名能保证密钥泄露前签名的安全性,却无法阻止攻击者后续签名的缺点,对强前向安全性代理签名进行了研究。给出了两种强前向安全代理签名方案:基于陷门信息的自更新密钥强前向安全代理签名和交互式密钥更新强前向安全代理签名方案。更多还原

【Abstract】 Digital signature technology is of great importance in the network information security techniques and plays an important role in electronic commerce.Proxy signature provides methods to right commission in the electronic information society.Because of its spreading applied vista in electronic cash,electronic stocks,mobile agent and substitute product of electronic commerce,proxy signature was given extensive attention after proposed.Proxy signature,same as digital signature,its security depends on two aspects: anti-attack ability of proxy signature scheme and safety of the signature key.According to the Kerckhoff hypothesis,cryptosystem is always open,so the security of proxy signature is determined by the security of signature secret key.Once the secret key exposes,the whole signature scheme will be not safe any longer,so how to decrease the harm brought by the key becomes a concerned problem.A new idea of solving key exposures is forward secure idea.The aim of forward secure is to reduce the loss brought by key exposures.On the basis of proxy signature and forward-security,the forward-secure proxy signature was studied in this paper,our achievements are as follows:First,the idea of forward secure and proxy signature scheme were combined together. By adding key evolution process in proxy signature scheme,we gave the forward-security to the proxy signature key,provided forward-secure proxy signature based on discrete logarithm and forward-secure proxy signature based on elliptic curve key scheme.Second,forward-secure proxy signature can guarantee the key’s safety before key exposures,while it can’t prevent subsequent signature by the attacker.Based on this,we put the research on strong forward-secure proxy signature.Two strong forward-secure proxy signature schemes were given:self-updating strong forward-secure proxy signature based on trapdoor information and interactive strong forward-secure proxy signature.更多还原