摘要
Hash函数已经被广泛用于各种数字签名方案中。在基于零知识概念的数字签名方案中,方案发明者宣称:所使用的Hash值的长度短至64-bits或72-bits即可达到2-64或者2-72的安全度。文中研究表明,在数字签名中由于存在来自签名者的生日攻击,如此短的Hash值并不能达到规定的安全度。并提出了一个简单的修改方案,使得在不增加计算复杂性的情况下来达到规定的安全度。
Hash function has already been applied in all kinds of digital signature schemes. In digital signature schemes based on the zero- knowledge concept, it has been claimed that the length of Hash - values could be as short as 64 or 72 bits for the security of 2^-64 or 2^-72. Shows that signature schemes with such short Hash - values cannot achieve the stated security levels, due to the birthday attack by the signer. A simple modification is also presented, where the stated security levels can be obtained without increase of computational load.
出处
《计算机技术与发展》
2007年第6期170-172,共3页
Computer Technology and Development
基金
安徽省教育厅自然科学基金资助项目(2006KJ017C)
关键词
数字签名
单向HASH函数
零知识证明
digital signature
one - way Hash function
zero - knowledge proof
