摘要： 提出了TLS 协议组（SSL 3.0 和TLS 1.0 及其衍生的系列协议）共同存在的一个安全缺陷：密文的最前面4 个字节其底码是可以猜测的。攻击者利用该缺陷蛮力搜索密钥攻击该类协议时可以大幅度减少工程量。给出了协议改进方案；针对改进前后的协议，详细描述了蛮力攻击方法，并进行了攻击复杂度分析。
关键词:
TLS 协议组；SSL；TLS；流密码；分组密码
Abstract: This paper at first introduces a security weakness which the first four encrypted bytes can be guessed in TLS protocol group. Using it the computational amount of a brute force attack on these protocols may be greatly reduced. This paper proposes a modification to conquer this weakness and elaborates the brute force attack method and its computational complexity
Key words:
TLS protocol group; Secure socket layer (SSL); Transport layer security (TLS); Stream cipher; Block cipher
徐 强，司天歌，戴一奇. TLS 协议组密底泄露缺陷及改进[J]. 计算机工程, 2006, 32(10): 123-124,127.
XU Qiang, SI Tiange, DAI Yiqi. Weakness and Improvement of Encrypted Messages Guessed in TLS Protocol Group[J]. Computer Engineering, 2006, 32(10): 123-124,127.