一种2-安全码的改进追踪算法

完全安全码是不存在的，这已经从理论上得到证明。也就是说，任何安全码在某一种情况下，对叛逆者的追踪必定失败。有一种追踪效率很高的2-安全码，当然它在某种特殊情况下也无法实现对叛逆者的追踪。文中改进了该算法，使得追踪效率更高。而且通过Hash函数实现在这种特殊情况下对叛逆者的追踪，因此，可以实现对每个盗版码字的追踪。

An Improved Traitor Tracing Algorithm for a 2_Secure Code

Non-existence of fully secure code has been proved in theory. That is to say, any secure code is bound to fail to trace traitors in some case. There is a 2_secure code with efficient tracing capability. It can not trace traitors in a special case, of course. In this paper, the algorithm is such improved that the taceablity is more efficent. Futhuremore, traitors can be traced in the special case by hash function, so for every pirate codeword, the traitors can be traced.