数字产品中新的无诬陷的2-安全码

该文研究的是两类防盗版码——TA码和安全码．作者利用等距等重码构造了新的2-TA码和2-安全码，并通过分别级联前面得到的两个2-安全码与一个Reed-Solomon码得到了两个2-安全码．当码字的个数相同时，这两个码的码长比Boneh等人的方法中的级联码的码长要短．这两个码应用Koetter-Vardy软判断列表算法作为追踪算法，与Boneh等人的追踪算法相比，这个新的追踪算法不会诬陷别的用户；与Barg等人的算法相比，这个追踪算法在许多情况下一定可以找到两个叛徒，并且算法失败的概率非常小．

The New 2-Secure Codes Without Frame in Digital Products

In this paper, we talk about two kinds of fingerprinting code.First we construct a 2-TA code. The code improved the known condition (in [1]) on constructing 2-TA codes, which is d >3n4,where d and n represent the Hamming distance and length of the code, then we show several codes with constant weight and distance are 2-secure codes. The new traitor tracing algorithm of these codes only have little possibility of failure, i.e.outputs nothing. But in [3], the traitor tracing algorithm will frame some innocent users. At last by concatenating codes having constant Hamming distance and weight got above with one Reed-Solomon code, we obtain two 2-secure codes. The two codes have smaller code lengths than codes in [3], when they have the same code numbers and tracing errors. The tracing algorithms have two steps, first we decode pirate vector, thus we could get vectors which are composed by inner codes, i.e. codes with constant weight and distance; second we decode vectors got from last step using Koetter-Vardy soft-list-decoding algorithm. We could now identify traitors using some rules. The new tracing traitor algorithm cannot frame inncent users and the possibility of failure is small. Sometimes they have nice tracing ability, i.e. identify two traitors, which improve the ability of tracing algorithm in [10].