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].