A Short Random Fingerprinting Code Against a Small Number of Pirates

In this paper, we propose a variant of Tardos code which is practical for various applications against a small number of pirates. As an example of our results, for c=5, the code length becomes only 1500 log(1/e) bits while the conventional Tardos code requires 2500 log(1/e) bits, where e is a security parameter. Furthermore our codes do not need a continuous distribution which is needed to construct the original Tardos codes. Our codes are based on a simple random variable drawn from a small set. It implies that it makes to implement and to perform a simulation extremely easier than the original one.