A collusion-secure fingerprinting code reduced by Chinese remaindering and its random-error resilience

Abstract

A c-secure code with ε-error is one of the fingerprinting codes robust against a collusion attack. The purpose of this study is to construct a new c-secure code which has a shorter code length for a largescale collusion than ever proposed. We call this code a c-secure CRT code. Furthermore, we investigate possible approaches to make this code robust against random-error addition. Two approaches to this problem have already been proposed. One is a combination of an error-correcting code and a c-secure code. The other is to make inner codes of the c-secure code resilient against random-error addition. We propose a brand-new approach, called weak ID elimination, which is a modification of its outer code. We also propose a method to estimate whether the size of a coalition exceeds the traceability of this code.