Advanced Colluder Detection for a Family of Anti-Collusion Hiding Codes

In this paper, the authors examine a family of anti-collusion codes using the principle of "Orthogonal Spreading followed by the Inverse Fourier Transform (OSIFT)" as introduced. The Hadamard-Walsh (HW) codes were adopted as the orthogonal spreading codes. Here, they introduce another type of orthogonal spreading codes; namely, the Carrier Inter-ferometry (CI) codes, which are comparable to HW codes. To detect OSIFT hiding codes against weighted collusion attacks, they propose advanced detectors that can identify a large number of colluders with weighted collusion attacks.