Frameproof codes against limited coalitions of pirates
If Gamma(p) is a p-ary code of length n and a, b and c are three codewords, then e is called their descendant if e(i) is an element of {a(i),b(i),c(i)} for i = 1,...,n. We are interested in codes Gamma(p) with the property that for any three codewords their only descendant codewords are themselves: this forbids a coalition of three users, given codewords a, b and c from framing a fourth user given the codeword e. (C) 2002 Elsevier Science B.V. All rights reserved.
codes digital fingerprinting hadamard