An efficient traitor tracing scheme for broadcast encryption
Maki Yoshida, Toru Fujiwara · 2002
An efficient traitor tracing scheme for broadcast encryption is proposed. Its security depends on the difficulty of discrete logarithm problem and is equivalent to ElGamal public-key cryptosystem even when subscribers collude. The proposed scheme is the first one which satisfies all the following features: the tracing algorithm is black box tracing; all the traitors are identified from a captured pirate decoder; the data supplier can encrypt the contents such that only a specific subset of subscribers' decoders can decrypt it; the encryption algorithm is public-key.