Fully Collusion Resistant Traitor Tracing with Short Ciphertexts and Private Keys

We construct a fully collusion resistant tracing traitors system with sublinear size ciphertexts and constant size private keys. More precisely, let N be the total number of users. Our system generates ciphertexts of size O( N) and private keys of size O(1). We first introduce a simpler primitive we call private linear broadcast encryption (PLBE) and show that any PLBE gives a tracing traitors system with the same parameters. We then show how to build a PLBE system with O( N) size ciphertexts. Our system uses bilinear maps in groups of composite order.

• Type: Conference
• Year: 2006
• Where: EUROCRYPT
• Authors: Dan Boneh, Amit Sahai, Brent Waters
• Keywords: Cryptology, EUROCRYPT 2006, Private Keys, Size Ciphertexts, Tracing Traitors