Traitor Tracing against Public Collaboration

Abstract. Broadcast encryption provides a convenient method to distribute digital content to subscribers over an insecure broadcast channel. Traitor tracing is needed because some users may give out their decryption keys to construct pirate decoders. There are many traitor tracing schemes based on collusion secure codes and identifiable parent property codes. However, these schemes are subject to public collaboration of traitors, which is presented by Billet and Phan in EUROCRYPT 2009 as an attack against code-based traitor tracing schemes. In this paper, we describe a generic collusion secure codes based scheme secure against such collaboration. Our scheme is motivated by the idea of identity-based encryption with wildcards (WIBE). We regard the collusion secure codeword for each user as his/her identity, and issue private key accordingly. When in broadcasting, we use a special pattern of WIBE, namely all bit positions in the codewords of intended receivers are set as wildcards. When...

• Type: Journal
• Year: 2011
• Where: ISPEC
• Authors: Xingwen Zhao, Fangguo Zhang
• Keywords: Broadcast Encryption, ISPEC 2011, Pirate Decoders, Public Collaboration, Security Privacy