On Crafty Pirates and Foxy Tracers

Piracy in digital content distribution systems is usually identified as the illegal reception of the material by an unauthorized (pirate). device. A well known method for discouraging piracy in this setting is the usage of a traitor tracing scheme that enables the recovery of the identities of the subscribers who collaborated in the construction of the pirate decoder (the traitors). An important type of tracing which we deal with here is "black-box traitor tracing" which reveals the traitors' identity using only black-box access to the pirate decoder. The only existing general scheme which is successful in general black-box traitor tracing was introduced by Chor Fiat and Naor. Still, this scheme employs a pirate decoder model that despite its generality it is not intended to apply to all settings. In particular it is assumed that (1) the pirate decoder is "resettable", i.e. the tracer is allowed to reset the pirate decoder to its initial state after each trial (but in many settings this is not possible: the pirate decoder is "history-recording"), and that (2) the pirate decoder is "available", i.e. it does not employ an internal reactive mechanism that, say, disables the tracing process (such as shutting down) -- we will call such reactive decoders "abrupt."In this work we discuss pirate-decoders of various types which we categorize according to their capabilities: resettable vs. history recording, and available vs. abrupt. These (crafty) pirate decoders of "enhanced capabilities" (compared to the model of Chor et al.) appear in many plausible piracy scenarios. We then present new (foxy) black-box traitor tracing schemes which cope with such pirate decoders. We present a generic black box traitor tracing technique against any abrupt/resettable decoder. This generic tracing method can be implemented readily in a linear ciphertext size traitor tracing scheme. By employing a new relaxation technique, which we call list-tracing, we describe a traitor tracing scheme with sublinear ciphertext size that is successful against abrupt/resettable pirate decoders. Finally, we present the first black-box traitor-tracing scheme and techniques that are successful against abrupt/history-recording pirate decoders (in the multimedia transmission setting).

[1]  Moni Naor,et al.  Revocation and Tracing Schemes for Stateless Receivers , 2001, CRYPTO.

[2]  Robert E. Tarjan,et al.  Resistance of digital watermarks to collusive attacks , 1998, Proceedings. 1998 IEEE International Symposium on Information Theory (Cat. No.98CH36252).

[3]  Birgit Pfitzmann,et al.  Asymmetric fingerprinting for larger collusions , 1997, CCS '97.

[4]  Jessica Staddon,et al.  Efficient Methods for Integrating Traceability and Broadcast Encryption , 1999, CRYPTO.

[5]  Markus G. Kuhn,et al.  Low Cost Attacks on Tamper Resistant Devices , 1997, Security Protocols Workshop.

[6]  Jirí Sgall,et al.  Efficient dynamic traitor tracing , 2000, SODA '00.

[7]  Aggelos Kiayias,et al.  Self Protecting Pirates and Black-Box Traitor Tracing , 2001, CRYPTO.

[8]  Amit Sahai,et al.  On the (im)possibility of obfuscating programs , 2001, JACM.

[9]  Yvo Desmedt,et al.  Optimum Traitor Tracing and Asymmetric Schemes , 1998, EUROCRYPT.

[10]  Douglas R. Stinson,et al.  Combinatorial Properties and Constructions of Traceability Schemes and Frameproof Codes , 1998, SIAM J. Discret. Math..

[11]  Birgit Pfitzmann,et al.  Trials of Traced Traitors , 1996, Information Hiding.

[12]  Birgit Pfitzmann,et al.  Asymmetric fingerprinting , 1996 .

[13]  Amos Fiat,et al.  Dynamic Traitor Training , 1999, CRYPTO.

[14]  Moni Naor,et al.  Threshold Traitor Tracing , 1998, CRYPTO.

[15]  Dan Boneh,et al.  Collusion-Secure Fingerprinting for Digital Data (Extended Abstract) , 1995, CRYPTO.

[16]  Matthew K. Franklin,et al.  An Efficient Public Key Traitor Tracing Scheme , 1999, CRYPTO.

[17]  Reihaneh Safavi-Naini,et al.  Sequential Traitor Tracing , 2000, CRYPTO.

[18]  Moni Naor,et al.  Efficient Trace and Revoke Schemes , 2000, Financial Cryptography.

[19]  Amos Fiat,et al.  Tracing traitors , 2000, IEEE Trans. Inf. Theory.