Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/3709

Title

Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity

Author(s)

Bao, Feng;  Deng, Robert H.;  Goi, Bok-Min;  Phan, Raphael C-W.;  Siddiqi, M. U.;  Yang, Yanjiang

Abstract

By combining techniques of watermarking and fingerprinting, a sound buyer-seller watermarking protocol can address the issue of copyright protection in e-commerce. In this paper, we analyze the security of two recent anonymous buyer-seller watermarking protocols proposed by Ju et. al and Choi et. al respectively, and prove that they do not provide the features and security as claimed. In particular, we show that i) the commutative cryptosystem used in Choi et. als protocol fails to prevent the watermark certification authority (WCA) from discovering the watermark (fingerprint) chosen by the buyer; ii) for both protocols, the seller can discover the watermark chosen by the buyer if he colludes with the WCA. Hence, these protocols cannot guard against conspiracy attacks. We further show that these protocols only provide partial anonymity, ie. the buyers anonymity is guaranteed only if WCA is honest. Our results suggest that the security of these protocols must assume the honesty of WCA, contrary to the designers original claim. Finally, we propose a new anonymous buyer-seller watermarking protocol which is more secure and efficient, and provides true anonymity.

Publication type

Conference paper

Research centre

Swinburne University of Technology. Sarawak School of Engineering

Source

2nd International Conference, ACNS 2004, Yellow Mountain, China, June 8-11 2004, Vol. 3089 (2004), pp. 369-382

Publication year

2004

Publisher

Springer-Verlag Berlin

Format

pp. 369-382

Publisher URL

2nd International Conference, ACNS 2004, Yellow Mountain, China, June 8-11 2004

Publisher URL

http://dx.doi.org/10.1007/b98360

Copyright

Copyright 2004

Peer reviewed