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

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. at and Choi et. at...

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Main Authors: Goi, , BM, Siddiqi, , MU, Deng, , RH, Bao,, F, Yang, , YJ, Phan, , RCW
Format: Article
Published: 2004
Subjects:
Online Access:http://shdl.mmu.edu.my/2500/
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author Goi, , BM
Siddiqi, , MU
Deng, , RH
Bao,, F
Yang, , YJ
Phan, , RCW
author_facet Goi, , BM
Siddiqi, , MU
Deng, , RH
Bao,, F
Yang, , YJ
Phan, , RCW
author_sort Goi, , BM
building MMU Institutional Repository
collection Online Access
description 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. at and Choi et. at 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. at's 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 buyer's 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.
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spelling mmu-25002011-08-22T02:44:06Z http://shdl.mmu.edu.my/2500/ Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity Goi, , BM Siddiqi, , MU Deng, , RH Bao,, F Yang, , YJ Phan, , RCW QA75.5-76.95 Electronic computers. Computer science 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. at and Choi et. at 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. at's 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 buyer's 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. 2004 Article NonPeerReviewed Goi, , BM and Siddiqi, , MU and Deng, , RH and Bao,, F and Yang, , YJ and Phan, , RCW (2004) Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity. APPLIED CRYPTOGRAPHY AND NETWORK SECURITY, PROCEEDINGS , 3089 . pp. 369-382. ISSN 0302-9743
spellingShingle QA75.5-76.95 Electronic computers. Computer science
Goi, , BM
Siddiqi, , MU
Deng, , RH
Bao,, F
Yang, , YJ
Phan, , RCW
Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
title Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
title_full Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
title_fullStr Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
title_full_unstemmed Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
title_short Cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
title_sort cryptanalysis of two anonymous buyer-seller watermarking protocols and an improvement for true anonymity
topic QA75.5-76.95 Electronic computers. Computer science
url http://shdl.mmu.edu.my/2500/