Cryptanalysis of a Generalized Anonymous Buyer-Seller Watermarking Protocol of IWDW 2004

Abstract

Abstract.In this paper, we analyze the security of a generalized anonymous buyer-seller watermarking protocol recently proposed by Choi and Park at IWDW 2004. We prove that it has not met the designers' intended security criteria by showing that an attacker can actually: (1) discover the unique buyer's watermark which was chosen by the watermark certificate center (W CC), and (2) decrypt the encrypted watermarked digital content without any extra cost. Also, it is surprising to note that when designing their protocol, the designers did not take into consideration the conspiracy attacks.

(In)Security of an Efficient Fingerprinting Scheme with Symmetric and Commutative Encryption of IWDW 2005

“…We caution against simple fixes that patch our attacks in this paper since experience has shown that the break-and-fix cycle loops indefinitely, for instance see [17][18][19][30][31][32] where attacks were applied to protocols [8-11, 20, 22, 6, 36] that improved on existing ones. We suggest instead, that if BSW schemes are required, to consider other schemes like [24,38] that have not yet been shown to fall to any attacks that counter their design goals.…”

“…Meanwhile, a few subsequent BSW schemes proposed with different additional features like anonymity [20], without trusted third parties (TTP) [10] and extension for multiple purchases [11] were later found to have security problems [10,19,18]. A few more recent schemes can be found in [24,37,38].…”

Analysis of a Buyer–Seller Watermarking Protocol for Trustworthy Purchasing of Digital Contents

“…[14] presented a protocol that also protects the buyer's privacy. Several buyer-seller protocol variants have been constructed since then, including the protocols proposed in [1], [2], [5], [6], [8], [9], [12], [13], [15], [16], [17], [21], and subsequent analyses appear in [10], [11], [20], [24], [5,4,23].…”