Two revised coin-based anonymous fingerprinting schemes
Ran Qin · Jisuanji gongcheng yu sheji · 2009
To design more secure and practical anonymous fingerprinting schemes, two revised schemes are introduced, which are motivated by the idea of digital coins introduced in Ref. [1]. The first scheme employs the so-called restrictive blind signature technique. By embedding a Schnorr signature into the coin identifier, it can effectively withstand the framing attack mounted by a collusion of the merchant and the registration center. The main construction of the second scheme is based on several building blocks, i.e., the Camenisch- Lysyanskaya signature scheme, the Damg?rd-Fujisaki commitment scheme, the proof of knowledge protocol for proving that a committed value lies in an interval, etc. Compared with the scheme in Ref. [1], the second scheme is more practical, because it allows the buyer to register only once without the limit on the total number of anonymous purchase. It can be proved that the new schemes fulfill all the chara-cteristics demanded in Ref. [1], i.e., the security for the merchant, the security for the buyer, and the security for the registration center and the anonymity for the buyer.