Expiration Dated Fingerprinting

This paper proposes a new anonymous fingerprinting scheme for continuing the buyer´s privacy protected after expiration of copyright. The proposed scheme guarantees the buyer´s ability to remove an embedded fingerprint from the purchased data item when its copyright is expired. This means that any buyer can freely use the legally purchased data item under anonymity after the copyright is expired. In this sense, our scheme has an enhanced security in terms of the buyer´s privacy.