BSADF: Blind Signature Based Anonymous Digital Fingerprint

The security threats and system weakness of present digital fingerprint schemes were analyzed. Combining blind signature and digital fingerprint, an asymmetric digital fingerprint scheme with conditional anonymity based on elliptic curves cryptosystem was presented. The probabilistic encryption algorithm and identity blinding process enable the buyer to be conditionally anonymous in fingerprint embedding and commodity purchasing, and the anonymity can also be conveniently revoked if necessary. By utilizing probabilistic encryption algorithm in fingerprint generating, the scheme avoids the relevance between different digital fingerprints generated by the same party, and effectively prevents coalition attack and generalized fingerprint forgery. Further analyses and comparison with other digital fingerprint schemes also justify the scheme's brevity, security, high efficiency, and thus considerable improvement on system overheads regarding software and hardware application environment.