Protection of digital property has become crucial due to the widespread use of digital media and communication systems. A lot of research work has been invested into the design of methods that technically support the copyright protection of digital data. Digital Fingerprinting schemes are an important class of these techniques. They do not require tamper-resistant hardware. i.e., they do not belong to the class of copyright protection methods, which prevent copying. The goal of digital fingerprinting is to deter people from illegally redistributing digital data. In other words, digital fingerprinting schemes are technical means to discourage people from illegally redistributing the digital data they have legally purchased. These schemes enable the original merchant to identify the original buyer of the digital data. There are different classes of fingerprinting schemes called symmetric and asymmetric. Classical fingerprinting schemes are symmetrical in the sense that both the merchant and the buyer know the fingerprinted copy. Thus, if another copy with this fingerprinted turns up, one cannot really assign responsibility to one of them. This problem is overcome by asymmetric scheme. Here, only the buyer knows the fingerprinted copy; where the buyer also inputs a secret key and the merchant does not see the fingerprinted copy that this buyer obtains. Only if he finds this copy after, he can extract the proof. However the drawback of this solution is that the merchant knows the buyerfs identity even if the buyer is honest. To protect buyerfs privacy, later anonymous fingerprinting was introduced. The idea is that the merchant can know neither the fingerprinted copy not the buyerfs identity. As it is desired that electronic market places offer privacy to the customers in real-life market place, anonymous fingerprinting schemes are much utility value of digital contents copyright protection in real world. We are concern with more secure and efficient anonymous fingerprinting, and we are making research of strengthening the functionality on an anonymous fingerprinting scheme in various ways.
Papers
JaeGwi Choi, Kouichi Sakurai, JiHwan Park,
"An Efficient Anonymous Digital Fingerprinting Scheme For Multiple Purchases Using Message Recovery Signature",
Korea Information Securtiy Society , Feb. 2003.
JaeGwi Choi, Kouichi Sakurai, JiHwan Park,
"An Efficient Fingerprinting Scheme with Proxy Signatures",
SCIS 2003, Jan. 2003. (in Japanese)
JaeGwi Choi, Kouichi Sakurai, JiHwan Park,
"Improved Anonymous Fingerprinting Scheme with a Robust Asymmetry",
Multimedia Technology and Its Applications, Jan. 2003.