Weakness and Improvements of Yong-Lee's Anonymous Fingerprinting Protocol
Youngkwan Lee · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences · 2006
In 2005, Yong and Lee proposed a buyer-seller fingerprinting protocol using symmetric and commutative encryptions. They claimed that their protocol was practical and anonymous since they used symmetric and commutative encryptions. However, an attacker can get the content embedded with one or more honest buyers' fingerprints using man-in-the-middle attack. In this letter, we point out the weakness and propose methods for improving to their protocol.