Construction of an Asymmetric Traitor Tracing Schemes with Anonymity
Moon‐Sik Lee, Kang Sunbu, Juhee Lee · Information Security and Cryptology · 2012
ABSTRACT Traitor tracing schemes deter traitors from sharing their private keys by tracing at least one of the subscribers who were implicated in the construction of a pirate decoder. In general, it is assumed that the system manager in the scheme generates and distributes the subscribers' private key. But if the system manager knows the subscribers’ private keys, he cannot convinc e a third party of a certain subscriber’s piracy. To solve this p roblem, the system manager should not know the whole parts of subscribers’ private keys and this leads to researches of asymmetric schemes. Moreover for the purpose of enhancing subscribers’ privacy, there were two proposals of introducing a nonymity onto asymmetric traitor tracing schemes, but one of them turned out to be a failure. In this paper, we point out th at the other proposal also has flaws. We consider how to introduce anonymity to traitor tracing schemes, as a result, we suggest a new framework which is practical. We also construct a scheme by using an anonymous credential system and an asymmet ric traitor tracing scheme. We prove the security of our scheme and consider the typical applications.Keywords: Broadcast encryption, Traitor Tracing, Anonymity접수일(2012년 3월 8일), 수정일(1차: 2012년 9월 6일), 게재확정일(2012년 10월 12일)† 주저자, [email protected]‡ 교신저자, [email protected]