• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.2
• /
• pp.41-47
• /
• 2003

Revocation scheme is a re-keying scheme for dynamically changing group in multicast environment. In this paper, we propose two variants of the previously proposed revocation scheme, on the purpose of reducing the amount of computations group members should perform. Also proposed is a method of allowing unlimited number of member revocations.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.11 no.5
• /
• pp.31-42
• /
• 2001

Two important requirements in broadcast encryption schemes are traitor traceability and revocability. In this paper, we propose a new type of a traitor tracing scheme that can revoke an unlimited number of traitors\` personal keys. Additionally, we propose an efficient and simple method to provide self-enforcement property. We also describe a variant of our scheme of which encryption algorithm is secure against adaptive chosen ciphertext attacks.