• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.17-30
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• 2016

In this paper, we propose an efficient public key trace and revoke scheme. An trace and revoke scheme is a broadcast encryption scheme which has a tracing and revocation algorithm. It would maintain security of the scheme to revoke pirate keys which are colluded by malicious users. In addition, property of revocation can be applied to various circumstances because it can help cipher text delivered to certain users who are supposed to. In this paper, we would change the scheme[Augmented broadcast encryption scheme] based on the bilinear groups of the composite order into that of prime order and we can improve the size of public key, secret key, ciphertext considerably. Furthermore, we define property of revocation precisely, so we can obtain the result that the scheme with limited revocation can be expanded to have a full revocation. This paper can be easily applied to the organization such as government, military, which has a hierarchical structure.