Generalized Anonymous Broadcast Encryption Scheme

Abstract

In this paper, we propose an identitybased, generalized, anonymous broadcast encryption system. This system can be used in a large scale medical database that requires dynamic assignments of access rights because it is both generalized and anonymous. First we design a mechanism to hide the broadcast targets for Boneh’s “Spatial Encryption ”. This mechanism hides the policy vector through the target’s public key. Any receiver can test the ciphertext to see if he is one of the target receivers. If he is not the target, he will not learn the set of target receivers. Then we define suitable security notion for this anonymous broadcast encryption system. Assuming that BDDHE problem is secure, we prove the security of the system in the standard model.