Cipher Text Policy Attribute Based Broadcast Encryption for Multi-Privileged Groups

In the current globalization scenario, many group communication applications have become vital and the users not only subscribe to a single resource, but they use multiple resources and hence ending up with multi-privileged groups. In some group communication applications, it is desirable to encrypt the contents without exact knowledge of the set of intended receivers. Attribute based encryption offers this ability and enforces access policies defined on attributes, within the encryption process. In these schemes, the encryption keys and/or cipher texts are labelled with sets of descriptive attributes defined for the system users, and a particular user private key can decrypt only if the two match. This paper presents a cipher text policy attribute based broadcast encryption scheme for multi-privileged group of users. The proposed scheme has been proved secure using random oracle model.