Enhanced identity based broadcast encryption scheme through open networks

Abstract

Broadcast Encryption (BE) is concerned with with securing the transmitted messages to a dynamic group of users through any available channels either secured or not secured. This paper provides a scheme for efficient broadcast encryption over open networks using some cryptographic primitives as Aggregatable broadcast encryption (ABE) and Identity Based Encryption (IBE). In the proposed scheme, any user of the group can transmit to any chosen set of the group and only the targeted users can retrieve the message. Any one outside the group who has the public key can transmit to any chosen set from the users and only the valid users can decrypt the message. The proposed scheme is fully collusion resistant which mean that even if all revoked users collude, they can not extract the Key and decrypt the message. The proposed scheme is also used with stateless receivers in which users don't need to update their keys each session. The proposed scheme has lower computations overhead in adding new users compared to that of the Contributory Broadcast Encryption (CBE) and Identity Based Broadcast Encryption (IBBE) over open networks. Another advantage in our porposed scheme is that the users and the Private Key Generator (PKG) are responsible for setting up the scheme. The proposed scheme does not constitute a single point of failure as in IBBE. It also combines between CBE and IBBE to get the best efficiency.