Broadcasting secrets in communication networks

Abstract

One property of a broadcast channel is that a single message broadcasted from an originator may be received simultaneously by several recipients in communication links. Based on the Chinese remainder theorem (CRT), we propose a new secure broadcasting scheme to distribute different secrets in one single broadcasting transaction such that each of the secrets is dedicated to different authorized recipients. On receiving the ciphertext broadcasted by the originator, only authorized recipients can obtain and authenticate their dedicated secrets individually, while no secret is revealed to unauthorized recipients. In a single broadcasting transaction, each authorized recipient cannot know who are the other intended recipients for this transaction. Furthermore, the processes for decryption and authentication of the dedicated secret are performed through simple arithmetic computation, i.e., modular operations, hence it is suitable for the applications that the recipient has less computing power. We also show that the proposed scheme can withstand the attack on replaying a previously intercepted broadcasting message.