A Robust Collaborative Threshold Authenticated Encryption Scheme Based on Message Blocking

In recent years, some collaborative threshold authenticated encryption schemes were put forward to ease the workloads of the individual signers. Unfortunately, the original scheme was found to have design flaws in its signature generation phase, however the improvements of the original one are all proved to be inefficient. In order to remedy the security flaws and improve the performance, a novel robust collaborative threshold authenticated encryption scheme is proposed in this paper. Based on the elliptic curve cryptography and the message linkage technology, this scheme can realize efficient encryption and authentication of large messages. Analysis shows that the proposed scheme is theoretically correct and has better performance. The scheme can be further applied into distributed environments, such as cloud storage and computing networks, dynamic alliance of enterprises and virtual organizations.