A fast prekeying-based integrity protection for smart grid communications

In this article, we propose a prekeying-based integrity protection mechanism for critical smart grid communications that are often left unprotected due to tight timing constraints. Our mechanism computes the key for the next message in advance followed by a simple exclusive-or operation with the message when it is generated. This provides both integrity and confidentiality at a very low latency cost. The rigorous security analysis shows that the proposed method is secure against cyclic redundancy check (CRC) and message replay attacks. The extensive evaluation shows that the method is up to 21 times faster than standard integrity protection algorithms, and can do the message encryption in under 1 ms even on a very low-end microcontroller.