Lightweight CRC-based Message Authentication

Low-cost resource-constrained devices can allocate very limited resources for implementing security. At the same time, they still require some level of protection. In this paper, we present a lightweight message authentication scheme based on Cyclic Redundancy Check (CRC). The presented CRC inherits the implementation simplicity of the conventional CRC checksum except that the LFSR implementing its encoding and decoding is made re-programmable. Similarly to previously proposed cryptographic CRCs, it detects both random and malicious errors without increasing bandwidth. The main difference from previous approaches is that we use arbitrary instead of irreducible generator polynomials. This eliminates the need for irreducibility tests. We provide a detailed quantitative analysis of the achieved security as a function of message and CRC sizes. The results show that the presented scheme is particularly suitable for the authentication of short messages.