Fast Multivariate Signature Generation in Hardware: The Case of Rainbow

This paper deals with the design of an area-time efficient hardware architecture for the multivariate signature scheme, Rainbow. As a part of this architecture, a high-performance hardware optimized variant of the well-known Gaussian elimination over GF(2^l) and its efficient implementation is presented. Besides solving LSEs, the architecture is also re-used for the linear transformation operations of the scheme, thereby saving on area. The resulting signature generation core of Rainbow requires 63,593 gate equivalents and signs a message in just 804 clock cycles. A comparison of our architecture with implementations of the RSA, the ECDSA and the en-TTS scheme shows that Rainbow in hardware provides significant performance improvements.