The SHA1 core from Alma Technologies is a high performance implementation of the SHA-1 Message Digest algorithm, a one-way hash function, compliant with FIPS 180-1. The core is composed of two main units, the SHA1 Engine and the Padding Unit.. The SHA1 Engine applies the SHA1 loops on a single 512-bit message block, while the Padding Unit splits the input message into 512-bit blocks and performs the message padding on the last block of the message