The AES-GCM128 core from Alma Technologies implements the GCM-AES authenticated encryption / decryption function, as specified in the NIST's SP800-38D recommendation for GCM and GMAC and the FIPS-197 Advanced Encryption Standard. The core can be programmed to either encrypt or decrypt 128-bit blocks of data with a 128-bit, 192-bit or 256-bit cipher key.