HMAC Authentication is short for Hash-Based Message Authentication Code, a strategy used to verify the integrity and authenticity of a message. This strategy is different from other authenticaton methods in the way that it used a cryptographic key along with a hash function. The algorithm behind the hashed message authentication code is complicated by hashing being performed twice. This helps in resisting forms of cryptographic analysis and protecting against threats. A hashed message authentication code is considered to be more secure than other similar message authentication codes, as the data transmitted and key used in the process are hashed separately.
Additional Reading: Detailing Veracode’s HMAC API Authentication