Normally buttress dams are made of concrete and feature a series braces called buttresses along the downstream side of the dam to prevent the natural flow of water. The Daniel-Johnson Dam in Quebec, Canada is a multiple arch buttress dam.
SHA-1 HMAC Generation. In cryptography, a keyed-hash message authentication code (HMAC) is a specific construction for calculating a message authentication code (MAC) involving a cryptographic hash function in combination with a secret cryptographic key.he following is a Python implementation of HMAC-MD5: Python includes an hmac module, so the function above can be replaced by a shorter version. The following is a PHP implementation of HMAC-SHA1: PHP includes an hmac function, so the example above can be replaced by a shorter version.
Originally, URAC was incorporated under the name Utilization Review Accreditation Commission.. However, that name was shortened to just the acronym URAC in 1996 when URAC began accrediting other types of organizations such as health plans and preferred provider organizations. This corporate name is sometimes used on URAC certificates and other written communications to help explain what URAC does.