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.
From Wikipedia, the free encyclopedia. The Office of Foreign Assets Control (OFAC) is a financial intelligence and enforcement agency of the U.S. government charged with planning and execution of economic and trade sanctions in support of U.S. national security and foreign policy objectives.