
The process of linking credentials provided by an individual or system to an identity for the purpose of granting access to a system. Credentials can take various forms –passwords or other ‘shared secrets’, certificates or other key pairs, and tokens are the most common forms. Credentials have different strengths and costs: passwords are inexpensive to set up but are subject to many different attacks (guessing; intercepting); certificates and key pairs are more resource intensive to generate and verify, but are more secure; tokens are more expensive to purchase and verify, but are simpler to use and secure.