Describe the use and purpose of hashes and digital signatures in providing message authentication and integrity. Review these resources on authentication to further your understanding. Focus on resources pertaining to message authentication.
a. Authentication is the process by which credentials are presented and validated to enable access. There are a number of different methods of authentication. Passwords are the most common type of authentication and are usually coupled with user identification (user IDs). Tokens and certificates are often used in place of passwords to provide a higher level of security. Tokens can contain unique identifiers (e.g., digital signatures or keys). Tokens can also store biometric data—for example, fingerprints.