Answer:
Hash.
Explanation:
An authentication can be defined as the process of verifying the identity of an individual or electronic device. Authentication work based on the principle (framework) of matching an incoming request from a user or electronic device to a set of uniquely defined credentials.
Basically, authentication ensures a user is truly who he or she claims to be, as well as confirm that an electronic device is valid through the process of verification. Smart cards, digital certificates, picture passwords, and biometrics are generally used to perform an authentication in the field of computer.
Hence, when authenticating a user's password, the password supplied by the user is authenticated by comparing the hash of the password with the one stored on the system.
In Computer science, a hash function can be defined as any function which is used to map data by accepting a block of data with variable length size or arbitrary size as input to produce a fixed size hash values or codes.
Generally, when a block of data (input) of arbitrary size is hashed, the resulting hash values or codes is usually smaller than the input data. Thus, hash functions are considered to be a compression of data and as a result, sometimes called compression functions. Basically, the block size of a hash function typically ranges from 128 bits to 512 bits.