what is Authenticate ?

Authenticate—To verify the identity of a user, user device, or other entity, or the integrity of data stored,
transmitted, or otherwise exposed to possible unauthorized modification in an automated
information system, or establish the validity of a transmitted message.
Authenticated identity—An identity of a principal that has been assured through authentication.
Authentication—The act of identifying or verifying the eligibility of a station, originator, or individual to
access specific categories of information. Typically, a measure designed to protect against
fraudulent transmissions by establishing the validity of a transmission, message, station, or
Authentication certificate—Authentication information in the form of a security certificate which may
be used to assure the identity of an entity guaranteed by an authentication authority.
Authentication exchange—A sequence of one or more transfers of exchange authentication information
(AI) for the purposes of performing an authentication.
Authentication header—An IPsec protocol that provides data origin authentication, packet integrity, and
limited protection from replay attacks.
Authentication Information (AI)—Information used to establish the validity of a claimed identity.
Authentication initiator—The entity which starts an authentication exchange.
Authentication method—Method for demonstrating knowledge of a secret. The quality of the
authentication method, its strength is determined by the cryptographic basis of the key
Architecture for Public-Key Infrastructure (APKI) Draft distribution service on which it is based.
A symmetric key based method, in which both entities share common authentication information,
is considered to be a weaker method than an asymmetric key based method, in which not all the
authentication information is shared by both entities.
Authenticity—(1) The ability to ensure that the information originates or is endorsed from the source
which is attributed to that information. (2) The service that ensures that system events are
initiated by and traceable to authorized entities. It is composed of authentication and