the process of establishing the authenticity of a person or other entity. Not to be confused with authorization - defining access rights to resources.
Authentication: establishing the authenticity of a person or other entity. Abbreviated "authn". Not to be confused with defining access rights to resources, which is the topic of authorization (authz)
See more at http://en.wikipedia.org/wiki/Authentication
An update on the state of the art and a research agenda is in the IEEE Security and Privacy Magazine special issue for January/February 2012: Authentication—Are We Doing Well Enough?
