In IT Security, a
ticket is a number generated by a network
server for a
client, which can be delivered to itself, or a different server as a means of
authentication or proof of
authorization, and cannot easily be forged. This usage of the word originated with
MIT's
Kerberos protocol in the 1980s. Tickets may either be
transparent, meaning they can be recognized without contacting the server that generated them; or
opaque, meaning the original server must be contacted to verify that it issued the ticket.