authentication means mainly fraud protection.

identifier+claim=authentication.
authentication is the process of establishing a level of confidence regarding a claim.
authentication is the act of confirming that aspecific thing is true.In the computer field it is used by registering with a user name anbd password which is secret to the user.so perticular personcan can be identified and authenticated via the password.autherisation provides after authentiction.

the required participants for authentication;
1.presenter
2.verifier
3.issuer
risks associated with authentication:
man in the iddle attack
errors
theft
fraud
population
allocation
the historical context of authentication and identity:
membership
religion
military
financial
authntication methods :
passwords:- In this user generated,system generated,passphases.
query directional passwords:-
1.knowledge based
2.personal data
3.shared secrets.
QDP specifications:

1.answer should be consistently and easily recallable by a usre one time
2.answer should be discriminating of user
3.answer should be easily gussed or learnned
4.aswer should be independent of each other
5.questions offered for usre selection should be fairly large no.

Multifactor authentication decreases the risk of one or ore methods being compromised.
graphical authentication:
congnometic,
locimetic,
draw etric