PRACTICE - ACCESS Control

• Cognative password - user asked several questions - don't
• need to remember one password

Virtual Password is the length and format that is required by the application. could be used as the key in an algorithm

• more diverse centralized access control administration than RADIUS and TACAS+
• supports PPPP, sLIP ...

• Kerberos - user enters credentials and obtains a TGT
• timestamp that makes it valid for 8 hours

• Kerberos client sends the TGT to the TGS which creates a second ticket.
• His ticket is used by the user to authenticate to the network resource

Kerberos - users sends authentication information to Authentication Service (AS)

AS creates a ticket granting ticket (TGT). which is encrypted with the user's secret key.

The TGT is used to communicate to THE ticket granting service (TGS)

TGS creates a ticket that contains two instances of the same session key that is encrypted with the individual principal's secret keys.

It is the second ticket that allows the 2 principals to obtain their session keys

• Synchronous token device - driven by time or events to authenticate users
• asynchronous token device uses a challenge-based mechanismduring authentication

Salt - random value that is added during enryptinog process on non-windows systems.