1. Wireless Access Points
Authentication and Association Methods

2. Two Step Process
Authentication
Association

3. The A & A Process
“I’d like to authenticate”

4. The A & A Process
“I’d like to authenticate”
“Authentication granted”

5. The A & A Process “I’d like to authenticate” “Authentication granted”
“I’d like to associate”

6. The A & A Process “I’d like to authenticate” “Authentication granted”
“I’d like to associate”
“Association granted”

7. Authentication Methods
Open System
Shared Key
802.1x and EAP
Now, let’s look at each of these...

8. Open System Authentication
“I’d like to authenticate”
“Authentication granted”
Also called “null authentication.”
Authentication is granted to every request.
No challenge is issued.
Can be used with or without encryption (encryption, if used, will be applied during association).

9. Shared Key Authentication
“I’d like to authenticate”
Station and WAP both have the shared key

10. Shared Key Authentication
“I’d like to authenticate”
“Encrypt this: ‘abcd123’”
WAP sends the challenge

11. Shared Key Authentication
“I’d like to authenticate”
“Encrypt this: ‘abcd123’”
“Here it is: ‘yg48cr%w’”
Station response:
encrypts the challenge with the shared key

12. Shared Key Authentication
“I’d like to authenticate”
“Encrypt this: ‘abcd123’”
“Here it is: yg48cr%w”
“Authentication granted”
WAP decrypts the response and, if correct, authenticates the Station

13. Shared Key Authentication
“I’d like to authenticate”
“Encrypt this: ‘abcd123’”
“Here it is: yg48cr%w”
“Authentication granted”
“I’d like to associate”

14. Shared Key Authentication
“I’d like to authenticate”
“Encrypt this: ‘abcd123’”
“Here it is: yg48cr%w”
“Authentication granted”
“I’d like to associate”
“Association granted”

15. 802.1x and EAP Authentication
Auth. Request
RADIUS Server
EAP Identity Request
EAP Identity Response
EAP Identity Response
RADIUS Access Challenge
RADIUS Access Challenge
RADIUS Challenge Response
RADIUS Challenge Response
EAP Success Response
EAP Success Response
“I’d like to associate.”
“Association granted.”

16. This is the end.