Wimax standards and Security The Wimax

Appendix II: EAP
Extensible authentication protocol is a general authentication protocol sup- porting multiple authentication methods such as token cards, Kerberos, one-time passwords, certificates, public key authentication, and smart cards. EAP is an authentication framework providing some common functions. It typically runs directly over data link layers such as point-to-point proto- col (PPP) or IEEE 802, without requiring IP. EAP provides its own support for duplicate elimination and retransmission but is reliant on lower-layer ordering guarantees.
In the WiMAX mode using EAP, the SS sends connection request to the BS with its identity, and the BS transmits that identity to an authentication server. Both the server and the SS derive a session key. The BS gets the session key from the SS and then sends back to the server to complete the authentication.





Appendix III: RSA
RSA, named after its inventors, Ron Rivest, Adi Shamir, and Leonard Adleman, is a public-key encryption algorithm. RSA uses the private key and the public key to lock or unlock a message, respectively. The receiver sends its public key to the sender. Then the sender sends out the message encrypted

with this public key. After receiving the message, the receiver decrypts the message using the private key.

The RSA algorithm consists of the following steps:

• 
  Select two different large prime numbers p and q.
  
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  Compute n = p ∗ q.
  
• 
  
  — ∗ −
  
  — ∗ −
  Select a small, odd integer e < (p 1) (q 1); the numbers e and (p 1) (q 1) must be relatively prime, i.e., they should not share common prime factors.
  
• 
  Compute d, where d ∗ e mod ((p − 1) ∗ (q − 1)) = 1.
  
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  The ordered pair (e, n) is the RSA public key.
  
• 
  The ordered pair (d, n) is the RSA private key.
  

For example, given a message “M,’’ its encrypted form is the binary message “Z.’’
Z = (M^e) mod n.
Inversely, decrypt the message “Z’’ by


M = (Z^d) mod n.