1. EAP Password Authenticated eXchange (PAX)
draft-clancy-eap-pax-02
T. Charles Clancy William A. Arbaugh
Department of Computer Science
University of Maryland, College Park
IETF 62, EAP WG
March 10, 2005

2. PAX Overview / Features
Simple shared-key mutual authentication
Extended mode supports provisioning and identity protection
Supports key management with forward secrecy using Diffie-Hellman
Extensible ciphersuite

3. Changes Since -01
Consolidated PAX_STD with certificate and PAX_IDP into the 3RT PAX_SEC
supports provisioning
supports identity protection
PAX_SEC requires public key, but not certificate
removed server-side NAI from protocol/hashes

4. PAX_STD X,Y = rand(2256) If keyUpdate then A = gX, B = gY, E = gXY
else A = X, B = Y, E = (X || Y)
{AK’, CK, SessionKeys} = PRF(AK || E || KeyName)
Client
Server A
B, CID, MACCK(A, B, CID)
MACCK(B, CID)
ACK

5. PAX_SEC (secure mode) Client Server M, PK, [CertPK] EncPK (M, N, CID)
A, MACN(A, CID)
B, MACCK(A, B, CID)
MACCK(B, CID)
ACK

6. Desired EAP-PAX Future
standards-track draft
EAP WG document
to accomplish:
EAP WG charter needs to be amended
suggest charter work item:
“10. standardization of EAP methods”