Augmented Password-Authenticated Key Exchange (AugPAKE)
draft-irtf-cfrg-augpake-08

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Last updated 2017-07-18
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Internet Research Task Force                                   S.H. Shin
Internet-Draft                                                 K. Kobara
Intended status: Informational                                      AIST
Expires: January 20, 2018                                  July 19, 2017

        Augmented Password-Authenticated Key Exchange (AugPAKE)
                       draft-irtf-cfrg-augpake-08

Abstract

   This document describes a secure and highly-efficient augmented
   password-authenticated key exchange (AugPAKE) protocol where a user
   remembers a low-entropy password and its verifier is registered in
   the intended server.  In general, the user's password is chosen from
   a small set of dictionary, making the password susceptible to offline
   dictionary attacks.  The AugPAKE protocol described here is secure
   against passive attacks, active attacks and offline dictionary
   attacks (on the obtained messages with passive/active attacks).
   Also, this protocol provides resistance to server compromise in the
   context that an attacker, who obtained the password verifier from the
   server, must at least perform offline dictionary attacks to gain any
   advantage in impersonating the user.  The AugPAKE protocol is not
   only provably secure in the random oracle model but also the most
   efficient over the previous augmented PAKE protocols (SRP and AMP).

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on January 20, 2018.

Shin & Kobara           Expires January 20, 2018                [Page 1]
Internet-Draft          Augmented PAKE (AugPAKE)               July 2017

Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Keywords  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  AugPAKE Specification . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Underlying Group  . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Notation  . . . . . . . . . . . . . . . . . . . . . . . .   4
       2.2.1.  Password Processing . . . . . . . . . . . . . . . . .   6
     2.3.  Protocol  . . . . . . . . . . . . . . . . . . . . . . . .   6
       2.3.1.  Initialization  . . . . . . . . . . . . . . . . . . .   7
       2.3.2.  Actual Protocol Execution . . . . . . . . . . . . . .   7
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
     3.1.  General Assumptions . . . . . . . . . . . . . . . . . . .   9
     3.2.  Security against Passive Attacks  . . . . . . . . . . . .   9
     3.3.  Security against Active Attacks . . . . . . . . . . . . .  10
       3.3.1.  Impersonation Attacks on User U . . . . . . . . . . .  10
       3.3.2.  Impersonation Attacks on Server S . . . . . . . . . .  10
       3.3.3.  Man-in-the-Middle Attacks . . . . . . . . . . . . . .  11
     3.4.  Security against Off-line Dictionary Attacks  . . . . . .  11
     3.5.  Resistance to Server Compromise . . . . . . . . . . . . .  12
   4.  Implementation Consideration  . . . . . . . . . . . . . . . .  13
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Appendix A.  Features of AugPAKE  . . . . . . . . . . . . . . . .  15
   Appendix B.  Test Vector of AugPAKE . . . . . . . . . . . . . . .  16
   Appendix C.  AugPAKE over EC Groups . . . . . . . . . . . . . . .  18
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