MIKEY-IBAKE: Identity-Based Authenticated Key Exchange (IBAKE) Mode of Key Distribution in Multimedia Internet KEYing (MIKEY)
RFC 6267

Internet Engineering Task Force (IETF)                        V. Cakulev
Request for Comments: 6267                                   G. Sundaram
Category: Informational                                   Alcatel Lucent
ISSN: 2070-1721                                                June 2011

 MIKEY-IBAKE: Identity-Based Authenticated Key Exchange (IBAKE) Mode of
         Key Distribution in Multimedia Internet KEYing (MIKEY)

Abstract

   This document describes a key management protocol variant for the
   Multimedia Internet KEYing (MIKEY) protocol that relies on a trusted
   key management service.  In particular, this variant utilizes
   Identity-Based Authenticated Key Exchange (IBAKE) framework that
   allows the participating clients to perform mutual authentication and
   derive a session key in an asymmetric Identity-Based Encryption (IBE)
   framework.  This protocol, in addition to providing mutual
   authentication, eliminates the key escrow problem that is common in
   standard IBE and provides perfect forward and backward secrecy.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6267.

Copyright Notice

   Copyright (c) 2011 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
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   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must

Cakulev & Sundaram            Informational                     [Page 1]
RFC 6267                       MIKEY-IBAKE                     June 2011

   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
     2.1.  Requirements Language  . . . . . . . . . . . . . . . . . .  4
     2.2.  Definitions and Notation . . . . . . . . . . . . . . . . .  4
     2.3.  Abbreviations  . . . . . . . . . . . . . . . . . . . . . .  5
   3.  Use Case Scenarios . . . . . . . . . . . . . . . . . . . . . .  6
     3.1.  Forking  . . . . . . . . . . . . . . . . . . . . . . . . .  6
     3.2.  Retargeting  . . . . . . . . . . . . . . . . . . . . . . .  6
     3.3.  Deferred Delivery  . . . . . . . . . . . . . . . . . . . .  7
   4.  MIKEY-IBAKE Protocol Description . . . . . . . . . . . . . . .  7
     4.1.  Overview . . . . . . . . . . . . . . . . . . . . . . . . .  7
     4.2.  Message Exchanges and Processing . . . . . . . . . . . . . 10
       4.2.1.  REQUEST_KEY_INIT/REQUEST_KEY_RESP Message Exchange . . 10
       4.2.2.  I_MESSAGE/R_MESSAGE Message Exchanges  . . . . . . . . 12
   5.  Key Management . . . . . . . . . . . . . . . . . . . . . . . . 16
     5.1.  Generating Keys from the Session Key . . . . . . . . . . . 17
     5.2.  Generating Keys for MIKEY Messages . . . . . . . . . . . . 17
     5.3.  CSB Update . . . . . . . . . . . . . . . . . . . . . . . . 18
     5.4.  Generating MAC and Verification Message  . . . . . . . . . 18
   6.  Payload Encoding . . . . . . . . . . . . . . . . . . . . . . . 19
     6.1.  Common Header Payload (HDR)  . . . . . . . . . . . . . . . 19
       6.1.1.  IBAKE Payload  . . . . . . . . . . . . . . . . . . . . 20
       6.1.2.  Encrypted Secret Key (ESK) Payload . . . . . . . . . . 21
       6.1.3.  Key Data Sub-Payload . . . . . . . . . . . . . . . . . 21
       6.1.4.  EC Diffie-Hellman Sub-Payload  . . . . . . . . . . . . 22
       6.1.5.  Secret Key Sub-Payload . . . . . . . . . . . . . . . . 23
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 24
     7.1.  General Security Considerations  . . . . . . . . . . . . . 24
     7.2.  IBAKE Protocol Security Considerations . . . . . . . . . . 25
     7.3.  Forking  . . . . . . . . . . . . . . . . . . . . . . . . . 26
     7.4.  Retargeting  . . . . . . . . . . . . . . . . . . . . . . . 26