Alternative Approach for Mixing Preshared Keys in IKEv2 for Post-quantum Security
draft-smyslov-ipsecme-ikev2-qr-alt-01

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Network Working Group                                         V. Smyslov
Internet-Draft                                                ELVIS-PLUS
Intended status: Standards Track                        February 4, 2020
Expires: August 7, 2020

Alternative Approach for Mixing Preshared Keys in IKEv2 for Post-quantum
                                Security
                 draft-smyslov-ipsecme-ikev2-qr-alt-01

Abstract

   An IKEv2 extension defined in [I-D.ietf-ipsecme-qr-ikev2] allows
   IPsec traffic to be protected against someone storing VPN
   communications today and decrypting it later, when (and if) quantum
   computers are available.  However, this protection doesn't cover an
   initial IKEv2 SA, which might be unacceptable in some scenarios.
   This specification defines an alternative way get the same protection
   against quantum computers, which allows to extend it on the initial
   IKEv2 SA.

Status of This Memo

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   This Internet-Draft will expire on August 7, 2020.

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   Copyright (c) 2020 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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Smyslov                  Expires August 7, 2020                 [Page 1]
Internet-Draft          Alternative PPK for IKEv2          February 2020

   to this document.  Code Components extracted from this document must
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology and Notation  . . . . . . . . . . . . . . . . . .   3
   3.  Alternative Approach Description  . . . . . . . . . . . . . .   3
   4.  Computing IKE SA Keys . . . . . . . . . . . . . . . . . . . .   5
   5.  Comparison of the Conventional and the Alternative Approaches   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   The Internet Key Exchange Protocol version 2, defined in [RFC7296],
   is used in the IPsec architecture to perform authenticated key
   exchange.  [I-D.ietf-ipsecme-qr-ikev2] defines an extension of IKEv2
   for protecting today's VPN traffic against future quantum computers.
   At the time this extension was being developed, it was a consensus in
   the IPSECME WG that only IPsec traffic needs to have such a
   protection.  It was believed that no sensitive information is
   transferred over IKE SA and extending the protection to also cover
   IKE SA traffic would require serious modifications to core IKEv2
   protocol, that contradicted to one of the goals to minimize such
   changes.  For the cases when this protection is needed it was
   suggested to immediately rekey IKE SA once it is created.

   In some situations it is desirable to have this protection for IKE SA
   from the very beginning, when an initial IKE SA is created.  An
   example of such situation is Group Key Management protocol using
   IKEv2, defined in [I-D.yeung-g-ikev2].  In this protocol session keys
   are transferred from Group Controller / Key Server (GCKS) to Group
   Members (GM) immediately once an initial IKE SA is created.  While it
   is possible to postpone transfer of the keys until the IKE SA is
   rekeyed (and [I-D.yeung-g-ikev2] specifies how to do it), the needed
   sequence of actions introduces an additional delay and adds
   unnecessary complexity to the protocol.