Network Time Protocol: autokey Version 2 Specification
draft-sibold-autokey-01

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NTP Working Group                                              D. Sibold
Internet-Draft                                                       PTB
Intended status: Standards Track                             S. Roettger
Expires: August 01, 2013                                           TU-BS
                                                        January 30, 2013

         Network Time Protocol: autokey Version 2 Specification
                        draft-sibold-autokey-01

Abstract

   This document describes a security protocol that enables
   authenticated time synchronization using Network Time Protocol (NTP).
   Autokey Version 2 obsoletes NTP autokey protocol RFC 5906 [RFC5906]
   which suffers from various security vulnerabilities.  Its design
   considers the special requirements that are related to the task of
   precise timekeeping.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on August 01, 2013.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Internet-Draft               NTP autokey V2                 January 2013

   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 carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must 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 . . . . . . . . . . . . . . . . . . . . . . . . .  2
     1.1.  Differences from the original autokey  . . . . . . . . . .  3
   2.  Security Threats . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Objectives . . . . . . . . . . . . . . . . . . . . . . . . . .  3
   4.  Terms and abbreviations  . . . . . . . . . . . . . . . . . . .  4
   5.  Autokey Overview . . . . . . . . . . . . . . . . . . . . . . .  4
   6.  Protocol Sequence  . . . . . . . . . . . . . . . . . . . . . .  4
     6.1.  Association Message  . . . . . . . . . . . . . . . . . . .  4
     6.2.  Certificate Message  . . . . . . . . . . . . . . . . . . .  4
     6.3.  Cookie Message . . . . . . . . . . . . . . . . . . . . . .  5
     6.4.  Time Request Message . . . . . . . . . . . . . . . . . . .  5
   7.  Hash algorithms and MAC generation . . . . . . . . . . . . . .  5
     7.1.  Hash algorithms  . . . . . . . . . . . . . . . . . . . . .  5
     7.2.  MAC Calculation  . . . . . . . . . . . . . . . . . . . . .  6
   8.  Server Seed Considerations . . . . . . . . . . . . . . . . . .  6
     8.1.  Server Seed algorithm  . . . . . . . . . . . . . . . . . .  6
     8.2.  Server Seed Live Time  . . . . . . . . . . . . . . . . . .  6
   9.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  6
   10. Security Considerations  . . . . . . . . . . . . . . . . . . .  6
   11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  6
   12. References . . . . . . . . . . . . . . . . . . . . . . . . . .  6
     12.1.  Normative References  . . . . . . . . . . . . . . . . . .  7
     12.2.  Informative References  . . . . . . . . . . . . . . . . .  7
   Appendix A. TICTOC Security Requirements . . . . . . . . . . . . .  7
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .  8

1.  Introduction

   In NTP [RFC5905] the autokey protocol [RFC5906] was introduced to
   provide authenticity to NTP servers and to ensure integrity of time
   synchronization.  It is designed to meet the specific communication
   requirements of precise timekeeping and therefore does not compromise
   timekeeping precision.

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