Network Time Security
draft-ietf-ntp-network-time-security-11
NTP Working Group D. Sibold
Internet-Draft PTB
Intended status: Standards Track S. Roettger
Expires: April 21, 2016 Google Inc.
K. Teichel
PTB
October 19, 2015
Network Time Security
draft-ietf-ntp-network-time-security-11
Abstract
This document describes Network Time Security (NTS), a collection of
measures that enable secure time synchronization with time servers
using protocols like the Network Time Protocol (NTP) or the Precision
Time Protocol (PTP). Its design considers the special requirements
of precise timekeeping which are described in Security Requirements
of Time Protocols in Packet Switched Networks [RFC7384].
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
working documents as Internet-Drafts. The list of current Internet-
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 April 21, 2016.
Sibold, et al. Expires April 21, 2016 [Page 1]
Internet-Draft NTS October 2015
Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Terms and Abbreviations . . . . . . . . . . . . . . . . . 4
2.2. Common Terminology for PTP and NTP . . . . . . . . . . . 4
3. Security Threats . . . . . . . . . . . . . . . . . . . . . . 5
4. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. NTS Overview . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Protocol Messages . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Unicast Time Synchronisation Messages . . . . . . . . . . 7
6.1.1. Preconditions for the Unicast Time Synchronization
Exchange . . . . . . . . . . . . . . . . . . . . . . 7
6.1.2. Goals of the Unicast Time Synchronization Exchange . 8
6.1.3. Message Type: "time_request" . . . . . . . . . . . . 8
6.1.4. Message Type: "time_response" . . . . . . . . . . . . 8
6.1.5. Procedure Overview of the Unicast Time
Synchronization Exchange . . . . . . . . . . . . . . 9
6.2. Broadcast Time Synchronization Exchange . . . . . . . . . 10
6.2.1. Preconditions for the Broadcast Time Synchronization
Exchange . . . . . . . . . . . . . . . . . . . . . . 10
6.2.2. Goals of the Broadcast Time Synchronization Exchange 11
6.2.3. Message Type: "server_broad" . . . . . . . . . . . . 11
6.2.4. Procedure Overview of Broadcast Time Synchronization
Exchange . . . . . . . . . . . . . . . . . . . . . . 11
6.3. Broadcast Keycheck . . . . . . . . . . . . . . . . . . . 13
6.3.1. Preconditions for the Broadcast Keycheck Exchange . . 13
6.3.2. Goals of the Broadcast Keycheck Exchange . . . . . . 13
6.3.3. Message Type: "client_keycheck" . . . . . . . . . . . 14
6.3.4. Message Type: "server_keycheck" . . . . . . . . . . . 14
6.3.5. Procedure Overview of the Broadcast Keycheck Exchange 14
7. Server Seed Considerations . . . . . . . . . . . . . . . . . 16
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