Message Authentication Code for the Network Time Protocol

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: The IESG <>,,, Karen O'Donoghue <>,,,,
Subject: Protocol Action: 'Message Authentication Code for the Network Time Protocol' to Proposed Standard (draft-ietf-ntp-mac-06.txt)

The IESG has approved the following document:
- 'Message Authentication Code for the Network Time Protocol'
  (draft-ietf-ntp-mac-06.txt) as Proposed Standard

This document is the product of the Network Time Protocol Working Group.

The IESG contact persons are Suresh Krishnan and Terry Manderson.

A URL of this Internet Draft is:

Technical Summary

RFC 5905 [RFC5905] states that Network Time Protocol (NTP) packets  should be authenticated by appending a 128-bit key to the NTP data, and hashing the result with MD5 to obtain a 128-bit tag.  This document deprecates MD5-based authentication, which is considered to be too weak, and recommends the use of AES-CMAC [RFC4493] as a replacement. 

Working Group Summary

The document has clear working group consensus for publication, and has been reviewed by several WG participants since its initial adoption as a working group item. 

Document Quality

This document has been reviewed and revised several times during its development. There were no specific external expert reviews conducted. 


Karen O'Donoghue is acting as the Document Shepherd.  Suresh Krishnan is the Responsible Area Director.