Subject: I-D Action: draft-stenn-ntp-not-you-refid-00.txt

From: [email-masked]
Date: Fri, 08 Jul 2016 03:53:24 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Network Time Protocol Not You REFID
        Authors         : Sharon Goldberg
                          Harlan Stenn
	Filename        : draft-stenn-ntp-not-you-refid-00.txt
	Pages           : 5
	Date            : 2016-07-08

Abstract:
   NTP has been widely used through several revisions, with the latest
   being RFC 5905 [RFC5905].  A core component of the protocol and the
   algoritms is the Reference ID, or REFID, which is used to identify
   the source of time used for synchronization (aka the "system peer").
   Traditionally, when the source of time was another system, the REFID
   was the IPv4 address of that other system.  The purpose of the REFID
   is to prevent a one-degree "timing loop": where if A has several
   timing sources that include B, if B decides to get its time from A,
   then A should not then decide to get its time from B.  The REFID is
   therefore a vital core-component of the base NTP packet.  If a
   system's REFID is the IPv4 address of its time source, then with a
   simple query a remote attacker can learn the target's REFID.  The
   remote attacker can then try to use that information to send spoofed
   NTP packets to the target or the target's time source, attempting to
   cause a disruption in time service [NDSS16].  Since the core purpose
   of the REFID is to prevent a one-degree timing loop, this proposal is
   a backward-compatible way to limit the amount of information that is
   leaked in the REFID.  Specifically, it allows the prevention of one-
   degree timing loops by allowing a system A to reveal to a querying
   system B that B is not A's time source, but without revealing the
   actual time source to which A is synchronized.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-stenn-ntp-not-you-refid/

There's also a htmlized version available at:
https://tools.ietf.org/html/draft-stenn-ntp-not-you-refid-00

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/