Network Time Protocol Hardened To Protect Users From Spying, Increase Privacy (theregister.co.uk)

AmiMoJo quotes the Register: The Internet Engineering Task Force has taken another small step in protecting everybody's privacy... As the draft proposal explains, the RFCs that define NTP have what amounts to a convenience feature: packets going from client to server have the same set of fields as packets sent from servers to clients... "Populating these fields with accurate information is harmful to privacy of clients because it allows a passive observer to fingerprint clients and track them as they move across networks".

The header fields in question are Stratum, Root Delay, Root Dispersion, Reference ID, Reference Timestamp, Origin Timestamp, and Receive Timestamp. The Origin Timestamp and Receive Timestamp offer a handy example or a "particularly severe information leak". Under NTP's spec (RFC 5905), clients copy the server's most recent timestamp into their next request to a server – and that's a boon to a snoop-level watcher.
The proposal "proposes backward-compatible updates to the Network Time Protocol to strip unnecessary identifying information from client requests and to improve resilience against blind spoofing of unauthenticated server responses." Specifically, client developers should set those fields to zero.

Comments

I have since long given up on other peoples NTP.

[Anonymous Coward]

http://www.leobodnar.com/shop/...

Stratum1 FTW!

Local NTP is probably a bit more secure

[RevDisk]

I just use a GPS attachment. Well, GPS, GLONASS and Galileo. With a tiny bit of code to verify location checks out, math wise it'd be tricky to spoof. If my building moves by any significant amount, I'm fairly sure there's a problem of some sort that needs my attention. Spoofing the time and getting the locational data from all three providers to match would be kinda an impressive mathematical exercise. Plus, any domestic GPS spoofing will bring the anger of the FCC on someone and never underestimate interdepartment bureaucracy fury. It's kinda unlikely unless you're in a very high security environment.

Very simple to code. Cost me $50, and pretty much only because I wanted one that could handle multiple constellations. Or buy one off the shelf. More expensive, less work.

Re:Local NTP is probably a bit more secure

[RevDisk]

If the antenna position moves more than 10 feet, I have other concerns. ;)

Re:Perhaps a better solution

[Anonymous Coward]

But if everyone's garbage is different it's unique, and thus identifying, information.

Re:Why have a port open and listening all the time

[Zero__Kelvin]

Ignoring for the moment what a bad idea that would be, how do you plan on doing HTTP without a port open?

Re: When time.windows.com...

[Zero__Kelvin]

The hope that ignorant people will stop thinking Microsoft is competent? Double points for not thinking they must be competent because they are "big".