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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.
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.
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Stratum1 FTW!
I assume you mean because GPS is run by government? Meh. as long as governments (mulitple) are using the same time source I actually trust it quite a bit. Besides, atomic clocks essentially mean trusting government too... they are ALL either directly or indirectly funded by governments, even one you buy yourself for personal use.
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.
Fill the fields with plausible garbage. If the data has no legitimate usage, poison it.
Wowsers that's a lot of money. You can get PPS out of neo8m
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Anytime anybody says they are doing something "to protect you from spying" or to "increase your privacy" You would do well to watch very closely and try to read between the lines. Sometimes your just a paranoid nutcase. Sometimes.
You are being ripped off every second of every day, so that advertisers can help rip you off even more tomorrow.
HTTPS over UDP
Slashdot, fix the reply notifications... You won't get away with it...
can't even get the time correct, we should be focusing on reliability instead of security.
That's a normal behavior. Windows has always been a few years behind.
Slashdot, fix the reply notifications... You won't get away with it...
Nice, but pretty pricey. Not quite in the league of a Symmetricom privewise, but getting close. I'm running more or less the same thing but without the OLED display at 1/10th the price. Unfortunately the guy who made them on Tindie seems to have gone away, so I can't provide a link.
Check your protocols.
Actually, establishing (and tearing down) an encrypted TCP channel is far less simple than UDP based ntp.
The open port isn't a requirement, but it is how ntp does the important (and complicated) part - establishing what the real time actually is, without blind faith in just one other server.
OTP (Office Time Protocol) predates even that one by decades, and is probably more accurate than Microsoft's NTP:
Hey Jim, what time is it?
About five-ish
Beer o'clock?
Yeah, about that.
Never failed so far.
Ignoring for the moment what a bad idea that would be, how do you plan on doing HTTP without a port open?
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
The hope that ignorant people will stop thinking Microsoft is competent? Double points for not thinking they must be competent because they are "big".
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
It's not just that, in a domain you've actually got CTP, Clusterfuck Time Protocol. Let's see, we'll all sync to that backup domain controller over there, which is sync'd to another BDC, one of which syncs to the PDC, which in turn syncs to a different BDC. Having that lot settling on a time is like watching a bunch of rednecks debate how gravity waves work, they eventually converge on some sort of solution but it sure ain't the solution that anyone else is on.
Linux doesn't need "real time extensions". Linux has had soft realtime support in the mainline kernel for a frigging decade. Furthermore, clock drift is "a thing" everywhere. If it were not then there would be no need for NTP.
You don't seem to understand that IOS is Linux based.
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
It's amusing that you think being real-time has anything to do with keeping time.
IP over Avian Carriers
The government could turn off the NIST atomic clock, but couldn't turn off the ones in universities or the like. GPS is explicitly run by the US government, and has been tweaked to reduce its efficiency.
Learn to love Alaska
My stratum 1 server also receives timing from the Russian glonass constellation. American GPS is not the only game in town, and hasn't been for many years.
Kid-proof tablet..