On Tue, Sep 27, 2016 at 09:13:30PM -0000, johnyju...@sigaint.org wrote: > > My PC's RT clock might drift by a few seconds each week > > Actually, it's not even that bad. I'm sure I've fired up motherboards or > laptops that haven't been touched in years, and their clocks were accurate > within a minute. > > So there's no need for synchronizing your time so frequently. > > I just read that NTP apparently adjust the frequency of polling based upon > how fast your clock seems to be drifting, which is admirable. > > http://www.ntp.org/ntpfaq/NTP-s-algo.htm > > But the poll interface ranges from 64 to 1024 seconds; even at the high > end, that seems unnecessarily frequent from the very small amount of clock > drift I've experienced. > > But flipping to a GPS-based source instantly eliminates those concerns. > > Question: for what purpose do we require super-accurate clocks in the > first place? There are some rolling password algorithms based upon time, > and certificates handling will get cranky if you're months or years off, > but other than that, what is the necessity of keeping a PC within seconds > of the correct time? > > (On tails, when it starts up, it does a time synchronization, claiming > it's required for Tor purposes. Anyone know the nature of that?) > > JJ >
Like many encrypted tunnel setups, Tor requires both ends to have similar date/time. You can easily test this by manually setting to the wrong time, and watching the Tor fail. Tor also checks your local date/time against the consensus status document, and will warn you if it's off. If it's too far, you won't get tunnels. Connecting to Hidden services , I think, requires that local date/time be within 60 mins of the service provider. Tails has a mechanism to set local time. Whonix has a similar mechanism, also available in Whonix-Qubes. unman -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/20160927215839.GB5446%40thirdeyesecurity.org. For more options, visit https://groups.google.com/d/optout.