Opened 5 years ago

Closed 5 years ago

Last modified 3 years ago

#13193 closed enhancement (implemented)

Tag circuits locally by exit vs hidden-service, for stats

Reported by: arma Owned by:
Priority: Medium Milestone:
Component: Core Tor/Tor Version:
Severity: Keywords: tor-relay
Cc: Actual Points:
Parent ID: #13192 Points:
Reviewer: Sponsor: SponsorR

Description

If we as a relay see a begin cell on a circuit, we know it's for exiting.

And if we see one of the various hidden service related cells on it, we know it's for hidden services.

And if we see an extend cell, we're a middle (i.e intermediary) hop in a circuit that terminates somewhere else. (assuming nobody uses the leaky pipe topology design, where you can exit from intermediary hops).

How many of each type of circuit do relays of various types handle?

And finally, what privacy risks are there to publishing aggregate ("total over past n seconds") statistics? for various values of n?

One approach to ameliorating the privacy question could be to discard circuits where the previous hop isn't a known relay. I think that's relays in the guard position, and relays in the middle-hop position for users who use bridges.

Child Tickets

Change History (9)

comment:1 Changed 5 years ago by cypherpunks

If this and other similar stuff like crawling is indeed going to be done whether we like it or not, it should not be in release versions of Tor.

comment:2 Changed 5 years ago by cypherpunks

Who's Sponsor R?

comment:3 in reply to:  1 Changed 5 years ago by arma

Replying to cypherpunks:

If this and other similar stuff like crawling is indeed going to be done whether we like it or not, it should not be in release versions of Tor.

Well, the goal here is to get a sense of what Tor is actually used for, to help us understand how to focus our development energy. Think of it like profiling. With the additional challenge of course that, like everything else to do with Tor, there are privacy questions to answer too.

As for whether to put it in release versions of Tor, I think step one is to get some simple code that measures some stuff, and then see if it works, and then see if we think getting those numbers from more relays would be useful and not harmful. A lot of the interesting profiling work will come from changes in trends over time, not from grabbing one number on a Sunday in September. For example, it sure would have been useful to have some hidden-service related broad network statistics when the botnet showed up in August 2013 -- and we still have no idea whether those bots are loading down the network right now or not.

I do have hopes of eventually, once we've gotten everything the way we want it, adding some global statistics to the extra-info descriptor, to go with all the other statistics we already collect at relays.

comment:4 in reply to:  2 Changed 5 years ago by arma

Replying to cypherpunks:

Who's Sponsor R?

Some of our sponsors want anonymity, so we try not to explicitly deanonymize any of them. But this one doesn't particularly want anonymity, so I expect we'll do some sort of announcement pretty soon.

But the other answer is, if you're asking "wait, they want anonymity? what do they have to hide?" then you're doing it wrong. :) That's why we post all the tickets and details of what we're doing on the wiki.

comment:5 in reply to:  description Changed 5 years ago by arma

Replying to arma:

How many of each type of circuit do relays of various types handle?

My hs-stats branch now collects these answers, and logs a summary once per minute. Once we know it's working, we should raise the "once per minute" period to something much larger.

Also, I'd like to look at logging the number of relay cells we handle for each type, so we can start to answer "how much of Tor's traffic is hidden service related?"

comment:6 Changed 5 years ago by arma

Resolution: implemented
Status: newclosed

Ok, this is implemented in my hs-stats branch. I'm going to close this one since the tagging works -- but the parent topic remains open.

comment:7 Changed 4 years ago by dgoulet

Keywords: SponsorR removed
Sponsor: SponsorR

comment:8 Changed 3 years ago by teor

Milestone: Tor: 0.2.???Tor: 0.3.???

Milestone renamed

comment:9 Changed 3 years ago by nickm

Milestone: Tor: 0.3.???

Milestone deleted

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