[tor-dev] A Simple Web of Trust for Tor Relay Operator IDs

yanmaani at cock.li yanmaani at cock.li
Sun Oct 24 05:37:27 UTC 2021

(sorry for replying directly before)
On 2021-10-03 16:16, nusenu-lists at riseup.net wrote:
> Hi,
> I wrote down a spec for a simple web of trust
> for relay operator IDs:

Some comments, in no particular order:

Why not just put the keys in directly, or even a magnet link to your 
latest web of trust? That would remove the need to trust SSL CAs.

What problems does this solve, specifically, and how? If I - me 
personally, not the generic I - wanted to spin up a relay, how would I 
do that?

Would I go on this mailing list and ask random people to sign my relay? 
If so, it's not very useful.

Or would I just run it without any signatures at all? If so, it's not 
very useful.

The basic problem, I think, is the same as for PGP: it's not really 
clear what you're attesting to when you sign. If I sign a my mate's 
relay, and then that relay turns out to be dodgy, do I also lose my 
relay operation privileges?

I think that WoT systems have a definite value for preventing Sybil 
attacks, they are very powerful, and I don't think these issues are 
insurmountable, but they have to be addressed.

If you're going to do it in a "machine-friendly" manner, then I suppose 
you have to come up with some kind of formalized notion of what trust 
represents, maybe have some numerical scale so you can define (just as 
an example) 100 = "I've personally audited the hardware", 70 = "This is 
an organization I trust", 10 = "I know who this person is, it's not just 
a fresh hotmail".

Or, you can do it in a "human-friendly" manner, where you just write 
text notes with each trust relationship. That would make it quite 
useless to parse, but could be useful to give us some information about 

Now, here's my gut feeling:

Instinctively, it seems silly to have the trust relationships denote 
"this person is a good relay operator" (how would you even quantify 
that?), and maybe more reasonable to have it denote "I know this guy, he 
didn't just pop into existence last Thursday". And if you're doing that, 
it seems like the second approach makes more sense. This clearly 
suggests some limitations to it, but possibly still useful.

Anyway, if you're going to do that, it might also be reasonable to hook 
into a pre-existing web of trust, like GPG or something. That way, we 
can encode stuff like "I trust my mate Alice, she isn't a relay 
operator, she trusts Bob, who is, therefore I transitively trust Bob." 
This doesn't work great if Alice has to register in the separate Tor Web 
of Trust thing. (On the other hand, we introduce the problem of someone 
doing a Sybil by being introduced to random people who will sign 
literally anything, not being aware of Tor, and then showing up with 
plausible-looking trust pairs. But maybe that's not such a big problem, 
because that arguably looks even shadier?)

I think this is a very good initiative, anyway.

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