Jessica Tallon's implementation of petnames and edge names was extremely simple within the paper davexunit linked, but used in-band mechanisms to communicate edge names that didn't require any sort of large trusted authority. You could retrieve them directly from fellow peers, who could publish their current set of edge names. This even works in a p2p context over ocapn, etc. The implementation was naive but it did work and used a publish-subscribe mechanism directly from other peers.

That said, edge names are only one way to share contacts. In fact "share contact" on peoples' phones is a great way to have contextual sharing: "Oh, let me introduce you to my friend Dave. Here's Dave's contact info!"

At any rate, petnames aren't a particular technology, they're a design space of "Secure UI/UX". However I do agree more research needs to be done in that space; we've only barely begun to scratch the surface.

is not this WoT just about "i fully trust Dr A's public key is P1 because he gave it to me personally. i trust Dr A's sibling's public key is P2 because i've found it somewhere and it's cryptographically signed with P1. so i'm highly confident that this cryptographically signed message is from Dr A's sibling as long as neither P1 or P2 compromised or misused in the meanwhile." ?

> Not inherently: for all I know, my doctor is technically illiterate and their contact book is thoroughly padded with spam.

Sure, but that leads us to the next question: Could it provide you utility?

> The problem of trust is that trust isn't a boolean

That's also the utility of trust. Most of the information we want to reason about is not context-free. So far, no one has figured out a reliable way to offload context-sensitive work to computation. The next best thing is to offload as much context-free work as possible, and provide the user a direct interface to the remaining context-sensitive work.

By organizing our social networks as attestations of [dis]trust, we can deliver the uncomputable question of trustworthiness closer to the user. By delivering that question to many users, we can collaborate efficiently on that work.

So you can trust friend of a friend only after awaiting him (with apologies to https://journal.stuffwithstuff.com/2015/02/01/what-color-is-...)?

100% agree about the difference in meaning between the two uses of “trust”. To be frank I responded after only skimming over your comment, and should have read a bit more closely. FWIW, I think there’s a way to unify those two realms: if you model boolean trust in terms of a random variable and sum over the transitive web à la binomial distribution.

There’s also a compounding effect. If multiple friends vouch for the same stranger that means something too.