[wtbob]

> Can you think of anything easier?

I think signal:wtbob works just as well as tel:[phone], if we want to continue to rely on OWS as a central identity provider.

I think that 'mom's dad's sister June' also works, if we want decentralised identity.

[privong]

> I think signal:wtbob works just as well as tel:[phone]

That doesn't work as well for auto-discovery of other Signal users, though. The latter enables auto-discovery based on people whose phone numbers are already in one's contact books. With the former, one needs to collect other people's usernames. It's not a tough thing to do, but it does make auto-discovery difficult.

[zeveb]

> That doesn't work as well for auto-discovery of other Signal users, though.

It does if one's Contacts app stores Signal contact information for one's contacts; then one could simply query using non-Signal information as the key (e.g. one could ask, 'give me Signal contact information for tel:[phone], mailto:[e-mail] and http://plus.google.com/SomeUserName').

[privong]

> one could simply query using non-Signal information as the key (e.g. one could ask, 'give me Signal contact information for tel:[phone], mailto:[e-mail] and http://plus.google.com/SomeUserName').

That doesn't seem like a very good tradeoff because then it requires Signal to store/compare _more_ personally identifying information (though I guess you could make many of those things pseudo-anonymous).

[wtbob]

> That doesn't seem like a very good tradeoff because then it requires Signal to store/compare _more_ personally identifying information (though I guess you could make many of those things pseudo-anonymous).

Actually, it's possible to do even better that that: one can execute a private set intersection protocol so that you & each of your contacts can discover mutual contacts without revealing others.

Signal aren't required to store any personally identifying information: they choose to do so.

[midgetjones]

> 'mom's dad's sister June' also works

Can you expand on that? I'm not sure quite what you mean.

Also, my great aunt is called June.

[wtbob]

> Can you expand on that? I'm not sure quite what you mean.

Sure! It derives from the SDSI/SPKI work of the late 90s, which demonstrated how one can use petnames (i.e., local nicknames) for people, and then refer to a contact's petnames via one's petname for that contact.

So you might refer to a name (mom dad June).

[midgetjones]

Makes total sense now, thanks!

Did you fudge the last example though? My mum's dad is not called June. Or am I misunderstanding?

[wtbob]

Nope, not fudged: the names are hierarchical. So (name mom) is mom in your namespace, (name mom dad) is dad in your mom's namespace, and (name mom dad June) is June in your mom's dad's namespace.