[messaging] Introduction secrets and "unlinkable rendezvous" protocols

[Brian Warner]

On 2/15/14 4:50 PM, Trevor Perrin wrote:

> Here's a better sketch of the "DH rendezvous" idea, fwiw.

I like it, especially the way it removes the need for a single global
mutable rendezvous server. It's much easier to set up a single global
*immutable* publishing system.

> During an offline meeting, users would exchange their long-term
> fingerprints. They would then enter the other party's fingerprint into
> their app, which would perform some pre-rendezvous steps:
>  - Retrieve the other party's introduction cert by querying one of the
>    mirrors.

Would that require some sort of PIR protocol? Seems like the mirrors
could learn who's interested in whom at about the same time, and thus
deduce the connection.

cheers,
 -Brian