Earlier quoted context omitted.
> That has nothing to do with PGP. You could do the same by base64-ing an OTR session (in fact, people do that all the time). But PGP also works for printing stuff on a post-card (or you know, email) - asynchronous communication. While Axolotl does push OTR-like modes towards asynchronous use - they do involve a lot more than getting hold of a public key (say, one published in a magazine, or shown in a frame of a mov…
If you don't need PFS (which you should need) then you can use DH to create the shared key you use for the HMAC. Maybe you could even do an original OTR-like ratchet scheme (only change the key once the recipient shows that they are using the new key) to get PFS. But in principle if you assume that key distribution is "solved" then you can implement the unique parts of OTR.
That's how you'd prefer to bootstrap secure communication with a journalist, or for recruiting people to demonstrate against the current regime in Egypt?
> But in principle if you assume that key distribution is "solved" then you can implement the unique parts of OTR.
How can it make sense to think of it as solved? How do you backup your keys? Your list of trusted keys? Protect them against theft? Alert others to their compromise? Get alerted when keys are compromised?
Key distribution really is the only really interesting problem in secure, trusted, communication (with secure one time pads, most problems go away. The trick is to make sure you have secure one time pads, shared only with the person(s) you want to communicate with...).
Public key encryption opens up some new ways to make the problem easier, but it's just one step in the right direction.