There's an accompanying talk (and slides) that was given at apachecon earlier in the summer. I heard some of the talk (from the OP linked page.. not in person) . The essence of DTA seems to be that it creates key-pairs for both ends of the communication (client and server), multiple DTA's combine to create the private keys and the keys are being distributed to the client side through some out-of-band "protected" channel.

The use-case is not billions of browsers connecting to millions of webservers (as in PKI based TLS) but a small number of controllable client end points (a native app binaries on mobile or IoT devices) connecting to a handful of servers.

The mental image I came away with (not sure if it's 100% correct) is think of an distributed infrastructure to create SSH key-pairs (where PIN is equivalent to the passphrase for the private key).

Wonder if anybody from the Milagro team feels like responding to this thread. It's on HN front-page right now and would be a great chance for the creators to engage with the community.