HTTPS, works good enough

Secure data transport over the Internet today is common. 

The server gives the client a public key. The client encrypts data with said public key and only the server keeps the primary key, unobserved by humans in our case.  only the server;s primary key can decode the data. And we do it both ways for peer to peer.

Thus we are back to our simple assumption, a processor can generate a secret key and keep it unobservable in address space, but allow public key generators from it. It is easy to see that a modern processor could do this and be mostly self validating.

So, from sandbox point of view, very secure point to point links are available in the internet.  The entire premise of swap net is the ability of the human to securely send a signature to the notary that the notary can trade via power of attorney.  Back to simple legalities, insure bid and bot.

Underneath we have an HTTPS net connecting processor cores.  This is a great network to make the secure interpreter, either node.js or python. Be careful adding the application layer.  Any short script can can engage in  exchange with any other, the scripts finite, and provable by exploration apriori.