I hope that eventually, .onion services can get DV certs so their proxy can serve that cert if the user connects directly, bypassing the need to connect through an exit node for the first connection.

One thing I'm curious about:

> While bad actors can still establish a fresh circuit by repeating the rendezvous protocol, doing so involves a cryptographic key exchange that costs time and computation.

Is there some way for the destination .onion service to scale the difficulty of this rendezvous challenge, so this proof-of-work scheme can continue to work? It would be sad if they get to the point where it's no longer an effective rate limit and have to go back to serving CAPTCHAs for every new circuit.