get_state should return an encrypted and signed value (TLS into enclave?)

[brenzi]

the client should be able to verify that what a worker sends him is indeed coming from the enclave.
Moreover, the payload should be encrypted such that the worker doesn't learn anything about the query

[brenzi]

the enclave doesn't have a key agreement with the user and therefore can't encrypt the response. We should actually have a TLS connection right into the enclave for worker-api which could also cover authentication (if X.509 supports ed25519 signatures???)

[haerdib]

This issue should be fully covered by issue #202.
@brenzi should we keep this issue open either way?

[brenzi]

We can close this one as it is fully covered.