Private input support

We need to add support for the private inputs such as access tokens or private parameters. We can start with checking the TLS-Notary theoretical results and try implementing the secret sharing MPC procedure between the TEE server and the client.

Start by reviewing the TLS-Notary theoretical results mentioned in the issue, then trace the existing TEE server and client boundaries. Define the secret-sharing MPC procedure needed for private inputs such as access tokens or private parameters; done means the support is implemented across both parties and its behavior is verifiable.

Written by the indexing model from the issue text.