[devit]

Well, not really.

You could have a single secure system that holds encrypted session keys (and encrypted data if needed) for all the calls, and have it give them out under arbitrary logic, which could include rate limiting, multiple approval and publishing access requests (maybe after a delay), which would prevent "no encryption" from happening, assuming that system is properly secured.

Non-physical security can obviously be made perfect, and physical security can be achieved by launching the system hardware on a rocket, which still allows to communicate with it but makes physical access obviously impractical.

But obviously the issue is that the users have no incentive to use such a program as opposed to one without "key escrow", and there are plenty of PCs and Android smartphones on which arbitrary software can be installed.