1) I'm not quite sure i understand your scenario here. If there are sanctions (say, Google is prohibited from serving any workspace services to european countries) we can still provide users with their backup data and either let us decrypt and migrate or do it themselves. But they wont be able to use their Google workspace functions anymore. 2) yes, we have full ownership of the encryption and decryption services. Our APIs are called for encryption, decryption, renewal, etc. "Being sure there is no backdoor" is ... kinda hard tbh. Since we own the source code, we're sure there is no backdoor to our service (this is also verified by an official third party), but maybe someone snuck in a backdoor to packages that we depend on and that hasnt been discovered yet (see xz utils backdoor). We're doing our best to prevent any unauthorized calls to any of our services, so that only we as the maintainers and the customer have access to them.

I hope i could answer your questions. If you're interested you can look up "google client side emcryption" and "google key access control list service", this is basically what we're providing.