> a secure way for me to limit when and how you can use those That would be having them access the file in a restricted environment (literally, guards and stuf

> a secure way for me to limit when and how you can use those That would be having them access the file in a restricted environment (literally, guards and stuff). You can't have people accessing your secrets in the comforts of their own homes and at the same time not be able to reproduce them in some form – even if an exact duplicate of the original data would be infeasible to obtain.