Hello i am developing an app that collects some private data from my clients. My clients wont like it if i am able to read the data. So the data is encrypted in cleint side with a key say "xyz",which is auto generated when client install the app/make a account and only with this key can someone read this data. Now when the client login from a new device i want the client to generate the key, and use it to retrieve the data . How do i do that? I cant save xyz in server since then i will have both key and encrypted data, I cant generate xyz with password or User details since i will have them and i knows how to create the key from that data
Is there a way to achieve this without saying to client Trust me am truest worthy. Or make your own key!?