yeah there are no perfect trade offs: if you control the application server then you just instruct clients to decrypt/give away their data/encryption key still

yeah there are no perfect trade offs: if you control the application server then you just instruct clients to decrypt/give away their data/encryption key still its more effort and more opportunistic (client needs to actually connect that day) so it is safer/reduces likelihood. But a lot of work and issues for the security gain compared to db encryption and proper design (even thus, you know, its not a great trade off either!) In the end I guess we need a truly client-initiated and controlled data handling. HTTP isnt exactly made for that. It tells the client how to handle and control the data, no choice is really made client-side.