I found an iOS app that claims to save all user data only encrypted. But the app never asks me for a password. Is it even possible that the app encrypts the data in a useful way? I do need see what difference it makes if I try to access the data or someone else if there is no password.
I can imagine that data is send over the network encrypted with a random local stored key. But for local storage, the key would have to be stored at the same place as the data making the encryption useless. Is that correct?