I am developing an android app that uses the safe_app_java. So far all of the time keys that I use are either predefined constants or just a int sequence, i.e. there is nothing to “hide” that needs to be encrypted. At the same time in the examples keys are encrypted.
What are the potential use cases where the keys need encryption? As far as I can image the keys should be just a unique identifier and not contain sensitive data (if the system is designed properly).
A unique identifier could also be sensitive data. E.g. you could have a map with family members, identified by name. The RDF emulation layer encodes the IDs as keys, such IDs might also be sensitive — or all the keys combined could be sensitive.
Encrypting the key/value is optional, in the example we just wanted to showcase the encryption feature. As @bzee had mentioned the key could be a sensitive data as well so you might want to encrypt it.