This method requires a "nonce" which is needed again in decryption. If I understand correctly, nonces are important for communication, but for my case they are not needed. Correct?
Also to generate a key from the user entered password requires salt, which must be the same every time.
- Is authenticated encryption really the correct choice for my task? If yes, how should I handle the nonce?
- How should I handle the salt for generating the key? Should I always use the same? Or where should I store it?