Sometimes it is necessary to store data securely on the disk. Hive supports AES-256 encryption out of the box (literally).
The only thing you need is a 256-bit (32 bytes) encryption key. Hive provides a helper function to generate a secure encryption key using the Fortuna random number generator:
var key = Hive.generateSecureKey();
Just pass the key when you open a box:
var encryptedBox = await Hive.openBox('vaultBox', encryptionKey: key);
There is no difference in using an encrypted box.
Only values are encrypted while keys are stored in plaintext.
Make sure to store the encryption key securely when your application is closed. With Flutter you can use the flutter_secure_storage or a similar package.
There is no check if the encryption key is correct. If it isn't, there may be unexpected behaviour.