The (unified) license key should not be a plain-text file, which could be edited by the users. It needs to be secured so that the content is not easily changed by the users.

Evaluate the following design:

• use private keys to encrypt/decrypt the license key
• Qt Account generates unique encrypt/decrypt keys to the Qt Account, per user
  • The user's license key(s) are encrypted by this personal key by the back-end
• the Daemon downloads the decrypt key during the Qt Account Login
  • in pure offline scenarios, the user can manually put the decrypt key in place on the local file system
    • e.g. CI usage
• the Daemon decrypts the key(s) in memory only
• the Daemon provides an API towards the client application integration points (CIP) to query license features