Mật khẩu là thứ chỉ được xử lý chứ không được lưu vĩnh viễn trên máy. Thuật toán thì có

Khái niệm::

• You should not keep your algorithm secret.
• You do not know how much your algorithm is secret.
• You cannot keep your algorithm secret.
• But you can and must keep your password secret, and you can know “how much” secret it is (that’s all the “entropy” business).
  Nguồn:: How valuable is secrecy of an algorithm?