These independent variables help to keep each layer as separate and independent from each other as possible. This maximizes and utilizes the benefit of multiple encryption. After all what is more secure: a house with the doors locked, or a house with the doors locked, security cameras on the house, and an attack dog waiting inside the house? A keyfile may also be used to fully maximize security. The keyfile may be any file the user wishes from a picture file to a video file, just make sure to store the keyfile in a safe place as the file cannot be decrypted without it. The keyfile works by supplying separate amount data to the algorithm that isn't accessible from the Salt or password. A cracker could discover your password(s) and still wouldn't be able to properly decrypt your file because they don't have that other data supplied by the keyfile.