The way these plugins were authorized changed over time, leading to confusion. Early versions used a text-based serial number or authorization code for activation, similar to the DFX Audio Enhancer. Later versions shifted to iLok, a physical USB key that stores software licenses. The shift caused issues for users: "Everything else from my Factory Bundle has made the 'migration' - except the D-Fx plugs keep insisting they need a serial number, even though they're supposed to be Ilok authorized".