Road Map to QuickTime 3
Access keys make it possible to protect data. They allow an application that supplies data to register a password for the data with QuickTime and allows a user to enter the password to gain access to the data. For example, a codec can protect data it compresses with a password, so that it is available only to someone with the password. Similarly, the creator of a movie can require a password to view the movie.
In order to gain access to protected data, the user enters the access key in the QuickTime Settings control panel.
About Access Keys