QuickTime 4 Reference

System and Application Access Keys

There are two kinds of access keys:

system access keys
application access keys.

Data protected by a system access key can be unlocked by any QuickTime caller on the computer. Data protected by an application access key can be unlocked only by QuickTime clients for that application.

System access keys are useful for data that needs to be used by more than one application. When a system access key is registered for data, applications do not have to perform any additional registration to unlock the data. In contrast, application access keys are normally registered by the application in which the data is available, and each application registers the application access keys it uses. For example, a CD-ROM vendor can register the same application access key for all the data on the CD-ROM, which makes the data available to the application on the CD-ROM (such as a game) and inaccessible to all other applications. This prevents browsing of the data by users.