| 摘要 |
<p>A method and an apparatus for handling the access to optional features in a computer system, such as a telephone exchange, are disclosed. The computer system comprises an encryption key. Each feature is associated with a feature identification integer (FI), a feature activation integer (FA) and a data tag (FD). To activate a feature, the user enters a number of integers, received from the system vendor and encrypted using the same encryption key found in the computer system. The integers are decrypted, an arithmetic operation performed, and the result compared with the integers associated with the feature. If there is a match, the feature is activated, forever, or for a period of time determined by the integers. The use of features may be stored in a log (11), which may, together with a log indicator (9), be used by the vendor to check the use of optional features.</p> |
