摘要 |
A computer software security and billing system is disclosed in which the application program is enciphered in accordance with an algorithm driven by a numeric key. The user's computer is provided with a hardware security module and a removable billing module, both of which carry unique codes. A security program accesses the application program and also writes information about billing into the billing module. The billing module is periodically replaced so the user can be charged based on amount of usage of the software. |