Encrypted routines impede hackers, protect licenses

摘要

The use of public -key-encrypted algorithms within licensed applications can prevent hackers from cracking the licensed algorithms. Moreover, you can use them to disable licensed features that a user doesn't purchase. Licensing schemes eventually arrive at some critical decision point at which an algorithm decides whether the user is entitled to run that application. If not, the algorithm usually generates a console message or a message box to notify the user of his or her ineligibility. Then, the application terminates or continues in a feature-limited mode. The decision code generally resolves to one of the following (or similar) commands in assembly code: Jump/Branch if not equal (for example, JNE, BNE) Jump/Branch if equal (for example, JE, BEQ).