1. Method for protecting an application program executable on a computer against reverse engineering, said application is created to run with at least one selected dynamic link library on said computer, characterized by the steps of: adding a specific dynamic link library loader to the executable application program, said loader either contains or has access to said selected dynamic link library (DLL); modifying the references from the application to said dynamic link library (DLL) such that upon loading said application program and said loader into the main memory of the computer, said dynamic link library (DLL) is initialized by said loader instead of the operating system;