Security Checks Upon First Invocation

The first invocation of a method is the first time the method is invoked from any caller. At this time, for each method marked with the native keyword, the Microsoft VM determines whether the method is a member of a fully trusted class. If it is not, a SecurityException is thrown that includes the message, "Only fully trusted classes can have native methods as members." Because this security check does not depend on the calling context, it only needs to be performed once. If it passes, the check does not take place on future invocations. There is no way to disable this security check.