By proxying calls to the original file, the cracker ensures the program still has access to the complex math or logic it needs to run, only altering the "gatekeeper" functions. The Security Conflict

Because the original code remains mostly untouched, it is harder for simple checksums to detect the change.

Ultimately, the crack.dll backmove is a testament to the ingenuity of reverse engineering—a reminder that in computing, "truth" is often just whatever the library tells the processor, and libraries can be replaced.