isn't.
The reason you'd use a "Checksum" and to verify the integrity, of the games SIZE
The minute ANYTHING is injected into a application the file size is altered, a simple check of any kinda injection into game memory would then terminate the game.
What SlicedTime was trying to say was that you'd need a checksum for literally every possible configuration of all memory states that get updated based on all possible configurations of memory in the game (Memory is non-static). Also I think you're confusing file sizes with memory storage, Memory is volatile storage which can be altered via different application states without altering the actual files themselves (hence why archived files can be run in-archive with the memory states not needing to update the file states), file 'size', storage or non-volatile memory I believe is what you're talking about with your checksum, this would not really help with hack prevention as injections into game/application memory does not necessarily alter the file sizes of the application.
Another aside mentioned above is that different OSes and OS revisions use different memory allocation pointers and inherently produce different checksum results (as Neospecter said), essentially this means it would be incredibly difficult if not impossible to make a verification system based on Checksum which is sufficiently permissive to allow many people across different OS types, versions, and kernel revisions and to play the same game.
Also please stop trying to belittle people rather than having a discussion, it really does your points no justice and makes you seem butthurt. (less)
