To verify the integrity of the ZIP file, you can use an MD5 checksum tool. The MD5 checksum for the God of War 3 ZIP file should match the one provided by the file source.

If you want a serious technical paper, here are three valid directions:

However, there are several factual issues here that make a legitimate deep paper impossible — but I can explain why and offer an alternative topic if you're interested in emulation, file compression, or PSP game modding.

If you want a genuine Kratos experience on your phone, you should focus on the titles actually built for the PSP and fully supported by PPSSPP: God of War: Chains of Olympus God of War: Ghost of Sparta