Question

What I am doing is making a console blackjack for fun. I want to save the money so users can play day by day but I don’t want to save it in a text file where the user can easily change the amount as they please.

I already thought of making a hidden file or a encrypted file with a password but I don’t like that. I want it to be sort of like when you open some random dll file, all you see is gibberish that you can’t understand.

Answer 1

A bulletproof way to prevent users from tampering with their stats is to store stats away from them, on a remote server. This will require users to be online during play, though. OTOH you’d be able to show a ladder of top players and so on.

An encrypted file is probably the best route if you want offline storage. You just need to hide the file properly.

Before modifying the file, read its modification time. After the update, restore the time. The user will have harder time figuring out which file has changed.

Use an innocent file used by your game with a data block inside allowed by format. It could be an XML file storing the encrypted string in a comment. It could be a JPG or PNG file storing the encrypted string in a comment or EXIF section, at a known offset (so you don’t need to parse the file). WAV, OGG, MP3 also allow inclusion of non-interpreted data. This is not real steganography when you hide your data inside the actual pixel values and such, and is far easier.

I suppose you understand that a determined cracker with a disassembler and a debugger can crack this scheme. But an average user probably won’t bother.