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> The game data files look like this; encrypted, unreadable text. Fortunately, it turned out that they were encrypted using an xor cipher. This means that we ca
by nneonneo 8y ago
> The game data files look like this; encrypted, unreadable text. Fortunately, it turned out that they were encrypted using an xor cipher. This means that we can fairly easily write a script to get a list of questions and answers in human-readable, decrypted form.
I mean, it doesn't much matter how these things are encrypted - since they have to be decrypted to display the questions and answers on-screen, the code and any necessary keys will be present in the game code. You'd only need to reverse engineer the ROM enough to know where the decryption code is, and invoke that code (or reverse it and write a compatible implementation). It just so happens that the encryption is weak enough here that reverse engineering is not required.
- jamesough 8y agoYes, and the decryption code had been bundled into the binary! I tried inspecting it as you say but it seemed easier to just solve it by hand.
- yadaeno 8y agoUnless the key could be in a separate hardware component.
- brian-armstrong 8y agoThis isn't necessarily true. A lot of machines like this use a security dongle to perform decryption which means it is very hard to get the data except by scraping it while it's running (and even then, this can be quite hard)