Avoiding spoilers in an open source environment

SynapticBytes

To spice up my game a little, since it’s fairly basic (in concept at least), I’m adding an achievement system. I was wanting to make it a surprise element, so part of the game was for players to actually figure out what they have to do to unlock some of the achievements. The problem is, how do you introduce an element of surprise in an open source environment, where all of the code is easily viewable by any player?

I’m not looking for hard-core cheat prevention, more just obfuscation so the casual observer doesn’t accidentally get their experience ruined. Options I can think of, from simple to hard is : -

Spoiler Alert
Just a simple text caution that if you look any further here, you will be spoiled. Some people just can’t resust a peek though, even if they’d rather not be spoiled.
String encoding
Create an encoding algorithm for any strings, which is where most of the spoiling will happen, but that only hides some of the surprise.
Code Encryption/Decryption
I’m not sure if this is even viable in MiniScript/MiniMicro. It seems like it should be. What I’m thinking of is having the spoiler code in an encrypted file, and pre-processing to decrypt, then load as a library at the start of the game. It’d be a bit of work to implement though. I’d have to find an encryption/decryption algorithm that works with a MiniScript file. Also if the decrypted file is saved to disk, then it’s still possible for someone who wants to, to just break out of the code and look, but as I said, if someone really wants spoilers, I’m not trying to stop them.
Code Obfuscation
Similar to above, but doesn’t need decryption as the encoded file is still executable, just hard to read. However code obfuscation would require a fully custom written encoder for MiniScript, which is a big job.

So, any thoughts on options, pointers if others have done it already, or the value of even trying?

Thanks. Russell.

jstrout

That's an interesting topic.

But my first thought is, this is the age of the Internet. Even if your game were delivered as a compiled binary with military-grade encryption, as soon as somebody figures out what the achievements are, they'd be posting a YouTube video about it or describing it on a wiki somewhere. And anybody who wanted to find out would just google it, and find the answer far more easily than reading through the code.

So, I probably wouldn't bother trying to hide it. Most players won't go looking for answers, and if somebody does, I'd rather have them read code than read a wiki page anyway. 🙂

On the other hand, maybe encrypting the strings might be worth a small amount of effort, for a small amount of spoiler prevention.

SynapticBytes

I see it like trying to prevent movie spoilers, when you open up Apple news on Star Wars release day and see a headline saying “Yoda Is alive!”. You see it before you even realise what you’re reading. So if I have a library file called “Achievements”, I don’t want someone to open it and see all the descriptions explaining them laid out at the top of the file.

Obfuscation as an academic topic actually interests me. I remember way back when, programming on a TRS-80 and Commodore 64. The length of your code was a big factor in its execution speed. So people created code compactors to strip every redundant character from the code. The result was obfuscated code not for security, but performance. Ever since then, the idea of code compaction has just seemed like a neat idea to me just from an efficiency point of view. To this day, you will still see in my code, preferences for things like i and j as iteration variables, rather than more verbose and descriptive names.

SynapticBytes

Hmm, an XOR algorithm would be simplest, but alas there is no bitwise operators in miniscript. I seem to be heading down a 🐇 🕳

jstrout

Hehe, that's true. I think you'd be fine with something simple, like ROT-13 or a substitution cipher. (Obviously you'd want to pick a fixed cipher alphabet, rather than the random one shown in the latter example.)

This reminds me of back when you got magazines with code listings for you to type in. Occasionally there would be some important text that needed to be kept secret to avoid spoiling the game, and it would be encrypted in some way. Of course this made it a real PITA to type in. 😛

SynapticBytes

Well since we had the binary function in Rosetta Code already, I started from there and now have a working XOR solution for string encoding. Highly insecure, but good for string obfuscation, even though I can't really hide the key, Another notch for my utility library at least 🙂 My utility code is now about 20% of my whole game code.