Custom? IO steam Encryption/Conversion??

[Tsukihime]

There is a bunch of interesting information available about Cryptanalysis


Let me give an extreme example of what I mean, as it is something different.


Say we want to encrypt our png-files. PNG-files have a particular header with the first byte being 0x89.


Encryption: Change first byte from 0x89 to 0x79.


Decryption: Change first byte from 0x79 to 0x89.


Doesn't get much simpler than that. Should someone try to open the picture file they'll get a corrupted error or something like that.


Now let's say that they open the file in a text editor or hex editor. PNG is there in plaintext.


Why can't it be opened?


*opens a working PNG-file*


*compares and notices the different first byte*


*changes first byte and checks if that works*


Hey.... encryption broken


*hugs*


 - Zeriab

I've seen this in many games where they simply took off the header or changed the tag names around and you see a lot of people coming to reverse engineering forums crying about things not working etc etc.


Especially since most tools are written so that they check the header and go "oops, this isn't a PNG, bye bye".


Doesn't really make sense to say "well, this might be a PNG even if the first 4 bytes didn't say so...so let's keep reading!"


For me, hex editor is the natural way to look at unknown data, but for most people, it is likely a text file or give up.

 

[Zeriab]

Lol, so your underlying point is, its pointless. ?

I get what you mean about how the game must contain the secrets so in the end, someone whom is able to interpret the secrets to their true meaning will always be able to cause 'damage' wherever they see fit (should they so choose to). But I mean, isnt it at least worth making it a little more time consuming in the hope of being able to deter a few folk?

Also, I never thought of something to simple for an encryption method

Certainly got me thinking now...

Nope. Even though that as long as all secrets must be sent with the game the problem is practically unsolved, I believe there is still value in some encryption.

Basically from my point of view the encryption should be strong enough that a deliberate conscious action is required by the end user to break the encryption.

Yes, I have tried a game where I did accidentally circumvent the DRM. It started spewing out unencrypted resources, and created another .exe file which appeared not to tricker the time limit counter. :x

*hugs*

 - Zeriab

 

[??????]

Lol I have never accidentally avoided any DRM systems. (note: accidentally...)

And yea, thats basically my view on it. As long as I can make it at least a little harder than opening some RGSSAD crap and stealing all my hard work, which is certainly possible.

Hell, I could just move everything important into various 'patches' that are constantly held on the computer and read at runtime into the script editor, so even when they break into the files via RGSSAD, they still dont have my code.

And with the whole .so thing, a lot more is possible. Still a few restrictions,but at last some things can be a little more hidden there as well