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Messages - oscarandjo

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SGP Task Force: 7 / Re: J Banner 7
« on: August 25, 2020, 13:18:21 »
I've been having a further look at this area, it's something that has really interested me being a Computer Science student.

It looks like some interesting avenues have been explored already.

  • The punch card theory is interesting as punch cards have 12-rows and so do the 3 banners when stacked on top of eachother.
  • 7-bit or 8-bit encoded binary values are an interesting theory as each banner of 112 values is divisible by 7 and 8. If this is the case, what techniques have been used on the text to "encrypt" it? Caesar Ciphers? XOR? Enigma Machine? There's no limit on the complexity that could have been used for the ciphers.
  • Braille seems less and less plausible the more I look into it. Braille characters are typically 2x3, but the banners are each 4-high, making 2x4 braille characters. Some 8-bit Braille conversions exist online, but these appear to be very niche. One thing that might not have been explored is how braille is affected by differences in language, I can see that New Mombasa is supposed to be based in Kenya. Has anyone investigated how languages like Swahili affect Braille encoding? I see there have been attempts to standardise Braille characters, but there are still some individual language quirks. https://en.m.wikipedia.org/wiki/International_uniformity_of_braille_alphabets


There are useful tools that could simplify the process of checking out different encoding techniques to help crack this challenge that did not exist when this thread was first made.

One of the most versatile and easy to use is CyberChef. This is a handy code cracking tool created by the UK's GCHQ. You can access it at https://gchq.github.io/CyberChef/

Here are some pointers for getting started with CyberChef:

You will want to use the transcribed banners from ColdGlider a few posts back http://www.gruntspajamas.com/forum/index.php?topic=228.msg12195#msg12195. You can arrange these in any way you see fit, then enter them into CyberChef.

The easiest way is to paste the banners into a text splitting tool like https://onlinetexttools.com/split-text, remove any line breaks so it's all on one line, and set the text split length (7 or 8 bits).

In CyberChef add the "From Binary" recipe to convert this input into text. After this a number of further "recipes" can be used to try to decode the message. An interesting technique is called "Magic", which tries a series of transformations and looks for how this affects the Entropy (a lower entropy score means it closer resembles natural language).

One disadvantage of CyberChef (which should be fixed in a future update with the addition of a "Byte Length" option) is that it expects 8-bit binary segments. This means if you have 6 or 7 bit splits you will need to pad them with zeroes at the beginning to make 8-bit segments.
Eg: 101010 111111 would need to be padded to 00101010 00111111 to make 8-bit segments.

I hope this makes sense and helps people get started into using different code cracking techniques. CyberChef has loads of techniques, the vast majority I have not yet explored. If you find anything worthwhile, you should be able to share a link which contains your input, "recipe", and output. This should make sharing any discoveries easier.

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FYI your discord username doesn't seem to work.

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