National Cipher Challenge 2019 › Forums › National Cipher Challenge 2019: Countdown to Catastrophe › Second part 9b
4th January 2020 at 9:13 pm #45114George112nMember
We have got the 24 characters part, in the way hinted at by the forum and have assigned each one a letter using frequency analysis but although the IOC and the frequency of letters fits with normal English text, we cannot crack the resulting text.
Are we almost there or do we have a lot further to go?
Harry could you provide a hint on the second part please?4th January 2020 at 9:16 pm #45126HarryKeymaster
You really are nearly there. The second part is a report by NASA so you could try looking for cribs like Memo, spacecraft, Apollo and so on. Can’t say any more I am afraid.
Harry5th January 2020 at 12:25 pm #45133George112nMember
Ok thanks. We have a program that’ll find Apollo, Csakka etc so we will try that.6th January 2020 at 12:08 pm #45134Mhd25Member
I am at this exact same stage and am really confused Harry could you please at least give a small detail as to what has been done to the text?6th January 2020 at 12:10 pm #45138HarryKeymaster
The text has been encrypted using a variation on the triffid cipher, where instead of using three ternary characters for each alphabetic letter, a combination of binary and ternary have been used. You can figure out the convention by looking at where the 2s appear, and by thinking about how to use binary and ternary to represent (most of) the alphabet.
Does that help?
Harry6th January 2020 at 10:07 pm #45144Peter-k-tompkingmail-comMember
Harry – that’s a fascinating insight that I made absolutely no use of at all – mainly because I didn’t see such subtleties until after my solution emerged. If it’s OK at this late stage, is it too much to suggest to those still working at it that a more direct attack on the four digit numbers that are generated by the fractionation in the style of a trifid cipher by simple frequency analysis and trial and error will yield results
The key word and the patterns in the 2’s only emerged later for me.
- You must be logged in to reply to this topic.