Official help for 8b
Home › Forums › The Sixteenth National Cipher Challenge: The Lost Legion › Official help for 8b
This topic contains 191 replies, has 48 voices, and was last updated by Anonymous 2 years, 4 months ago.
02 Jan 18 at 6:54 pm #34019
Any clues for that secret message?02 Jan 18 at 6:55 pm #34020
But how do you know the beginning and end of words?
P.S. Thank you very much to anyone who answered my previous question.
Koala02 Jan 18 at 6:56 pm #34022
Was almost ready to give up but then reread the clue by @Lineage Noir a couple hundreds times and finally worked it out.
Just keep at it and try as many possibilities as you can.02 Jan 18 at 7:09 pm #34030
OFFICIAL CLUE: First, reverse each word, but keep them in the same order, e.g. “I am Joan.” Would become “I ma naoJ.” Then decode bearing in mind it was encoded using the following method. Leave the first letter as it is. The second letter is the first plus the second added together. The third, is the second plus the third added together. Continue till you have done 12 letters, then repeat (so every 12th letter is already correct).
This could also be solved as a Hill cipher using a 12 by 12 matrix where the first row is 1 followed by 11 0s), the second is 1 1 followed by 10 0s, the third row is 0 1 1 followed by 9 0s etc.
Clues for the secret message will be posted in a separate forum.02 Jan 18 at 9:12 pm #34032
what does “os” mean02 Jan 18 at 9:12 pm #34033
What am I doing wrong? First letter is correct, Y. Next letter, currently C, is actually (value of Y) – (value of C) = 25 – 3 = 22 = V. Next letter, currently E, is actually 22 – 5 = Q. YVQ – doesn’t seem like this is going anywhere. What am I doing wrong, this is probably a silly mistake.
PS Joan, did you mean that the third row is 111 following by 9 0s? i.e.
As the matrix?02 Jan 18 at 9:13 pm #34034
How do you “add” the letters?02 Jan 18 at 11:59 pm #34039
Joan said “0 1 1 followed by 9 os”
…02 Jan 18 at 11:59 pm #34040
I think that it is plaintext = ciphertext – keytext, using A=0, B=1, C=2 etc, and mod 26 arithmetic
Thus the second letter of plaintext will be C – Y, which is 2 -24, which is 4 (mod 26) and thus the second letter of the plaintext is E, which makes more sense 🙂03 Jan 18 at 12:00 am #34041
Noaj, Noaj, Noaj (it’s Joan backwards)
No wonder this is set by the University of Southampton, you’ve really pushed the boat out on this one
Danke für die Herausforderung.03 Jan 18 at 12:00 am #34042
0s is zero’s not os as it looks like in this font03 Jan 18 at 1:04 pm #34049
Am I close.
Also what comes after the forth of January. Do the best get picked03 Jan 18 at 1:06 pm #34050
Desperately trying to limp to the finish line here (the white flag of surrender has been hoisted for some time now!!). I have followed, with immense gratitude, Joan’s (and others) hints and tips but am still fumbling in the dark.
I have reversed the letter order but maintained the word order, so the first word was originally TVVERECY, and reversed reads YCEREVVT. I have then used the method explained by @Tommo above, which gives me a decode of YECNNRAY.
I am happy to keep on plodding on with my decode, but at the moment, it aint making much sense!! If I am going wrong somewhere, please can SKS point me in the right direction?
Thanks!03 Jan 18 at 1:06 pm #34051
i got 99.99 what more03 Jan 18 at 1:09 pm #34056
Joan, when you say the third letter is encrypted by adding the second to the third, does this mean the second after it’s been encrypted or before?
You must be logged in to reply to this topic.