Official help for 8b
Home › Forums › The Sixteenth National Cipher Challenge: The Lost Legion › Official help for 8b
- This topic has 191 replies, 48 voices, and was last updated 6 years, 3 months ago by
Anonymous.
-
AuthorPosts
-
29 Dec 17 at 9:33 pm #33913
Anonymous
InactiveAh-ha! So it’s a hill cipher, but not that complex! That is interesting but how does a hill cipher work?
29 Dec 17 at 9:33 pm #33914Inactiveb.snomolos,
NEVER underestimate the challenge!!!!
Last year, a 2×2 hill cipher was used for 8A, and 8B… don’t ask!29 Dec 17 at 9:34 pm #33916InactiveI remember that last cryptic clue from 8a last year Joan, but it already tells us things we already know!! And unless the key is the same as last year as well as this first cipher, then I’m stumped. I have some theories about reversing each word’s lettering and the other cipher, but none of it works!! 8b – you truly have done it again 🙁
30 Dec 17 at 12:16 am #33922InactiveI’m am soooooo confused on how to solve and figure out how to use a hill cipher!!!!
30 Dec 17 at 2:19 am #33924InactiveOFFICIAL CLUE: 12 is a number you may be interested in.
30 Dec 17 at 12:44 pm #33925InactiveThe Hill Cipher was used in last years Challenge but could someone please tell me what else was used to crack 8b!?
Thanks30 Dec 17 at 12:45 pm #33926InactiveHi Joan
I don’t know why my post has not been allowed through. People are thinking it is a Hill Cipher but that should not have been a cipher in this historical context. In the meantime I will stick with Vignere combinations with a key length of 12.
regards
Sleuth30 Dec 17 at 4:15 pm #33929InactiveAs for how the Hill Cipher works:
One takes an reversible (has an inverse Matrix, which is a Matrix in relation to the first Matrix where Matrix A * Matrix B = Matrix B * Matrix A) n*n Matrix – this is the key. One then splits the text into groups of letters size n, and then writes each of these groups of letters as a Matrix. From there, one multiplies each Matrix of n letters by the key, modulus 26, to create a new set of Matrices. These Matrices are then converted back into letters, which are then strung together to create the ciphertext.
For decrypting the ciphertext with the key, one works out the inverse Matrix to the key Matrix, taking modular arithmetic into account (this is the bit I struggle to get my head around, because of things like 1/3 = 9 if you’re multiplying in mod 26), and then encrypt the cipher text with the inverse Matrix, as described above to get the plaintext!
ADuptheTotal1 (great name by the way!) I don’t remember a 2*2 being used in 8B? As I understand the set of letters obtained from the numbers was encrypted with monoalphabetic substitution?
Ooh, and just whilst writing this I’ve had a thought, imagine how mean it would be if 8B was like a 12*12 Hill Cipher!
30 Dec 17 at 4:16 pm #33930InactiveEmiloi88, as described in the ‘How The Winners Won’ booklet, one removed all the twos, then split the text vertically at the spaces left by them. One then read off binary letters from top to bottom, left to right, in their groups of 5, and then solved a monoalphabetic encryption from those letters.
31 Dec 17 at 12:03 am #33933Inactivewhat on earth are they yearning for? we’re yearning for another hint on how to conquer the hill… if it is a hill…
31 Dec 17 at 12:12 am #33911InactiveThe Romans would not have known of a Hill Cipher . I have been working on picture clues of Mount Olympus and Eagles but could not get Quagmire or doubly encrypted Vignere combinations to work.
31 Dec 17 at 12:12 am #33934Inactive8A was encrypted with a hill cipher. 8B was the unique one.
31 Dec 17 at 12:13 am #33935InactiveWe have tried and tried … suspect a 2×2 Hill cipher but have no idea how to identify the key word or matrix and don’t understand how the number 12 is relevant. Also, should we reverse the words before or after the Hill Cipher? We are getting close to the end and running out of time – it would be good to finish, please!
31 Dec 17 at 12:13 am #33936InactiveWhat are matrixes?
31 Dec 17 at 12:13 am #33937InactivePretty sure that the vignere wasn’t around then either. Nor the thing used to encrypt 8B
-
AuthorPosts
- You must be logged in to reply to this topic.