Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Hill Cipher- Potential Cribs for 3x3 Matrix

  1. Dec 8, 2017 #1
    1. The problem statement, all variables and given/known data

    I've created code to crack a Hill Cipher (n=3).
    I'm unsure which cribs to try to crack a specific code.
    Would anyone mind posting ideas? The crib must be 9 letters in length.
    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. Dec 9, 2017 #2


    User Avatar
    Science Advisor

    Or have you only created code to encrypt and decrypt using the Hill Cipher, given the key? Cracking a code involves cryptanalysis, which identifies the type of cipher employed, then applies statistical tests to identify the probably key, language and message content.

    A crib will require knowledge of the sender or situation. What do you know about the source? Do you have any idea of phrases that may have been enciphered in that example? A restriction to only letters, say modulo 26, would mean that numbers must be spelled out in full. If this was an academic exercise then you need to guess at the key or text likely to be chosen for the demonstration. I would start with something as obvious as; “hillcipher”; which unfortunately, has too many letters.

    Does the full stop indicate the use of modulo 27?
    Please post the full encicode as an ascii.txt file rather than a blur.png
    or can you give us a link to this example on the web?
    Last edited: Dec 9, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted