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: Decoding encryption with matrices

  1. Dec 8, 2004 #1
  2. jcsd
  3. Dec 8, 2004 #2

    Diane_

    User Avatar
    Homework Helper

    Find the inverse of A and left-multiply it by the coded matrix. Call B the message matrix, and B' the coded matrix. You get the coded matrix by finding

    AB = B'

    Get the uncoded matrix by taking

    A^(-1)B' = A^(-1)AB = IB = B
     
  4. Dec 8, 2004 #3

    shmoe

    User Avatar
    Science Advisor
    Homework Helper

    They give the inverse matrix of A just above the sentence "I LOVE MONICA". It appears to be off though, and is actually the negative of the inverse.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook