Due Monday August 31st

Due Monday:

  • A note about daily posts!  Sometimes the tasks may take more than hour, or be frustrating.  In these circumstances, you should feel you have done your due diligence after one hour and hand in what you have (maybe skip over the frustrating task at first).  Then you can come back to them later sometime.
  • Exercise:  What one-time pad key is needed to make the ciphertext ABC decode to WHY?  What one-time pad key is needed to make it decode to NOT?
  • Watch this 3 minute video description of the Affine Cipher (titled “Daily Due Monday August 31st: Quick Initial Description of the Affine Cipher” on canvas Media Gallery).
  • Do the associated worksheet in advance of next class.  We’ll take the worksheet up at the beginning of next class.
  • Using only by hand computations and the “Cryptanalysis Tools” (menu at left), which automates certain computations, decrypt the first few words of the following Vigenere cipher: text file of ciphertext.  (Funny, my browser thinks it is Hungarian!)  Keep a record of your work (i.e.. paste the results and annotate your steps in a text file).
  • Note on the above:  you shouldn’t need to do anything too much by hand; the tools above will be all you need to find the key (just cut-n-paste strings as needed).  For the final decryption, you’ll have to do that by hand, but just do a few words to prove it is english to prove the key is correct!
  • For the completion check, upload your record of your vigenere decryption, and your exercise and  worksheet answers (you can type the exercise and worksheet answers, which are just text, in at the end of the vigenere decryption file so it’s just one file).