Instructions for Assignment 1

Sorry about not providing an explicit document in the first place!

What I expect is a ciphertext obtained by Substitution from an English paragraph, without spaces or punctuation, and without accompanying plaintext (I should be able to break it, so it should be reasonably long), and a ciphertext (with a different plaintext) obtained by Vigenere Cipher, with the same conditions (no spaces and punctuation, no plaintext). Your key for the Vigenere Cipher should be 4-7 characters long.

Tomorrow (Friday the 31st) I will post all the ciphertexts I have received as targets for your skills at cryptanalysis. I will definitely award credit for breaking your colleagues messages (you must show your work). I may also choose to award credit to students whose messages are not successfully decrypted (as incentive not to share your plaintext :-) However, I will only award this kind of credit in cases where I am myself able to decode the message; I don't want plaintexts so brief or so weird that no one can decipher them!

Be aware that if I cannot decrypt your Assignment 1 ciphertexts, I may ask you to submit a new one. The problem I expect with some of them is that they may be too short.

I encourage you to work on cryptanalysis if you have free time during the class period while I am gone next week.

There will be a link on my web page to the publicly posted ciphertexts.

Randall Holmes