Program 1 -- Caesar Cipher

The official write-up and description of Program 1 is given in this PDF file Caesar Cipher--Implementation and Ciphertext attack.

Encryption/Decryption

The following three files may be used to test your encryption/decryption implementation.

file0.txt Original plaintext file
file0.txt.cipher file0.txt encrypted with key 43
file0.txt.plain Decryption of the file file0.txt.cipher with key 43

Character Frequencies

You will need to be able to determine the character frequencies in the following file: disseration-intro.txt.

Please note: I will not be providing the character frequencies for this file. You may store your computed frequencies to a file in any manner that you so choose, so long as you can read these values into your ciphertext attack tool.

Ciphertext Attack tool

Use your ciphertext attack tool to determine the top-five likely decryption keys for the file: file1.txt.cipher.

Note: It should be fairly obvious to determine if you have used the correct key to decrypt this file.


Last Update: 17 February 2007