Let $LOGIN be your departamental login, of the form f3lastna.  The 
individual files $LOGIN.pdf are available with the full assignments 
and associated data: replace README with $LOGIN.pdf or the relevant 
filename for the data file.

The data files for the assignments are of the form $LOGIN.k.txt.
You should replace $LOGIN with your departmental login name, and the 
k with the integer as indicated below.  All data files are located 
in the current directory of this README file.
 
Question 1 is a Vignenere cipher, for which the ciphertext is:

    $LOGIN.1.txt

Question 2 is a substitution cipher, for which the ciphertext is:

    $LOGIN.2.txt

Question 3 is a product cipher, for which the ciphertext is:

    $LOGIN.3.txt

Question 4 is a one-time cipher, for which you are given three ciphertexts: 

    $LOGIN.4.txt
    $LOGIN.5.txt
    $LOGIN.6.txt

Question 5 also requires two data files:

    $LOGIN.7.txt
    $LOGIN.8.txt

The first specifies an array of ciphertext images.  Each of the sixteen 
rows represents the ciphertext images of the sixteen plaintexts, under 
the eight possible keys.  

The second represents the plaintext probabilities.  The keyspace 
probabilities are all assumed equal, i.e. 1/8.