Merge branch 'master' of https://github.com/7SLEVIN/cryptanalysis

project3/README.md

@@ -1,13 +1,13 @@
 Project 3
 =========
 
-A simple Python script for cracking a known ciphertext with known
+A Python script for cracking known ciphertexts with a known
 encryption algorithm.
 
 
 ## Content
 
- * `Breaker.py` - The script used for breaking the ciphertext
+ * `Breaker.py` - The script used for the "breaking" of the ciphertext
  * `ciphertext.txt` - The file containing the ciphertext
  * `plaintext.txt` - The produced plaintext from the ciphertext
 
@@ -18,17 +18,27 @@ To decipher the ciphertext, run the `Breaker.py` script with an input
 file, containing the ciphertext:
 
     $ python Breaker.py ciphertext_sheet3.txt
-    
+This requiers the ciphertext file to be in the same directory as the script. 
 This will produce a file called plaintext.txt, if it is successful.
 
+## Functionality
+
+The script has a couple of functions that will be described:
+
+ 1. `calc_time(date, date_format)` This simply finds the seconds from 1.1.1970 to the given date.
+ 2. `update(s)` This function is the update function given in the assignment for each new key initialization
+ 3. `load_cipher(inputfile)` takes an inputfile and puts every character in a list and returns it
+ 4. `encrypt(c, key, i)` takes 3 variables a caracter form the caracter list the a key and i which is from the start point to end point of time when the file could have been encrypted.
+ 5. `check_plain(plain)` this function checks if our decrypted text is equal to any of our plaintexts.
+
 
 ## Logic
 
 The script essentially runs a **smart brute-force** attack:
 
- 1. We first calculate the relevant time interval the cipher was
+ 1. We first calculate the relevant time interval within the cipher was
  created.
- 2. Load ciphertext from file
+ 2. Ciphertext loaded from file
  3. Start brute-force search for every possible time
      1. Initialize key with current time / internal state
      2. Encrypt every character in ciphertext with current state