2020/2020-challenge3.md

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  11     display_name: Python 3
  12     language: python
  13     name: python3
  14 ---
  15
  16 ```python Collapsed="false"
  17 from szyfrow.affine import *
  18 from szyfrow.keyword_cipher import *
  19 ```
  20
  21 ```python Collapsed="false"
  22 challenge_number = 3
  23 plaintext_a_filename = f'plaintext.{challenge_number}a.txt'
  24 plaintext_b_filename = f'plaintext.{challenge_number}b.txt'
  25 ciphertext_a_filename = f'ciphertext.{challenge_number}a.txt'
  26 ciphertext_b_filename = f'ciphertext.{challenge_number}b.txt'
  27 ```
  28
  29 ```python Collapsed="false"
  30 ca = open(ciphertext_a_filename).read()
  31 sca = sanitise(ca)
  32 cb = open(ciphertext_b_filename).read()
  33 scb = sanitise(cb)
  34 ```
  35
  36 ```python Collapsed="false"
  37 (word_a, wrap_a), score_a = keyword_break_mp(sca, fitness=Ptrigrams)
  38 print(word_a, wrap_a, '\n')
  39 pa = keyword_decipher(ca, word_a, wrap_a)
  40 print(pa)
  41 ```
  42
  43 ```python Collapsed="false"
  44 open(plaintext_a_filename, 'w').write(pa)
  45 ```
  46
  47 ```python Collapsed="false"
  48 (word_b, wrap_b), score_b = keyword_break_mp(scb, fitness=Ptrigrams)
  49 print(word_b, wrap_b, '\n')
  50 pb = keyword_decipher(cb, word_b, wrap_b)
  51 print(pb)
  52 ```
  53
  54 ```python Collapsed="false"
  55 word_b, score_b = simulated_annealing_break(scb, fitness=Ptrigrams)
  56 print(word_b, '\n')
  57 pb = keyword_decipher(cb, word_b)
  58 print(pb)
  59 ```
  60
  61 ```python Collapsed="false"
  62 keyword_decipher(cb, 'caistor', KeywordWrapAlphabet.from_last)
  63 ```
  64
  65 ```python Collapsed="false"
  66 open(plaintext_b_filename, 'w').write(pb)
  67 ```
  68
  69 ```python Collapsed="false"
  70
  71 ```