Question

所以我在python中编写一个caeser密码，我有一个强力选项，看看它是否能解码一个随机偏移的单词。出于某种原因，我得到错误：

Traceback (most recent call last):
  File "C:\Users\nameredacted\Desktop\Python\CipherV2.py", line 60, in <module>
print(getTranslatedMessage(mode, message, key))
  File "C:\Users\nameredacted\Desktop\Python\CipherV2.py", line 47, in getTranslatedMessage
ciphertext += alpha2[ (alpha1[i] + brutekey)]
KeyError: 26

我的代码是：

from PyDictionary import PyDictionary
import enchant
MAX_KEY_SIZE = 26
dictionary = PyDictionary()
d = enchant.Dict("en_US")
alpha1 = dict(zip("ABCDEFGHIJKLMNOPQRSTUVWXYZ",range(26)))
alpha2 = dict(zip(range(26),"ABCDEFGHIJKLMNOPQRSTUVWXYZ"))

#gets if the user wants to encrypt or decrypt
def getMode():
  while True:
      print('Do you wish to encrypt, decrypt or brute force a message')
      mode = input().lower()
      if mode in 'encrypt e decrypt d bruteforce bf'.split():
         return mode
      else:
         print('Enter either "encrypt" or "e" or "decrypt" or "d" or "bruteforce" or "bf".')

#gets offset value if needed
def getKey(mode):
 key = 0
 if mode[0]=='b':
       pass
 else: 
       while True:
           key = int(input('Enter the offset number (1-%s)' % (MAX_KEY_SIZE)))
           if (key >= 1 and key <= MAX_KEY_SIZE):
              return key

#translates the message
def getTranslatedMessage(mode, message, key):
  ciphertext=''

  if mode[0] == 'd':
        key = -key
        for c in message.upper():
              if c.isalpha():
                    ciphertext += alpha2[ (alpha1[c] + key)]
              else: ciphertext += c
  elif mode[0] =='e':
        for x in message.upper():
              if x.isalpha():
                    ciphertext += alpha2[ (alpha1[x] + key) ]
              else:
                    ciphertext += x
  else:
        while True:
              for i in message.upper():
                    for brutekey in range (26):
                          ciphertext += alpha2[ (alpha1[i] + brutekey)]
              print(ciphertext)
              if d.check(ciphertext):
                    break

  return ciphertext

mode = getMode()
message = input("please input your message")
key = getKey(mode)
print('Your translated text is:')
print(getTranslatedMessage(mode, message, key))

感谢您的阅读，如果您能评论您可以看到的任何改进，也感谢您。

Answer 1

如@TemporalWolf的评论所述，alpha1[i] + brutekey在某些时候会超过25。假设消息是"XYZ"，并且从0开始的broutekey将是2。然后alpha1["X"] + brutekey = 25，这没关系。但是alpha2[ alpha1["Y"] + brutekey ]会引发KeyError。要解决此问题，您可以使用模运算符。它允许您像模拟时钟一样进行计算：8 + 6 = 2 (mod 12)。在python中，模运算符由%表示。你的代码是：

else:
    while True:
          for i in message.upper():
                for brutekey in range (26):
                      ciphertext += alpha2[ (alpha1[i] + brutekey) % 26]
          print(ciphertext)

另外我想你想改变那两个for循环的顺序。通过这种方式，您可以修复邮件的一个字母并浏览该字母的每个brutekey。那只是字母表。

else:
    for brutekey in range (26):
        for i in message.upper():
            ciphertext += alpha2[ (alpha1[i] + brutekey) % 26]
        print(ciphertext)
        if d.check(ciphertext):
            break

Answer 2

所以我对你们所有人的帮助都有所帮助，并且有点改造了这个程序。它有点凌乱，但它的工作原理。代码：

from PyDictionary import PyDictionary
import enchant
MAX_KEY_SIZE = 26
Go='Yes'
dictionary = PyDictionary()
d = enchant.Dict("en_US")
alpha1 = dict(zip("ABCDEFGHIJKLMNOPQRSTUVWXYZ",range(26)))
alpha2 = dict(zip(range(26),"ABCDEFGHIJKLMNOPQRSTUVWXYZ"))
#gets if the user wants to encrypt or decrypt
def getMode():
  while True:
      print('Do you wish to encrypt, decrypt or brute force a message')
      mode = input().lower()
      if mode in 'encrypt e decrypt d bruteforce bf'.split():
         return mode
      else:
         print('Enter either "encrypt" or "e" or "decrypt" or "d" or "bruteforce" or "bf".')
#gets offset value
def getKey(mode):
 key = 0
 if mode[0]=='b':
       pass
 else: 
       while True:
           key = int(input('Enter the offset number (1-%s)' % (MAX_KEY_SIZE)))
           if (key >= 1 and key <= MAX_KEY_SIZE):
              return key
#translates the message
def getTranslatedMessage(mode, message, key):
  ciphertext=''

  if mode[0] == 'd':
        key = -key
        for c in message.upper():
              if c.isalpha():
                    ciphertext += alpha2[ (alpha1[c] + key)]
              else: ciphertext += c
  elif mode[0] =='e':
        for x in message.upper():
              if x.isalpha():
                    ciphertext += alpha2[ (alpha1[x] + key)% (MAX_KEY_SIZE) ]
              else:
                    ciphertext += x
  else:
        brutekey=0
        while True:
              for i in message.upper():
                    ciphertext += alpha2[ (alpha1[i] + brutekey)% (MAX_KEY_SIZE)]
              print(ciphertext)
              if d.check(ciphertext):
                    break
              else:
                    ciphertext=''
                    brutekey=brutekey+1

  return ciphertext
while Go=='yes' or 'Yes' or 'YES' or 'YEs' or 'yeS' :
  mode = getMode()
  message = input("please input your message")
  key = getKey(mode)
  print('Your translated text is:')
  print(getTranslatedMessage(mode, message, key))
  Go=input('Would you like to use the cipher again?')
  if Go in 'yes Yes YES YEs yeS':
        pass
  else:
        print("thank you for using the program")
        break

为caeser密码写蛮力，得到错误

2 个答案: