ROT13 암호 - TECHCODEVIEW.COM - IT 문제 및 솔루션

ROT13 암호(읽기 – 13자리 회전)는 이동이 항상 13인 Ceaser 암호의 특별한 경우입니다.
따라서 모든 문자는 메시지를 암호화하거나 해독하기 위해 13자리 이동됩니다.

그냥 또 하나의 시저 암호라고 생각하셔야 합니다. 이번에는 뭐가 다른데? 차이점은 구현에 있습니다. 접근 방식은 두 개의 별도 Python 사전을 사용하는 것입니다.

첫 번째는 이동된 숫자를 얻기 위해 영어 알파벳의 위치에 따라 다양한 문자를 조회하는 것입니다.
두 번째는 이동된 숫자에 해당하는 문자를 가져오는 것입니다.

구현:

C++

java의 string.replaceall

// CPP program to implement> // ROT13 Caesar Cipher> #include> using> namespace> std;> // Map to lookup the index of alphabets> map <>char>,>int>>dict1;> // Map to lookup alphabets corresponding> // to the index after shift> map <>int>,>char>>dict2;> // Function to create map to lookup> void> create_dict()> {> >for>(>int> i = 1; i <27; i++)> >dict1[>char>(64 + i)] = i;> > >dict2[0] =>'Z'>;> > >for>(>int> i = 1; i <26; i++)> >dict2[i] =>char>(64 + i);> > >return>;> }> // Function to encrypt the string> // according to the shift provided> string encrypt(string message,>int> shift)> {> >string cipher =>''>;> >for>(>int>

i = 0; i   {  // Checking for namespace  if(message[i] != ' ')  {  // looks up the map and  // adds the shift to the index  int num = (dict1[message[i]] + shift) % 26;    // looks up the second map for the  // shifted alphabets and adds them  cipher += dict2[num];  }  else  {  // adds space  cipher += ' ';  }  }  return cipher; } // Function to decrypt the string // according to the shift provided string decrypt(string message, int shift) {  string decipher = '';  for(int i = 0; i   {  // checks for space  if(message[i] != ' ')  {  // looks up the map and  // subtracts the shift to the index  int num = (dict1[message[i]] - shift + 26) % 26;  // looks up the second map for the  // shifted alphabets and adds them  decipher += dict2[num];  }  else  {  // adds space  decipher += ' ';  }  }  return decipher; } // Driver code int main() {  create_dict();    string message = 'GEEKS FOR GEEKS';  int shift = 13;    cout << encrypt(message, shift) << '
';    message = 'TRRXF SBE TRRXF';  shift = 13;    cout << decrypt(message, shift) << '
';    return 0; } // This code is contributed by Sachin Bisht>

자바

지도 자바

// java program for the above approach> import> java.util.*;> public> class> Main {> >// Map to lookup the index of alphabets> >static> Map dict1 =>new> HashMap();> >// Map to lookup alphabets corresponding> >// to the index after shift> >static> Map dict2 =>new> HashMap();> >// Function to create map to lookup> >static> void> create_dict() {> >for>(>int> i =>1>; i <>27>; i++)> >dict1.put((>char>)(>64> + i), i);> >dict2.put(>0>,>'Z'>);> >for>(>int> i =>1>; i <>26>; i++)> >dict2.put(i, (>char>)(>64> + i));> >}> >// Function to encrypt the string> >// according to the shift provided> >static> String encrypt(String message,>int> shift) {> >String cipher =>''>;> >for>(>int> i =>0>

; i   // Checking for namespace  if(message.charAt(i) != ' ') {  // looks up the map and  // adds the shift to the index  int num = (dict1.get(message.charAt(i)) + shift) % 26;  // looks up the second map for the  // shifted alphabets and adds them  cipher += dict2.get(num);  }  else {  // adds space  cipher += ' ';  }  }  return cipher;  }  // Function to decrypt the string  // according to the shift provided  static String decrypt(String message, int shift) {  String decipher = '';  for(int i = 0; i   // checks for space  if(message.charAt(i) != ' ') {  // looks up the map and  // subtracts the shift to the index  int num = (dict1.get(message.charAt(i)) - shift + 26) % 26;  // looks up the second map for the  // shifted alphabets and adds them  decipher += dict2.get(num);  }  else {  // adds space  decipher += ' ';  }  }  return decipher;  }  // Driver code  public static void main(String[] args) {  create_dict();  String message = 'GEEKS FOR GEEKS';  int shift = 13;  System.out.println(encrypt(message, shift));  message = 'TRRXF SBE TRRXF';  shift = 13;  System.out.println(decrypt(message, shift));  } } // This code is contributed by prince>

파이썬3

# Python program to implement> # ROT13 Caesar cipher> '''This script uses dictionaries instead of 'chr()' & 'ord()' function'''> # Dictionary to lookup the index of alphabets> dict1>=> {>'A'> :>1>,>'B'> :>2>,>'C'> :>3>,>'D'> :>4>,>'E'> :>5>,> >'F'> :>6>,>'G'> :>7>,>'H'> :>8>,>'I'> :>9>,>'J'> :>10>,> >'K'> :>11>,>'L'> :>12>,>'M'> :>13>,>'N'> :>14>,>'O'> :>15>,> >'P'> :>16>,>'Q'> :>17>,>'R'> :>18>,>'S'> :>19>,>'T'> :>20>,> >'U'> :>21>,>'V'> :>22>,>'W'> :>23>,>'X'> :>24>,>'Y'> :>25>,>'Z'> :>26>}> # Dictionary to lookup alphabets> # corresponding to the index after shift> dict2>=> {>0> :>'Z'>,>1> :>'A'>,>2> :>'B'>,>3> :>'C'>,>4> :>'D'>,>5> :>'E'>,> >6> :>'F'>,>7> :>'G'>,>8> :>'H'>,>9> :>'I'>,>10> :>'J'>,> >11> :>'K'>,>12> :>'L'>,>13> :>'M'>,>14> :>'N'>,>15> :>'O'>,> >16> :>'P'>,>17> :>'Q'>,>18> :>'R'>,>19> :>'S'>,>20> :>'T'>,> >21> :>'U'>,>22> :>'V'>,>23> :>'W'>,>24> :>'X'>,>25> :>'Y'>}> # Function to encrypt the string> # according to the shift provided> def> encrypt(message, shift):> >cipher>=> ''> >for> letter>in> message:> ># checking for space> >if>(letter !>=> ' '>):> ># looks up the dictionary and> ># adds the shift to the index> >num>=> ( dict1[letter]>+> shift )>%> 26> ># looks up the second dictionary for> ># the shifted alphabets and adds them> >cipher>+>=> dict2[num]> >else>:> ># adds space> >cipher>+>=> ' '> >return> cipher> # Function to decrypt the string> # according to the shift provided> def> decrypt(message, shift):> >decipher>=> ''> >for> letter>in> message:> ># checks for space> >if>(letter !>=> ' '>):> ># looks up the dictionary and> ># subtracts the shift to the index> >num>=> ( dict1[letter]>-> shift>+> 26>)>%> 26> ># looks up the second dictionary for the> ># shifted alphabets and adds them> >decipher>+>=> dict2[num]> >else>:> ># adds space> >decipher>+>=> ' '> >return> decipher> # driver function to run the program> def> main():> ># use 'upper()' function to convert any lowercase characters to uppercase> >message>=> 'GEEKS FOR GEEKS'> >shift>=> 13> >result>=> encrypt(message.upper(), shift)> >print> (result)> >message>=> 'TRRXF SBE TRRXF'> >shift>=> 13> >result>=> decrypt(message.upper(), shift)> >print> (result)> # Executes the main function> if> __name__>=>=> '__main__'>:> >main()>

씨#

using> System;> using> System.Collections;> using> System.Collections.Generic;> using> System.Linq;> // C# program for the above approach> class> HelloWorld {> > >// Map to lookup the index of alphabets> >public> static> Dictionary<>char>,>int>>dict1 =>new> Dictionary<>char>,>int>>();> >// Map to lookup alphabets corresponding> >// to the index after shift> >public> static> Dictionary<>int>,>char>>dict2 =>new> Dictionary<>int>,>char>>();> >// Function to create map to lookup> >public> static> void> create_dict() {> >for>(>int> i = 1; i <27; i++)> >dict1.Add((>char>)(64 + i), i);> >dict2.Add(0,>'Z'>);> >for>(>int> i = 1; i <26; i++)> >dict2.Add(i, (>char>)(64 + i));> >}> >// Function to encrypt the string> >// according to the shift provided> >public> static> string> encrypt(>string> message,>int> shift) {> >string> cipher =>''>;> >for>(>int>

i = 0; i   // Checking for namespace  if(message[i] != ' ') {  // looks up the map and  // adds the shift to the index  int num = (dict1[message[i]] + shift) % 26;  // looks up the second map for the  // shifted alphabets and adds them  cipher += dict2[num];  }  else {  // adds space  cipher += ' ';  }  }  return cipher;  }  // Function to decrypt the string  // according to the shift provided  public static string decrypt(string message, int shift) {  string decipher = '';  for(int i = 0; i   // checks for space  if(message[i] != ' ') {  // looks up the map and  // subtracts the shift to the index  int num = (dict1[message[i]]- shift + 26) % 26;  // looks up the second map for the  // shifted alphabets and adds them  decipher += dict2[num];  }  else {  // adds space  decipher += ' ';  }  }  return decipher;  }      static void Main() {  create_dict();  string message = 'GEEKS FOR GEEKS';  int shift = 13;  Console.WriteLine(encrypt(message, shift));  message = 'TRRXF SBE TRRXF';  shift = 13;  Console.WriteLine(decrypt(message, shift));  } } // The code is contributed by Nidhi goel.>

다음 자바

자바스크립트

// Dictionary to lookup the index of alphabets> const dict1 = {>'A'>: 1,>'B'>: 2,>'C'>: 3,>'D'>: 4,>'E'>: 5,> >'F'>: 6,>'G'>: 7,>'H'>: 8,>'I'>: 9,>'J'>: 10,> >'K'>: 11,>'L'>: 12,>'M'>: 13,>'N'>: 14,>'O'>: 15,> >'P'>: 16,>'Q'>: 17,>'R'>: 18,>'S'>: 19,>'T'>: 20,> >'U'>: 21,>'V'>: 22,>'W'>: 23,>'X'>: 24,>'Y'>: 25,>'Z'>: 26};> // Dictionary to lookup alphabets> // corresponding to the index after shift> const dict2 = {0:>'Z'>, 1:>'A'>, 2:>'B'>, 3:>'C'>, 4:>'D'>, 5:>'E'>,> >6:>'F'>, 7:>'G'>, 8:>'H'>, 9:>'I'>, 10:>'J'>,> >11:>'K'>, 12:>'L'>, 13:>'M'>, 14:>'N'>, 15:>'O'>,> >16:>'P'>, 17:>'Q'>, 18:>'R'>, 19:>'S'>, 20:>'T'>,> >21:>'U'>, 22:>'V'>, 23:>'W'>, 24:>'X'>, 25:>'Y'>};> // Function to encrypt the string> // according to the shift provided> function> encrypt(message, shift) {> >let cipher =>''>;> >for>

(let i = 0; i   const letter = message[i];  // checking for space  if (letter !== ' ') {  // looks up the dictionary and   // adds the shift to the index  const num = (dict1[letter] + shift) % 26;  // looks up the second dictionary for   // the shifted alphabets and adds them  cipher += dict2[num];  } else {  // adds space  cipher += ' ';  }  }  return cipher; } // Function to decrypt the string  // according to the shift provided function decrypt(message, shift) {  let decipher = '';  for (let i = 0; i   const letter = message[i];  // checks for space  if (letter !== ' ') {  // looks up the dictionary and   // subtracts the shift to the index  const num = (dict1[letter] - shift + 26) % 26;  // looks up the second dictionary for the   // shifted alphabets and adds them  decipher += dict2[num];  } else {  // adds space  decipher += ' ';  }  }  return decipher; } // driver function to run the program function main() {  // use 'toUpperCase()' function to convert any lowercase characters to uppercase  let message = 'GEEKS FOR GEEKS';  let shift = 13;  let result = encrypt(message.toUpperCase(), shift);  console.log(result);  message = 'TRRXF SBE TRRXF';  shift = 13;  result = decrypt(message.toUpperCase(), shift);    console.log(result);   } main(); // This code is contributed by adityashatmfh>

strsep

산출

TRRXF SBE TRRXF GEEKS FOR GEEKS>

분석: ROT13 암호는 Caesar 암호의 특별한 경우이므로 그다지 안전하지 않습니다. Caesar 암호는 빈도 분석을 사용하거나 25개의 키를 모두 시도하여 해독할 수 있는 반면, ROT13 암호는 문자를 13자리만 이동하면 해독할 수 있습니다. 그러므로 실용성은 없습니다.

애플리케이션: ROT13은 1980년대 초에 net.jokes 뉴스그룹에서 사용되었습니다.