CIFRUL ROT13 - TECHCODEVIEW.COM - PROBLEME ȘI SOLUȚII IT

Cifrul ROT13 (citește ca – rotește cu 13 locuri) este un caz special al cifrului Ceaser în care schimbarea este întotdeauna 13.
Deci, fiecare literă este mutată în 13 locuri pentru a cripta sau a decripta mesajul.

Trebuie să te gândești că este doar un alt cifru caesar, așa că ce este diferit de data asta? Ei bine, diferența este în implementarea sa. Abordarea este de a folosi două dicționare python separate.

Primul care caută diferitele litere în funcție de locul lor în alfabetul englez pentru a obține numărul deplasat
Al doilea pentru a obține literele care corespund numerelor mutate.

Implementare:

C++

// 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>

algoritmul „bancherului”

Java

// 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>

Python3

egalitatea obiectelor în java

# 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()>

C#

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.>

Javascript

// 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>

Ieșire

mamta kulkarni actor

TRRXF SBE TRRXF GEEKS FOR GEEKS>

Analiză: Cifrul ROT13 nu este foarte sigur deoarece este doar un caz special al cifrului Caesar. Cifrul Caesar poate fi rupt fie prin analiza de frecvență, fie prin încercarea tuturor celor 25 de chei, în timp ce cifrul ROT13 poate fi rupt prin deplasarea literelor în 13 locuri. Prin urmare, nu are nicio utilizare practică.

Aplicație: ROT13 a fost folosit în grupul de știri net.jokes la începutul anilor 1980.