ROT13 ŠIFRS — TECHCODEVIEW.COM - IT PROBLĒMAS UN RISINĀJUMI

ROT13 šifrs (lasīt kā – pagriezt par 13 vietām) ir īpašs Ceaser šifra gadījums, kurā nobīde vienmēr ir 13.
Tātad katrs burts tiek pārvietots par 13 vietām, lai šifrētu vai atšifrētu ziņojumu.

Jums jādomā, ka tas ir tikai kārtējais ķeizara šifrs kas šoreiz savādāks? Nu atšķirība ir tā īstenošanā. Šī pieeja ir izmantot divas atsevišķas pitonu vārdnīcas.

Vispirms ir jāatrod dažādi burti atbilstoši to vietai angļu alfabētā, lai iegūtu nobīdīto ciparu
Otrais, lai iegūtu burtus, kas atbilst šiem nobīdītajiem cipariem.

Īstenošana:

gb pret mb

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>

kāda kolekcija java

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

fcfs

# 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 =>>Dictionary<>char>,>int>>();> >// Map to lookup alphabets corresponding> >// to the index after shift> >public> static> Dictionary<>int>,>char>>dict2 =>>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.>

Būla valoda c

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>

css pārejas necaurredzamība

Izvade

TRRXF SBE TRRXF GEEKS FOR GEEKS>

Analīze: ROT13 šifrs nav īpaši drošs, jo tas ir tikai īpašs Cēzara šifra gadījums. Cēzara šifru var uzlauzt, izmantojot frekvences analīzi vai vienkārši izmēģinot visas 25 atslēgas, savukārt ROT13 šifru var sabojāt, vienkārši pārvietojot burtus par 13 vietām. Tāpēc tam nav praktiska pielietojuma.

Pielietojums: ROT13 tika izmantots intereškopā net.jokes 80. gadu sākumā.