열형 전치 암호
일반 텍스트 메시지와 숫자 키가 주어지면 열형 전치 암호를 사용하여 주어진 텍스트를 암호/해독합니다. 열형 전치 암호는 다음과 같은 전치 암호의 한 형태입니다. 레일 펜스 암호 . 열형 전치에는 일반 텍스트를 행으로 쓴 다음 열의 암호문을 하나씩 읽는 작업이 포함됩니다.
예:
Encryption Input : Geeks for Geeks Key = HACK Output : e kefGsGsrekoe_ Decryption Input : e kefGsGsrekoe_ Key = HACK Output : Geeks for Geeks Encryption Input : Geeks on work Key = HACK Output : e w_eoo_Gs kknr_ Decryption Input : e w_eoo_Gs kknr_ Key = HACK Output : Geeks on work암호화
전치암호에서는 알파벳의 순서를 재배열하여 암호문을 얻는다.
- 메시지는 고정된 길이의 행에 기록된 다음 열별로 다시 읽혀지고 열은 스크램블된 순서로 선택됩니다.
- 행 너비와 열 순열은 일반적으로 키워드로 정의됩니다.
- 예를 들어 HACK이라는 단어의 길이는 4이고(따라서 행의 길이는 4임) 순열은 키워드 문자의 알파벳 순서로 정의됩니다. 이 경우 순서는 '3 1 2 4'입니다.
- 여유 공간은 널(null)로 채워지거나 공백으로 남겨지거나 문자(예: _)로 배치됩니다.
- 마지막으로 메시지는 키워드에 지정된 순서대로 열에서 읽혀집니다.
암호 해독
C++
- 이를 해독하려면 수신자는 메시지 길이를 키 길이로 나누어 열 길이를 계산해야 합니다.
- 그런 다음 다시 열에 메시지를 작성한 다음 키워드를 다시 고쳐 열의 순서를 다시 지정합니다.
Java// CPP program for illustrating // Columnar Transposition Cipher #includeusing namespace std ; // Encription function string Encryption ( int no_rows int len_key int len_msg string msg int col_val []) { int x = 0 ; char enc_mat [ no_rows + 1 ][ len_key ]; // creating the matrix for ( int i = 0 ; i < no_rows + 1 ; i ++ ) { for ( int j = 0 ; j < len_key ; j ++ ) { // initializes the positions with '_' after the // end of message if ( x >= len_msg ) { enc_mat [ i ][ j ] = '_' ; } else { enc_mat [ i ][ j ] = msg [ x ]; } x ++ ; } } int t = 1 ; string cipher = '' ; // finding the cipher text according to the value of // col_val matrix while ( t <= len_key ) { for ( int i = 0 ; i < len_key ; i ++ ) { int k = col_val [ i ]; if ( k == t ) { for ( int j = 0 ; j < no_rows + 1 ; j ++ ) { cipher += enc_mat [ j ][ i ]; } t ++ ; } } } return cipher ; } // decryption function string Decryption ( int no_rows int len_key string cipher int col_val []) { char dec_mat [ no_rows + 1 ][ len_key ]; int x = 0 t = 1 ; // rearrange the matrix according to the col_val while ( t <= len_key ) { for ( int i = 0 ; i < len_key ; i ++ ) { int k = col_val [ i ]; if ( k == t ) { for ( int j = 0 ; j < no_rows + 1 ; j ++ ) { dec_mat [ j ][ i ] = cipher [ x ]; x ++ ; } t ++ ; } } } string message = '' ; for ( int i = 0 ; i < no_rows + 1 ; i ++ ) { for ( int j = 0 ; j < len_key ; j ++ ) { // replacing the '_' with space if ( dec_mat [ i ][ j ] == '_' ) { dec_mat [ i ][ j ] = ' ' ; } message += dec_mat [ i ][ j ]; } } return message ; } int main () { // message string msg = 'Geeks for Geeks' ; // key string key = 'HACK' ; int len_key = key . length (); int len_msg = msg . length (); int val = 1 count = 0 ind ; int col_val [ len_key ]; // intializing col_val matrix with 0 memset ( col_val 0 sizeof ( col_val )); // numbering the key alphabets according to its ACII // value while ( count < len_key ) { int min = 999 ; for ( int i = 0 ; i < len_key ; i ++ ) { if (( min > int ( key [ i ])) && ( col_val [ i ] == 0 )) { min = int ( key [ i ]); ind = i ; } } col_val [ ind ] = val ; count ++ ; val ++ ; } int no_rows = len_msg / len_key ; // encrypted text string cipher_text = ' ' ; cipher_text = Encryption ( no_rows len_key len_msg msg col_val ); cout < < 'Encrypted Message : ' < < cipher_text < < endl ; // decrypted text string original_msg = ' ' ; original_msg = Decryption ( no_rows len_key cipher_text col_val ); cout < < 'Decrypted Message : ' < < original_msg < < endl ; } // This code is contributed by Suchita Gond Pythonimport java.util.* ; public class ColumnarTranspositionCipher { // Key for Columnar Transposition static final String key = 'HACK' ; static Map < Character Integer > keyMap = new HashMap <> (); static void setPermutationOrder () { // Add the permutation order into the map for ( int i = 0 ; i < key . length (); i ++ ) { keyMap . put ( key . charAt ( i ) i ); } } // Encryption static String encryptMessage ( String msg ) { int row col ; StringBuilder cipher = new StringBuilder (); /* Calculate the number of columns in the matrix */ col = key . length (); /* Calculate the maximum number of rows in the matrix */ row = ( int ) Math . ceil (( double ) msg . length () / col ); char [][] matrix = new char [ row ][ col ] ; for ( int i = 0 k = 0 ; i < row ; i ++ ) { for ( int j = 0 ; j < col ; ) { if ( k < msg . length ()) { char ch = msg . charAt ( k ); if ( Character . isLetter ( ch ) || ch == ' ' ) { matrix [ i ][ j ] = ch ; j ++ ; } k ++ ; } else { /* Add padding character '_' */ matrix [ i ][ j ] = '_' ; j ++ ; } } } for ( Map . Entry < Character Integer > entry : keyMap . entrySet ()) { int columnIndex = entry . getValue (); // Get the cipher text from the matrix column-wise using the permuted key for ( int i = 0 ; i < row ; i ++ ) { if ( Character . isLetter ( matrix [ i ][ columnIndex ] ) || matrix [ i ][ columnIndex ] == ' ' || matrix [ i ][ columnIndex ] == '_' ) { cipher . append ( matrix [ i ][ columnIndex ] ); } } } return cipher . toString (); } // Decryption static String decryptMessage ( String cipher ) { /* Calculate the number of columns for the cipher matrix */ int col = key . length (); int row = ( int ) Math . ceil (( double ) cipher . length () / col ); char [][] cipherMat = new char [ row ][ col ] ; /* Add characters into the matrix column-wise */ int k = 0 ; for ( int j = 0 ; j < col ; j ++ ) { for ( int i = 0 ; i < row ; i ++ ) { cipherMat [ i ][ j ] = cipher . charAt ( k ); k ++ ; } } /* Update the order of the key for decryption */ int index = 0 ; for ( Map . Entry < Character Integer > entry : keyMap . entrySet ()) { entry . setValue ( index ++ ); } /* Arrange the matrix column-wise according to the permutation order */ char [][] decCipher = new char [ row ][ col ] ; for ( int l = 0 ; l < key . length (); l ++ ) { int columnIndex = keyMap . get ( key . charAt ( l )); for ( int i = 0 ; i < row ; i ++ ) { decCipher [ i ][ l ] = cipherMat [ i ][ columnIndex ] ; } } /* Get the message using the matrix */ StringBuilder msg = new StringBuilder (); for ( int i = 0 ; i < row ; i ++ ) { for ( int j = 0 ; j < col ; j ++ ) { if ( decCipher [ i ][ j ] != '_' ) { msg . append ( decCipher [ i ][ j ] ); } } } return msg . toString (); } public static void main ( String [] args ) { /* Message */ String msg = 'Geeks for Geeks' ; setPermutationOrder (); // Calling encryption function String cipher = encryptMessage ( msg ); System . out . println ( 'Encrypted Message: ' + cipher ); // Calling Decryption function System . out . println ( 'Decrypted Message: ' + decryptMessage ( cipher )); } }C## Python3 implementation of # Columnar Transposition import math key = 'HACK' # Encryption def encryptMessage ( msg ): cipher = '' # track key indices k_indx = 0 msg_len = float ( len ( msg )) msg_lst = list ( msg ) key_lst = sorted ( list ( key )) # calculate column of the matrix col = len ( key ) # calculate maximum row of the matrix row = int ( math . ceil ( msg_len / col )) # add the padding character '_' in empty # the empty cell of the matix fill_null = int (( row * col ) - msg_len ) msg_lst . extend ( '_' * fill_null ) # create Matrix and insert message and # padding characters row-wise matrix = [ msg_lst [ i : i + col ] for i in range ( 0 len ( msg_lst ) col )] # read matrix column-wise using key for _ in range ( col ): curr_idx = key . index ( key_lst [ k_indx ]) cipher += '' . join ([ row [ curr_idx ] for row in matrix ]) k_indx += 1 return cipher # Decryption def decryptMessage ( cipher ): msg = '' # track key indices k_indx = 0 # track msg indices msg_indx = 0 msg_len = float ( len ( cipher )) msg_lst = list ( cipher ) # calculate column of the matrix col = len ( key ) # calculate maximum row of the matrix row = int ( math . ceil ( msg_len / col )) # convert key into list and sort # alphabetically so we can access # each character by its alphabetical position. key_lst = sorted ( list ( key )) # create an empty matrix to # store deciphered message dec_cipher = [] for _ in range ( row ): dec_cipher += [[ None ] * col ] # Arrange the matrix column wise according # to permutation order by adding into new matrix for _ in range ( col ): curr_idx = key . index ( key_lst [ k_indx ]) for j in range ( row ): dec_cipher [ j ][ curr_idx ] = msg_lst [ msg_indx ] msg_indx += 1 k_indx += 1 # convert decrypted msg matrix into a string try : msg = '' . join ( sum ( dec_cipher [])) except TypeError : raise TypeError ( 'This program cannot' 'handle repeating words.' ) null_count = msg . count ( '_' ) if null_count > 0 : return msg [: - null_count ] return msg # Driver Code msg = 'Geeks for Geeks' cipher = encryptMessage ( msg ) print ( 'Encrypted Message: {} ' . format ( cipher )) print ( 'Decryped Message: {} ' . format ( decryptMessage ( cipher ))) # This code is contributed by Aditya KJavaScriptusing System ; using System.Collections.Generic ; public class ColumnarTranspositionCipher { // Key for Columnar Transposition static readonly string key = 'HACK' ; static Dictionary < char int > keyMap = new Dictionary < char int > (); static void SetPermutationOrder () { // Add the permutation order into the dictionary for ( int i = 0 ; i < key . Length ; i ++ ) { keyMap [ key [ i ]] = i ; } } // Encryption static string EncryptMessage ( string msg ) { int row col ; System . Text . StringBuilder cipher = new System . Text . StringBuilder (); /* Calculate the number of columns in the matrix */ col = key . Length ; /* Calculate the maximum number of rows in the * matrix */ row = ( int ) Math . Ceiling (( double ) msg . Length / col ); char [ ] matrix = new char [ row col ]; for ( int i = 0 k = 0 ; i < row ; i ++ ) { for ( int j = 0 ; j < col ;) { if ( k < msg . Length ) { char ch = msg [ k ]; if ( char . IsLetter ( ch ) || ch == ' ' ) { matrix [ i j ] = ch ; j ++ ; } k ++ ; } else { /* Add padding character '_' */ matrix [ i j ] = '_' ; j ++ ; } } } foreach ( var entry in new Dictionary < char int > ( keyMap )) { int columnIndex = entry . Value ; // Get the cipher text from the matrix // column-wise using the permuted key for ( int i = 0 ; i < row ; i ++ ) { if ( char . IsLetter ( matrix [ i columnIndex ]) || matrix [ i columnIndex ] == ' ' || matrix [ i columnIndex ] == '_' ) { cipher . Append ( matrix [ i columnIndex ]); } } } return cipher . ToString (); } // Decryption static string DecryptMessage ( string cipher ) { /* Calculate the number of columns for the cipher * matrix */ int col = key . Length ; int row = ( int ) Math . Ceiling (( double ) cipher . Length / col ); char [ ] cipherMat = new char [ row col ]; /* Add characters into the matrix column-wise */ int k = 0 ; for ( int j = 0 ; j < col ; j ++ ) { for ( int i = 0 ; i < row ; i ++ ) { cipherMat [ i j ] = cipher [ k ]; k ++ ; } } /* Update the order of the key for decryption */ int index = 0 ; foreach ( var entry in new Dictionary < char int > ( keyMap )) { keyMap [ entry . Key ] = index ++ ; } /* Arrange the matrix column-wise according to the * permutation order */ char [ ] decCipher = new char [ row col ]; foreach ( var entry in keyMap ) { int columnIndex = entry . Value ; for ( int i = 0 ; i < row ; i ++ ) { decCipher [ i columnIndex ] = cipherMat [ i columnIndex ]; } } /* Get the message using the matrix */ System . Text . StringBuilder msg = new System . Text . StringBuilder (); for ( int i = 0 ; i < row ; i ++ ) { for ( int j = 0 ; j < col ; j ++ ) { if ( decCipher [ i j ] != '_' ) { msg . Append ( decCipher [ i j ]); } } } return msg . ToString (); } public static void Main ( string [] args ) { /* Message */ string msg = 'Geeks for Geeks' ; SetPermutationOrder (); // Calling encryption function string cipher = EncryptMessage ( msg ); Console . WriteLine ( 'Encrypted Message: ' + cipher ); // Calling Decryption function Console . WriteLine ( 'Decrypted Message: ' + DecryptMessage ( cipher )); } }
산출Encrypted Message : e kefGsGsrekoe_ Decrypted Message : Geeks for Geeks퀴즈 만들기
