Hgggjj 2g4c68
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PLAYFAIR CIPHER: Program: #include
using namespace std; typedef struct{ int row; int col; }position; char mat[5][5]; // Global Variable void generateMatrix(string key) { /* to keep tacks of letters that are filled in matrix */ /* flag = 0 -> letter not present in matrix */ /* flag = 1 -> letter present in matrix */ int flag[26] = {0}; int x = 0, y = 0; /* Add all characters present in the key */ for(int i=0; i
{ mat[x][y++] = ch; flag[ch - 'a'] = 1 ; } if(y==5) { x++; y=0; } } } /* function to add filler letter('x') */ string formatMessage(string message) { for(int i=0; i<message.length(); i++) { if(message[i] == ' ') { message = message.replace(i, 1, ""); // remove spaces } if(message[i] == 'j') { message[i] = 'i'; } } for(int i=1; i<message.length(); i+=2) { if(message[i-1] == message[i]) { message = message.insert(i, "x"); } } if(message.length()%2 != 0) { message += "x"; } return message; } /* Returns the position of the character */
position getPosition(char c) { for(int i=0; i<5; i++) { for(int j=0; j<5; j++) { if(c == mat[i][j]) { position p = {i, j}; return p; } } } } string encrypt(string message) { string ctext; for(int i=0; i<message.length(); i+=2) // i is incremented by 2 inorder to group by two two characters { position p1 = getPosition(message[i]); position p2 = getPosition(message[i+1]); int x1 = p1.row; int x2 = p2.row; int y1 = p1.col; int y2 = p2.col; if( x1 == x2 ) { ctext.append(1, mat[x1][(y1+1)%5]); ctext.append(1, mat[x2][(y2+1)%5]); } else if( y1 == y2 ) { ctext.append(1, mat[ (x1+1)%5 ][ y1 ]); ctext.append(1, mat[ (x2+1)%5 ][ y2 ]); } else { ctext.append(1, mat[ x1 ][ y2 ]); ctext.append(1, mat[ x2 ][ y1 ]); } }
return ctext; }
string Decrypt(string message) { string msg; for(int i=0; i<message.length(); i+=2) { position p1 = getPosition(message[i]); position p2 = getPosition(message[i+1]); int x1 = p1.row; int x2 = p2.row; int y1 = p1.col; int y2 = p2.col; if( x1 == x2 ) { msg.append(1, mat[x1][ --y1<0 ? 4: y1 ]); msg.append(1, mat[x2][ --y2<0 ? 4: y2 ]); } else if( y1 == y2 ) { msg.append(1, mat[ --x1<0 ? 4: x1 ][y1]); msg.append(1, mat[ --x2<0 ? 4: x2 ][y2]); } else { msg.append(1, mat[ x1 ][ y2 ]); msg.append(1, mat[ x2 ][ y1 ]); } } return msg; } int main() { int n; // number of keys string plaintext; cout << "Enter message : "; getline(cin, plaintext); cout << "Enter number of keys : ";
cin >> n; cin.get(); string key[n]; for(int i=0; i
Output: Enter message : balloon Enter number of keys : 2 Enter key 1 : monarchy Key 1 Matrix: m o n a r c h y b d e f g i k l p q s t u v w x z Actual Message : balloon Formatted Message : balxloon Encrypted Message : ibsupmna Decrypted Message : balxloon
Enter key 2 : playfair Key 2 Matrix: p l a y f i r b c d e g h k m n o q s t u v w x z Actual Message : balloon Formatted Message : balxloon Encrypted Message : hbyvrvqo Decrypted Message : balxloon
{ mat[x][y++] = ch; flag[ch - 'a'] = 1 ; } if(y==5) { x++; y=0; } } } /* function to add filler letter('x') */ string formatMessage(string message) { for(int i=0; i<message.length(); i++) { if(message[i] == ' ') { message = message.replace(i, 1, ""); // remove spaces } if(message[i] == 'j') { message[i] = 'i'; } } for(int i=1; i<message.length(); i+=2) { if(message[i-1] == message[i]) { message = message.insert(i, "x"); } } if(message.length()%2 != 0) { message += "x"; } return message; } /* Returns the position of the character */
position getPosition(char c) { for(int i=0; i<5; i++) { for(int j=0; j<5; j++) { if(c == mat[i][j]) { position p = {i, j}; return p; } } } } string encrypt(string message) { string ctext; for(int i=0; i<message.length(); i+=2) // i is incremented by 2 inorder to group by two two characters { position p1 = getPosition(message[i]); position p2 = getPosition(message[i+1]); int x1 = p1.row; int x2 = p2.row; int y1 = p1.col; int y2 = p2.col; if( x1 == x2 ) { ctext.append(1, mat[x1][(y1+1)%5]); ctext.append(1, mat[x2][(y2+1)%5]); } else if( y1 == y2 ) { ctext.append(1, mat[ (x1+1)%5 ][ y1 ]); ctext.append(1, mat[ (x2+1)%5 ][ y2 ]); } else { ctext.append(1, mat[ x1 ][ y2 ]); ctext.append(1, mat[ x2 ][ y1 ]); } }
return ctext; }
string Decrypt(string message) { string msg; for(int i=0; i<message.length(); i+=2) { position p1 = getPosition(message[i]); position p2 = getPosition(message[i+1]); int x1 = p1.row; int x2 = p2.row; int y1 = p1.col; int y2 = p2.col; if( x1 == x2 ) { msg.append(1, mat[x1][ --y1<0 ? 4: y1 ]); msg.append(1, mat[x2][ --y2<0 ? 4: y2 ]); } else if( y1 == y2 ) { msg.append(1, mat[ --x1<0 ? 4: x1 ][y1]); msg.append(1, mat[ --x2<0 ? 4: x2 ][y2]); } else { msg.append(1, mat[ x1 ][ y2 ]); msg.append(1, mat[ x2 ][ y1 ]); } } return msg; } int main() { int n; // number of keys string plaintext; cout << "Enter message : "; getline(cin, plaintext); cout << "Enter number of keys : ";
cin >> n; cin.get(); string key[n]; for(int i=0; i
Output: Enter message : balloon Enter number of keys : 2 Enter key 1 : monarchy Key 1 Matrix: m o n a r c h y b d e f g i k l p q s t u v w x z Actual Message : balloon Formatted Message : balxloon Encrypted Message : ibsupmna Decrypted Message : balxloon
Enter key 2 : playfair Key 2 Matrix: p l a y f i r b c d e g h k m n o q s t u v w x z Actual Message : balloon Formatted Message : balxloon Encrypted Message : hbyvrvqo Decrypted Message : balxloon
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