Playfair cipher
Implement a Playfair cipher for encryption and decryption.
The user must be able to choose J = I or no Q in the alphabet.
The output of the encrypted and decrypted message must be in capitalized digraphs, separated by spaces.
Output example: HI DE TH EG OL DI NT HE TR EX ES TU MP.
C++
<lang cpp>#include <iostream>
- include <string>
using namespace std;
class playfair { public:
void doIt( string k, string t, bool ij, bool e ) {
createGrid( k, ij ); getTextReady( t, ij, e ); if( e ) doIt( 1 ); else doIt( -1 ); display();
}
private:
void doIt( int dir ) {
int a, b, c, d; string ntxt; for( string::const_iterator ti = _txt.begin(); ti != _txt.end(); ti++ ) { if( getCharPos( *ti++, a, b ) ) if( getCharPos( *ti, c, d ) ) { if( a == c ) { ntxt += getChar( a, b + dir ); ntxt += getChar( c, d + dir ); } else if( b == d ){ ntxt += getChar( a + dir, b ); ntxt += getChar( c + dir, d ); } else { ntxt += getChar( c, b ); ntxt += getChar( a, d ); } } } _txt = ntxt;
}
void display() {
cout << "\n\n OUTPUT:\n=========" << endl; string::iterator si = _txt.begin(); int cnt = 0; while( si != _txt.end() ) { cout << *si; si++; cout << *si << " "; si++; if( ++cnt >= 26 ) cout << endl, cnt = 0; } cout << endl << endl;
}
char getChar( int a, int b ) {
return _m[ (b + 5) % 5 ][ (a + 5) % 5 ];
}
bool getCharPos( char l, int &a, int &b ) {
for( int y = 0; y < 5; y++ ) for( int x = 0; x < 5; x++ ) if( _m[y][x] == l ) { a = x; b = y; return true; }
return false;
}
void getTextReady( string t, bool ij, bool e ) {
for( string::iterator si = t.begin(); si != t.end(); si++ ) { *si = toupper( *si ); if( *si < 65 || *si > 90 ) continue; if( *si == 'J' && ij ) *si = 'I'; else if( *si == 'Q' && !ij ) continue; _txt += *si; } if( e ) { string ntxt = ""; size_t len = _txt.length(); for( size_t x = 0; x < len; x += 2 ) { ntxt += _txt[x]; if( x + 1 < len ) { if( _txt[x] == _txt[x + 1] ) ntxt += 'X'; ntxt += _txt[x + 1]; } } _txt = ntxt; } if( _txt.length() & 1 ) _txt += 'X';
}
void createGrid( string k, bool ij ) {
if( k.length() < 1 ) k = "KEYWORD"; k += "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; string nk = ""; for( string::iterator si = k.begin(); si != k.end(); si++ ) { *si = toupper( *si ); if( *si < 65 || *si > 90 ) continue; if( ( *si == 'J' && ij ) || ( *si == 'Q' && !ij ) )continue; if( nk.find( *si ) == -1 ) nk += *si; } copy( nk.begin(), nk.end(), &_m[0][0] );
}
string _txt; char _m[5][5];
};
int main( int argc, char* argv[] ) {
string key, i, txt; bool ij, e; cout << "(E)ncode or (D)ecode? "; getline( cin, i ); e = ( i[0] == 'e' || i[0] == 'E' ); cout << "Enter a en/decryption key: "; getline( cin, key ); cout << "I <-> J (Y/N): "; getline( cin, i ); ij = ( i[0] == 'y' || i[0] == 'Y' ); cout << "Enter the text: "; getline( cin, txt ); playfair pf; pf.doIt( key, txt, ij, e ); return system( "pause" );
}</lang>
- Output:
(E)ncode or (D)ecode? e Enter a en/decryption key: playfair example I <-> J (Y/N): y Enter the text: Hide the gold in the tree stump
OUTPUT: ========= BM OD ZB XD NA BE KU DM UI XM MO UV IF
(E)ncode or (D)ecode? d Enter a en/decryption key: playfair example I <-> J (Y/N): y Enter the text: BMODZBXDNABEKUDMUIXMMOUVIFOUTPUT: ========= HI DE TH EG OL DI NT HE TR EX ES TU MP
D
<lang d>import std.stdio, std.array, std.algorithm, std.range, std.ascii,
std.conv, std.string, std.regex, std.typecons;
string unique(in string s) pure nothrow @safe {
string result; foreach (immutable char c; s) if (!result.representation.canFind(c)) // Assumes ASCII string. result ~= c; return result;
}
struct Playfair {
string from, to; string[string] enc, dec;
this(in string key, in string from_ = "J", in string to_ = null) pure /*nothrow @safe*/ { this.from = from_; if (to_.empty) this.to = (from_ == "J") ? "I" : "";
immutable m = _canonicalize(key ~ uppercase) .unique .chunks(5) .map!text .array; auto I5 = 5.iota;
foreach (immutable R; m) foreach (immutable i, immutable j; cartesianProduct(I5, I5)) if (i != j) enc[[R[i], R[j]]] = [R[(i + 1) % 5], R[(j+1) % 5]];
foreach (immutable r; I5) { immutable c = m.transversal(r).array; foreach (immutable i, immutable j; cartesianProduct(I5, I5)) if (i != j) enc[[c[i], c[j]]] = [c[(i + 1) % 5], c[(j+1) % 5]]; }
foreach (i1, j1, i2, j2; cartesianProduct(I5, I5, I5, I5)) if (i1 != i2 && j1 != j2) enc[[m[i1][j1], m[i2][j2]]] = [m[i1][j2], m[i2][j1]];
dec = enc.byKeyValue.map!(t => tuple(t.value, t.key)).assocArray; }
private string _canonicalize(in string s) const pure @safe { return s.toUpper.removechars("^A-Z").replace(from, to); }
string encode(in string s) const /*pure @safe*/ { return _canonicalize(s) .matchAll(r"(.)(?:(?!\1)(.))?") .map!(m => enc[m[0].leftJustify(2, 'X')]) .join(' '); }
string decode(in string s) const pure @safe { return _canonicalize(s).chunks(2).map!(p => dec[p.text]).join(' '); }
}
void main() /*@safe*/ {
/*immutable*/ const pf = Playfair("Playfair example"); immutable orig = "Hide the gold in...the TREESTUMP!!!"; writeln("Original: ", orig); immutable enc = pf.encode(orig); writeln(" Encoded: ", enc); writeln(" Decoded: ", pf.decode(enc));
}</lang>
- Output:
Original: Hide the gold in...the TREESTUMP!!! Encoded: BM OD ZB XD NA BE KU DM UI XM MO UV IF Decoded: HI DE TH EG OL DI NT HE TR EX ES TU MP
FreeBASIC
<lang freebasic>' FB 1.05.0 Win64
Enum PlayFairOption
noQ iEqualsJ
End Enum
Dim Shared pfo As PlayFairOption set this before calling buildTable Dim Shared table(1 To 5, 1 To 5) As UInteger
Sub buildTable(keyword As String)
Dim used(1 To 26) As Boolean all false by default If pfo = noQ Then used(17) = True Else used(10) = True End If Dim As String alphabet = UCase(keyword) + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" Dim As UInteger i = 1, j = 1, k Dim As Integer c For k = 0 To Len(alphabet) - 1 c = alphabet[k] - 64 If c < 1 OrElse c > 26 Then Continue For If Not used(c) Then table(i, j) = c used(c) = True j += 1 If j = 6 Then i += 1 If i = 6 Then Return table has been filled j = 1 End If End If Next k
End Sub
Function getCleanText(plainText As String) As String
plainText = UCase(plainText) ensure everything is upper case ' get rid of any non-letters and insert X between duplicate letters Dim As String cleanText = "", prevChar = "", nextChar For i As UInteger = 1 To Len(plainText) nextChar = Mid(plainText, i, 1) ' It appears that Q should be omitted altogether if noQ option is specified - we assume so anyway If nextChar < "A" OrElse nextChar > "Z" OrElse (nextChar = "Q" AndAlso pfo = noQ) Then Continue For ' If iEqualsJ option specified, replace J with I If nextChar = "J" AndAlso pfo = iEqualsJ Then nextChar = "I" If nextChar <> prevChar Then cleanText += nextChar Else cleanText += "X" + nextChar End If prevChar = nextChar Next If Len(cleanText) Mod 2 = 1 Then dangling letter at end so add another letter to complete digram If Right(cleanText, 1) <> "X" Then cleanText += "X" Else cleanText += "Z" End If End If Return cleanText
End Function
Sub findChar(c As uInteger, ByRef row As UInteger, ByRef col As UInteger)
For i As UInteger = 1 To 5 For j As UInteger = 1 To 5 If table(i, j) = c Then row = i col = j Return End If Next j Next i
End Sub
Function encodePlayfair(plainText As String) As String
Dim As String cleanText = getCleanText(plainText) Dim As String digram, cipherDigram, cipherText = "" Dim As UInteger length = Len(cleanText) Dim As UInteger char1, char2, row1, col1, row2, col2 For i As UInteger = 1 To length Step 2 digram = Mid(cleanText, i, 2) char1 = digram[0] - 64 char2 = digram[1] - 64 findChar char1, row1, col1 findChar char2, row2, col2 If row1 = row2 Then cipherDigram = Chr(table(row1, col1 Mod 5 + 1) + 64) cipherDigram += Chr(table(row2, col2 Mod 5 + 1) + 64) ElseIf col1 = col2 Then cipherDigram = Chr(table(row1 Mod 5 + 1, col1) + 64) cipherDigram += Chr(table(row2 Mod 5 + 1, col2) + 64) Else cipherDigram = Chr(table(row1, col2) + 64) cipherDigram += Chr(table(row2, col1) + 64) End If cipherText += cipherDigram If i < length Then cipherText += " " Next i Return cipherText
End Function
Function decodePlayfair(cipherText As String) As String
Dim As String digram, cipherDigram, decodedText = "" Dim As UInteger length = Len(cipherText) Dim As UInteger char1, char2, row1, col1, row2, col2 For i As UInteger = 1 To length Step 3 cipherText will include spaces so we need to skip them cipherDigram = Mid(cipherText, i, 2) char1 = cipherDigram[0] - 64 char2 = cipherDigram[1] - 64 findChar char1, row1, col1 findChar char2, row2, col2 If row1 = row2 Then digram = Chr(table(row1, IIf(col1 > 1, col1 - 1, 5)) + 64) digram += Chr(table(row2, IIf(col2 > 1, col2 - 1, 5)) + 64) ElseIf col1 = col2 Then digram = Chr(table(IIf(row1 > 1, row1 - 1, 5), col1) + 64) digram += Chr(table(IIf(row2 > 1, row2 - 1, 5), col2) + 64) Else digram = Chr(table(row1, col2) + 64) digram += Chr(table(row2, col1) + 64) End If decodedText += digram If i < length Then decodedText += " " Next i Return decodedText
End Function
Dim As String keyword, ignoreQ, plainText, encodedText, decodedText Line Input "Enter Playfair keyword : "; keyword
Do
Line Input "Ignore Q when buiding table y/n : "; ignoreQ ignoreQ = LCase(ignoreQ)
Loop Until ignoreQ = "y" Or ignoreQ = "n"
pfo = IIf(ignoreQ = "y", noQ, iEqualsJ) buildTable(keyword) Print "The table to be used is : " : Print For i As UInteger = 1 To 5
For j As UInteger = 1 To 5 Print Chr(table(i, j) + 64); " "; Next j Print
Next i
Print Line Input "Enter plain text : "; plainText Print encodedText = encodePlayfair(plainText) Print "Encoded text is : "; encodedText decodedText = decodePlayFair(encodedText) Print "Decoded text is : "; decodedText Print Print "Press any key to quit" Sleep</lang> Sample input/output:
- Output:
Enter Playfair keyword : ? Playfair example Ignore Q when buiding table y/n : ? n The table to be used is : P L A Y F I R E X M B C D G H K N O Q S T U V W Z Enter plain text : ? Hide the gold in...the TREESTUMP!!!! Encoded text is : BM OD ZB XD NA BE KU DM UI XM MO UV IF Decoded text is : HI DE TH EG OL DI NT HE TR EX ES TU MP
Haskell
<lang haskell> import Control.Monad (guard) import Data.Array (Array, assocs, elems, listArray, (!)) import Data.Char (toUpper) import Data.List (nub, (\\)) import Data.List.Split (chunksOf) import Data.Maybe (listToMaybe) import Data.String.Utils (replace)
type Square a = Array (Int, Int) a
-- | Turns a list into an n*m-array. array2D ::
(Int, Int) -- ^ n * m -> [e] -> Square e
array2D maxCoord = listArray ((1, 1), maxCoord)
-- | Generates a playfair table starting with the specified string. -- -- >>> makeTable "hello" -- "HELOABCDFGIKMNPQRSTUVWXYZ" makeTable :: String -> String makeTable k = nub key ++ (alpha \\ key)
where alpha = ['A' .. 'Z'] \\ "J" key = map toUpper =<< words k
-- | Turns a playfair table into a 5*5 alphabet square. makeSquare :: [a] -> Square a makeSquare = array2D (5, 5)
-- | Displays a playfair square, formatted as a square. showSquare :: Square Char -> String showSquare d = unlines $ chunksOf 5 (elems d)
-- | Given a value and an association list of x-coordinate * y-coordinate * value, returns the coordinates getIndex' :: (Eq a) => a -> [((Int, Int), a)] -> Maybe (Int, Int) getIndex' el = fmap fst . listToMaybe . filter ((== el) . snd)
encodePair, decodePair :: Eq a => Square a -> (a, a) -> Maybe (a, a) encodePair = pairHelper (\x -> if x == 5 then 1 else x + 1) decodePair = pairHelper (\x -> if x == 1 then 5 else x - 1)
pairHelper :: (Eq t)
=> (Int -> Int) -- ^ a function used for wrapping around the square -> Square t -- ^ a playfair square -> (t, t) -- ^ two characters -> Maybe (t, t) -- ^ the two resulting/encoded characters
pairHelper adjust sqr (c1, c2) =
do let ps = assocs sqr -- assigns an association list of (x-coord * y-coord) * value to ps (x1, y1) <- getIndex' c1 ps (x2, y2) <- getIndex' c2 ps -- returns the coordinates of two values in the square -- these will later be swapped guard $ c1 /= c2 -- the characters (and coordinates) cannot be the same let get x = sqr ! x -- a small utility function for extracting a value from the square Just $ -- wrap the coordinates around and find the encrypted characters case () of () | y1 == y2 -> (get (adjust x1, y1), get (adjust x2, y2)) | x1 == x2 -> (get (x1, adjust y1), get (x2, adjust y2)) | otherwise -> (get (x1, y2), get (x2, y1))
-- | Turns two characters into a tuple. parsePair :: String -> [(Char, Char)] parsePair = fmap (\[x, y] -> (x, y)) . words . fmap toUpper
-- | Turns a tuple of two characters into a string. unparsePair :: [(Char, Char)] -> String unparsePair = unwords . fmap (\(x, y) -> [x, y])
codeHelper :: (Square Char -> (Char, Char) -> Maybe (Char, Char))
-> String -> String -> Maybe String
codeHelper subs key =
fmap unparsePair . mapM (subs (makeSquare $ makeTable key)) . parsePair
playfair, unplayfair :: String -> String -> Maybe String playfair key = codeHelper encodePair key . formatEncode unplayfair = codeHelper decodePair
formatEncode :: String -> String formatEncode =
map toUpper . unwords . map (\[x, y] -> if x == y then [x, 'x'] else [x, y]) . chunksOf 2 . replace "j" "i" . concatMap adjustLength . words . filter (\n -> n `elem` (['A'..'Z'] ++ ['a'..'z'])) where adjustLength str | odd (length str) = str ++ "x" | otherwise = str
</lang>
>>> playfair "playfair example" "hide the gold in the tree stump" Just "BM OD ZB XD NA BE KU DM UI XM KZ ZR YI" >>> unplayfair "playfair example" "BM OD ZB XD NA BE KU DM UI XM KZ ZR YI" Just "HI DE TH EG OL DI NT HE TR EX ST UM PX"
J
Rather than implement two versions of the rules, one for encrypt, one for decrypt, let's just make a lookup table (mapping character pairs to character pairs). To decrypt we can look up in the other direction.
Implementation:
<lang J>choose=:3 :0
sel=. 'Q'e.y alph=:(sel{'JQ')-.~a.{~65+i.26 norm=: alph restrict('I' I.@:=&'J'@]} ])`(-.&'Q')@.sel@toupper
) restrict=: ] -. -.~ choose 'Q'
setkey=:3 :0
key=. ~.norm y,alph ref=: ,/2{."1 ~."1 (,"0/~alph),"1 norm 'XQV' mode=. #.=/"2 inds=.5 5#:key i.ref inds0=. (0 3,:2 1)&{@,"2 inds inds1=.5|1 0+"1 inds NB. same column inds2=.5|0 1+"1 inds NB. same row alt=:key{~5 #.mode{"_1 inds0,"2 3 inds1,:"2 inds2 i.0 0
)
pairs=: 3 :0
2{."1 -.&' '"1 ~."1 (_2]\ norm y),"1 'XQV'
)
encrypt=:3 :0
,alt{~ref i. pairs y
)
decrypt=:3 :0
,ref{~alt i. pairs y
)</lang>
Example use:
<lang J> choose 'IJ'
setkey 'playfair example' encrypt 'Hide the gold in the tree stump'
BMODZBXDNABEKUDMUIXMKZZRYI
decrypt 'BMODZBXDNABEKUDMUIXMKZZRYI'
HIDETHEGOLDINTHETREXSTUMPX</lang>
Java
<lang java>import java.awt.Point; import java.util.Scanner;
public class PlayfairCipher {
private static char[][] charTable; private static Point[] positions;
public static void main(String[] args) { Scanner sc = new Scanner(System.in);
String key = prompt("Enter an encryption key (min length 6): ", sc, 6); String txt = prompt("Enter the message: ", sc, 1); String jti = prompt("Replace J with I? y/n: ", sc, 1);
boolean changeJtoI = jti.equalsIgnoreCase("y");
createTable(key, changeJtoI);
String enc = encode(prepareText(txt, changeJtoI));
System.out.printf("%nEncoded message: %n%s%n", enc); System.out.printf("%nDecoded message: %n%s%n", decode(enc)); }
private static String prompt(String promptText, Scanner sc, int minLen) { String s; do { System.out.print(promptText); s = sc.nextLine().trim(); } while (s.length() < minLen); return s; }
private static String prepareText(String s, boolean changeJtoI) { s = s.toUpperCase().replaceAll("[^A-Z]", ""); return changeJtoI ? s.replace("J", "I") : s.replace("Q", ""); }
private static void createTable(String key, boolean changeJtoI) { charTable = new char[5][5]; positions = new Point[26];
String s = prepareText(key + "ABCDEFGHIJKLMNOPQRSTUVWXYZ", changeJtoI);
int len = s.length(); for (int i = 0, k = 0; i < len; i++) { char c = s.charAt(i); if (positions[c - 'A'] == null) { charTable[k / 5][k % 5] = c; positions[c - 'A'] = new Point(k % 5, k / 5); k++; } } }
private static String encode(String s) { StringBuilder sb = new StringBuilder(s);
for (int i = 0; i < sb.length(); i += 2) {
if (i == sb.length() - 1) sb.append(sb.length() % 2 == 1 ? 'X' : "");
else if (sb.charAt(i) == sb.charAt(i + 1)) sb.insert(i + 1, 'X'); } return codec(sb, 1); }
private static String decode(String s) { return codec(new StringBuilder(s), 4); }
private static String codec(StringBuilder text, int direction) { int len = text.length(); for (int i = 0; i < len; i += 2) { char a = text.charAt(i); char b = text.charAt(i + 1);
int row1 = positions[a - 'A'].y; int row2 = positions[b - 'A'].y; int col1 = positions[a - 'A'].x; int col2 = positions[b - 'A'].x;
if (row1 == row2) { col1 = (col1 + direction) % 5; col2 = (col2 + direction) % 5;
} else if (col1 == col2) { row1 = (row1 + direction) % 5; row2 = (row2 + direction) % 5;
} else { int tmp = col1; col1 = col2; col2 = tmp; }
text.setCharAt(i, charTable[row1][col1]); text.setCharAt(i + 1, charTable[row2][col2]); } return text.toString(); }
}</lang>
alternative version
<lang java>import java.util.Scanner;
public class PlayfairCipherEncryption {
private String KeyWord = new String(); private String Key = new String(); private char matrix_arr[][] = new char[5][5]; public void setKey(String k) { String K_adjust = new String(); boolean flag = false; K_adjust = K_adjust + k.charAt(0); for (int i = 1; i < k.length(); i++) { for (int j = 0; j < K_adjust.length(); j++) { if (k.charAt(i) == K_adjust.charAt(j)) { flag = true; } } if (flag == false) K_adjust = K_adjust + k.charAt(i); flag = false; } KeyWord = K_adjust; } public void KeyGen() { boolean flag = true; char current; Key = KeyWord; for (int i = 0; i < 26; i++) { current = (char) (i + 97); if (current == 'j') continue; for (int j = 0; j < KeyWord.length(); j++) { if (current == KeyWord.charAt(j)) { flag = false; break; } } if (flag) Key = Key + current; flag = true; } System.out.println(Key); matrix(); } private void matrix() { int counter = 0; for (int i = 0; i < 5; i++) { for (int j = 0; j < 5; j++) { matrix_arr[i][j] = Key.charAt(counter); System.out.print(matrix_arr[i][j] + " "); counter++; } System.out.println(); } } private String format(String old_text) { int i = 0; int len = 0; String text = new String(); len = old_text.length(); for (int tmp = 0; tmp < len; tmp++) { if (old_text.charAt(tmp) == 'j') { text = text + 'i'; } else text = text + old_text.charAt(tmp); } len = text.length(); for (i = 0; i < len; i = i + 2) { if (text.charAt(i + 1) == text.charAt(i)) { text = text.substring(0, i + 1) + 'x' + text.substring(i + 1); } } return text; } private String[] Divid2Pairs(String new_string) { String Original = format(new_string); int size = Original.length(); if (size % 2 != 0) { size++; Original = Original + 'x'; } String x[] = new String[size / 2]; int counter = 0; for (int i = 0; i < size / 2; i++) { x[i] = Original.substring(counter, counter + 2); counter = counter + 2; } return x; } public int[] GetDiminsions(char letter) { int[] key = new int[2]; if (letter == 'j') letter = 'i'; for (int i = 0; i < 5; i++) { for (int j = 0; j < 5; j++) { if (matrix_arr[i][j] == letter) { key[0] = i; key[1] = j; break; } } } return key; } public String encryptMessage(String Source) { String src_arr[] = Divid2Pairs(Source); String Code = new String(); char one; char two; int part1[] = new int[2]; int part2[] = new int[2]; for (int i = 0; i < src_arr.length; i++) { one = src_arr[i].charAt(0); two = src_arr[i].charAt(1); part1 = GetDiminsions(one); part2 = GetDiminsions(two); if (part1[0] == part2[0]) { if (part1[1] < 4) part1[1]++; else part1[1] = 0; if (part2[1] < 4) part2[1]++; else part2[1] = 0; } else if (part1[1] == part2[1]) { if (part1[0] < 4) part1[0]++; else part1[0] = 0; if (part2[0] < 4) part2[0]++; else part2[0] = 0; } else { int temp = part1[1]; part1[1] = part2[1]; part2[1] = temp; } Code = Code + matrix_arr[part1[0]][part1[1]] + matrix_arr[part2[0]][part2[1]]; } return Code; } public static void main(String[] args) { PlayfairCipherEncryption x = new PlayfairCipherEncryption(); Scanner sc = new Scanner(System.in); System.out.println("Enter a keyword:"); String keyword = sc.next(); x.setKey(keyword); x.KeyGen(); System.out .println("Enter word to encrypt: (Make sure length of message is even)"); String key_input = sc.next(); if (key_input.length() % 2 == 0) { System.out.println("Encryption: " + x.encryptMessage(key_input)); } else { System.out.println("Message length should be even"); } sc.close(); }
}</lang>
Kotlin
<lang scala>// version 1.0.5-2
enum class PlayfairOption {
NO_Q, I_EQUALS_J
}
class Playfair(keyword: String, val pfo: PlayfairOption) {
private val table: Array<CharArray> = Array(5, { CharArray(5) }) // 5 x 5 char array
init { // build table val used = BooleanArray(26) // all elements false if (pfo == PlayfairOption.NO_Q) used[16] = true // Q used else used[9] = true // J used val alphabet = keyword.toUpperCase() + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" var i = 0 var j = 0 var c: Char var d: Int for (k in 0 until alphabet.length) { c = alphabet[k] if (c !in 'A'..'Z') continue d = c.toInt() - 65 if (!used[d]) { table[i][j] = c used[d] = true if (++j == 5) { if (++i == 5) break // table has been filled j = 0 } } } } private fun getCleanText(plainText: String): String { val plainText2 = plainText.toUpperCase() // ensure everything is upper case // get rid of any non-letters and insert X between duplicate letters var cleanText = "" var prevChar = '\u0000' // safe to assume null character won't be present in plainText var nextChar: Char for (i in 0 until plainText2.length) { nextChar = plainText2[i] // It appears that Q should be omitted altogether if NO_Q option is specified - we assume so anyway if (nextChar !in 'A'..'Z' || (nextChar == 'Q' && pfo == PlayfairOption.NO_Q)) continue // If I_EQUALS_J option specified, replace J with I if (nextChar == 'J' && pfo == PlayfairOption.I_EQUALS_J) nextChar = 'I' if (nextChar != prevChar) cleanText += nextChar else cleanText += "X" + nextChar prevChar = nextChar } val len = cleanText.length if (len % 2 == 1) { // dangling letter at end so add another letter to complete digram if (cleanText[len - 1] != 'X') cleanText += 'X' else cleanText += 'Z' } return cleanText }
private fun findChar(c: Char): Pair<Int, Int> { for (i in 0..4) for (j in 0..4) if (table[i][j] == c) return Pair(i, j) return Pair(-1, -1) }
fun encode(plainText: String): String { val cleanText = getCleanText(plainText) var cipherText = "" val length = cleanText.length for (i in 0 until length step 2) { val (row1, col1) = findChar(cleanText[i]) val (row2, col2) = findChar(cleanText[i + 1]) cipherText += when { row1 == row2 -> table[row1][(col1 + 1) % 5].toString() + table[row2][(col2 + 1) % 5] col1 == col2 -> table[(row1 + 1) % 5][col1].toString() + table[(row2 + 1) % 5][col2] else -> table[row1][col2].toString() + table[row2][col1] } if (i < length - 1) cipherText += " " } return cipherText }
fun decode(cipherText: String): String { var decodedText = "" val length = cipherText.length for (i in 0 until length step 3) { // cipherText will include spaces so we need to skip them val (row1, col1) = findChar(cipherText[i]) val (row2, col2) = findChar(cipherText[i + 1]) decodedText += when { row1 == row2 -> table[row1][if (col1 > 0) col1 - 1 else 4].toString() + table[row2][if (col2 > 0) col2 - 1 else 4] col1 == col2 -> table[if (row1 > 0) row1- 1 else 4][col1].toString() + table[if (row2 > 0) row2 - 1 else 4][col2] else -> table[row1][col2].toString() + table[row2][col1] } if (i < length - 1) decodedText += " " } return decodedText }
fun printTable() { println("The table to be used is :\n") for (i in 0..4) { for (j in 0..4) print(table[i][j] + " ") println() } }
}
fun main(args: Array<String>) {
print("Enter Playfair keyword : ") val keyword: String = readLine()!! var ignoreQ: String do { print("Ignore Q when buiding table y/n : ") ignoreQ = readLine()!!.toLowerCase() } while (ignoreQ != "y" && ignoreQ != "n") val pfo = if (ignoreQ == "y") PlayfairOption.NO_Q else PlayfairOption.I_EQUALS_J val playfair = Playfair(keyword, pfo) playfair.printTable() print("\nEnter plain text : ") val plainText: String = readLine()!! val encodedText = playfair.encode(plainText) println("\nEncoded text is : $encodedText") val decodedText = playfair.decode(encodedText) println("Decoded text is : $decodedText")
}</lang>
- Output:
Enter Playfair keyword : Playfair example Ignore Q when buiding table y/n : n The table to be used is : P L A Y F I R E X M B C D G H K N O Q S T U V W Z Enter plain text : Hide the gold...in the TREESTUMP!!!! Encoded text is : BM OD ZB XD NA BE KU DM UI XM MO UV IF Decoded text is : HI DE TH EG OL DI NT HE TR EX ES TU MP
NetRexx
<lang NetRexx>/* NetRexx */ options replace format comments java crossref symbols nobinary
-- input arguments: -- encipher/decipher IQ-switch key text -- encipher/decipher - -- a character E, D (default E; . is an alias for E) -- IQ-switch - -- a character I, Q (default I for I==J, Q for exclude Q; . is an alias for I) -- key - -- the cipher key - default plugh_xyzzy (really just PLUGHXYZ) -- text - -- the text to encipher/decipher
runSample(arg) return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method cipher(d_, km, digraphs) public static
if d_.upper() = 'D' then d_ = -1 -- encode or decode adjustment else d_ = +1 cipherText = loop dw = 1 to digraphs.words() -- process the digraphs one at a time digraph = digraphs.word(dw) cl = cr = -- get each letter from the digraph parse digraph dl +1 dr loop r_ = 1 to km[0] while (cl cr).words() < 4 -- locate the row/col of each letter in the cipher matrix clx = km[r_].wordpos(dl) crx = km[r_].wordpos(dr) if clx > 0 then cl = r_ clx if crx > 0 then cr = r_ crx end r_
-- process the digraph's rows, columns or rectangles select when cl.word(1) = cr.word(1) then do -- a row rx = cl.word(1) clx = cl.word(2) + d_ crx = cr.word(2) + d_ if clx > 5 then clx = 1 -- wrap if crx > 5 then crx = 1 if clx < 1 then clx = 5 if crx < 1 then crx = 5 cy = km[rx].word(clx) || km[rx].word(crx) cipherText = cipherText cy end when cl.word(2) = cr.word(2) then do -- a column cx = cl.word(2) rlx = cl.word(1) + d_ rrx = cr.word(1) + d_ if rlx > 5 then rlx = 1 -- wrap if rrx > 5 then rrx = 1 if rlx < 1 then rlx = 5 if rrx < 1 then rrx = 5 cy = km[rlx].word(cx) || km[rrx].word(cx) cipherText = cipherText cy end otherwise do -- a rectangle r1 = cl.word(1) r2 = cr.word(1) cy = km[r1].word(cr.word(2)) || km[r2].word(cl.word(2)) cipherText = cipherText cy end end end dw return cipherText.strip()
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method encipher(km, digraphs) public static
return cipher('E', km, digraphs)
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method decipher(km, digraphs) public static
return cipher('D', km, digraphs)
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method getDigraphs(text, IorQ, ED) private static
a2z = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' if ED.upper() \= 'D' then eks = 'X' else eks = tp = text.upper().translate(, a2z) text = text.upper().translate(' '.copies(tp.length()), tp).space(0) rtext = ll =
loop while text \= parse text lc +1 text if ll \= lc then rtext = rtext || lc else rtext = rtext || eks || lc ll = lc end
-- I == J or remove Q fixup if IorQ \= 'Q' then parse 'J I' IorQ sc . else sc =
rtext = rtext.changestr(IorQ, sc) if rtext.length() // 2 \= 0 then rtext = rtext || eks digraphs = loop while rtext \= parse rtext digraph +2 rtext digraphs = digraphs digraph end return digraphs.space()
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method getKey(key, IorQ) private static
a2z = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' kp = (key || a2z).upper() kr = loop while kp \= parse kp xx +1 kp if \xx.datatype('u') then iterate kr = kr xx kp = kp.changestr(xx, ) end
if IorQ = 'I' | IorQ = 'J' | IorQ = then kr = kr.changestr('J', ) else kr = kr.changestr('Q', )
return kr.space()
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method getKeyMatrix(kr) private static
km = loop r_ = 1 while kr \= parse kr kp +10 kr km[0] = r_ km[r_] = kp end r_ return km
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method runSample(arg) private static
parse arg ciph IorQ key text if ciph = | ciph = '.' then ciph = 'E' if IorQ = | IorQ = '.' then IorQ = 'I' if key = | key = '.' then key = 'plugh_xyzzy' if text = | text = '.' then text = 'NetRexx; not just a programing language for kings & queens!'
kr = getKey(key.space(0), IorQ) km = getKeyMatrix(kr)
digraphs = getDigraphs(text, IorQ, ciph) -- fixup for a Q in the text when Q is excluded (substitute K for Q) if IorQ.upper = 'Q' then digraphs = digraphs.changestr('Q', 'K') if ciph = 'E' then say text say digraphs if ciph.upper() = 'E' then say encipher(km, digraphs) else say decipher(km, digraphs)
return
</lang>
- Output:
$ java -cp .:.. RPlayfairCipher00 NetRexx; not just a programing language for kings & queens! NE TR EX XX NO TI US TA PR OG RA MI NG LA NG UA GE FO RK IN GS QU EX EN SX TN VS CZ YY OQ WE LT VZ XP VA VX QD OU GY OU GZ UF OV PR EQ LV NH CZ NT RY $ java -cp .:.. RPlayfairCipher00 d . . TN VS CZ YY OQ WE LT VZ XP VA VX QD OU GY OU GZ UF OV PR EQ LV NH CZ NT RY TN VS CZ YY OQ WE LT VZ XP VA VX QD OU GY OU GZ UF OV PR EQ LV NH CZ NT RY NE TR EX XX NO TI US TA PR OG RA MI NG LA NG UA GE FO RK IN GS QU EX EN SX $ java -cp .:.. RPlayfairCipher00 e q playfair Hide the gold in the tree stump\!\! Hide the gold in the tree stump!! HI DE TH EG OL DI NT HE TR EX ES TU MP EB IK OK GH NA IR OM JG ND JU JM MZ UI $ java -cp .:.. RPlayfairCipher00 d q playfair EB IK OK GH NA IR OM JG ND JU JM MZ UI EB IK OK GH NA IR OM JG ND JU JM MZ UI HI DE TH EG OL DI NT HE TR EX ES TU MP
ooRexx
<lang oorexx>/*---------------------------------------------------------------------
- REXX program implements a PLAYFAIR cipher (encryption & decryption).
- 11.11.2013 Walter Pachl revamped, for ooRexx, the REXX program
- the logic of which was devised by Gerard Schildberger
- Invoke as rexx pf O abcd efgh ( phrase to be processed
- Defaults: 'Playfair example.'
- J
- 'Hide the gold in the tree stump'
- Major changes: avoid language elements not allowed in ooRexx
- show use of a.[expr1,expr2]
- allow key to be more than one word
- add restriction of using X or Q in text
- 12.11.2013 change order of arguments
- and comment the use of a.[expr1,expr2]
- Program should run on all Rexxes that have changestr-bif
- --------------------------------------------------------------------*/
Parse Upper Version v oorexx=pos('OOREXX',v)>0
Parse Arg omit oldk '(' text If omit= Then omit='J' If oldk= Then oldk='Playfair example.' If text= Then text='Hide the gold in the tree stump!!'
newkey=scrub(oldk,1) newtext=scrub(text) If newtext== Then Call err 'TEXT is empty or has no letters' If length(omit)\==1 Then Call err 'OMIT letter must be only one letter' If\datatype(omit,'M') Then Call err 'OMIT letter must be a Latin alphabet letter.' omit=translate(omit) cant='must not contain the "OMIT" character: ' omit If pos(omit,newtext)\==0 Then Call err 'TEXT' cant If pos(omit,newkey)\==0 Then Call err 'cipher key' cant abc='abcdefghijklmnopqrstuvwxyz' abcu=translate(abc) /* uppercase alphabet */ abcx=space(translate(abcu,,omit),0) /*elide OMIT char from alphabet */ xx='X' /* char used for double characters*/ If omit==xx Then xx='Q' If pos(xx,newtext)>0 Then Call err 'Sorry,' xx 'is not allowed in text' If length(newkey)<3 Then Call err 'cipher key is too short, must be at least 3 different letters' abcx=space(translate(abcx,,newkey),0) /*remove any cipher characters */ grid=newkey||abcx /* only first 25 chars are used*/ Say 'old cipher key: ' strip(oldk) padl=14+2 pad=left(,padl) Say 'new cipher key: ' newkey padx=left(,padl,"-")'Playfair' Say ' omit char: ' omit /* [?] lowercase of double char. */ Say ' double char: ' xx lxx=translate(xx,abc,abcu) Say ' original text: ' strip(text)/* [?] doubled version of Lxx. */ Call show 'cleansed',newtext lxxlxx=lxx||lxx n=0 /* number of grid characters used.*/ Do row=1 For 5 /* build array of individual cells*/ Do col=1 For 5 n=n+1 a.row.col=substr(grid,n,1) If row==1 Then a.0.col=a.1.col If col==5 Then Do a.row.6=a.row.1 a.row.0=a.row.5 End If row==5 Then Do a.6.col=a.1.col a.0.col=a.5.col End End End
etext=playfair(newtext,1) Call show 'encrypted',etext ptext=playfair(etext,-1) Call show 'plain',ptext qtext=changestr(xx||xx,ptext,lxx) /*change doubled doublechar-?sing*/ qtext=changestr(lxx||xx,qtext,lxxlxx) /*change Xx --? lowercase dblChar*/ qtext=space(translate(qtext,,xx),0) /*remove char used for "doubles."*/ qtext=translate(qtext) /*reinstate the use of upperchars*/ Call show 'decoded',qtext Say ' original text: ' newtext /* ·· and show the original text.*/ Say Exit
playfair: /*---------------------------------------------------------------------
- encode (e=1) or decode (e=-1) the given text (t) using the grid
- --------------------------------------------------------------------*/
Arg t,e d= If e=1 Then Do Do k=1 By 1 Until c= c=substr(t,k,1) If substr(t,k+1,1)==c Then t=left(t,k)||lxx||substr(t,k+1) End End t=translate(t) Do j=1 By 2 To length(t) c2=strip(substr(t,j,2)) If length(c2)==1 Then c2=c2||xx /* append X or Q char, rule 1*/ Call LR Select /*- This could/should be used on ooRexx ------------------------- When rowl==rowr Then c2=a.[rowl,coll+e]a.[rowr,colr+e] /*rule 2*/ When coll==colr Then c2=a.[rowl+e,coll]a.[rowr+e,colr] /*rule 3*/ *--------------------------------------------------------------*/ When rowl==rowr Then c2=aa(rowl,coll+e)aa(rowr,colr+e) /*rule 2*/ When coll==colr Then c2=aa(rowl+e,coll)aa(rowr+e,colr) /*rule 3*/ Otherwise c2=a.rowl.colr||a.rowr.coll /*rule 4*/ End d=d||c2 End Return d
aa: /*---------------------------------------------------------------------
- ooRexx allows to use a.[rowl,coll+e]
- this function can be removed when ooRexx syntax is used to access a.
- --------------------------------------------------------------------*/
Parse Arg xrow,xcol Return a.xrow.xcol
err: /*---------------------------------------------------------------------
- Exit with an error message
- --------------------------------------------------------------------*/
Say Say '***error!***' arg(1) Say Exit 13
lr: /*---------------------------------------------------------------------
- get grid positions of the 2 characters
- --------------------------------------------------------------------*/
Parse Value rowcol(left(c2,1)) with rowl coll Parse Value rowcol(right(c2,1)) with rowr colr Return
rowcol: procedure Expose grid /*---------------------------------------------------------------------
- compute row and column of the given character in the 5x5 grid
- --------------------------------------------------------------------*/
Parse Arg c p=pos(c,grid) col=(p-1)//5+1 row=(4+p)%5 Return row col
show: /*---------------------------------------------------------------------
- Show heading and text
- --------------------------------------------------------------------*/
Arg,y Say Say right(arg(1) 'text: ',padl) digram(arg(2)) result=space(arg(2),0) If arg(1)='decoded' Then Do result=strip(result,'T',xx) End Say pad result Return
scrub: Procedure /*---------------------------------------------------------------------
- Remove all non-letters from the given string, uppercase letters
- and, if unique=1 remove duplicates
- 'aB + c1Bb' -> 'ABCBB' or 'ABC', respectively
- --------------------------------------------------------------------*/
Arg xxx,unique /* ARG caps all args */ d= used.=0 Do While xxx<> Parse Var xxx c +1 xxx If datatype(c,'U') Then If (unique=1 & pos(c,d)=0) |, unique<>1 Then d=d||c End Return d
digram: Procedure /*---------------------------------------------------------------------
- Return the given string as character pairs separated by blanks
- 'ABCDEF' -> 'AB CD EF'
- 'ABCDE' -> 'AB CD E'
- --------------------------------------------------------------------*/
Parse Arg x d= Do j=1 By 2 To length(x) d=d||substr(x,j,2)' ' End Return strip(d)</lang>
Output (sample):
old cipher key: this is my little key new cipher key: THISMYLEK omit char: X double char: Q original text: to be or not to bee cleansed text: TO BE OR NO TT OB EE TOBEORNOTTOBEE encrypted text: IJ DY JV OP MJ IJ DY OA JJ IJDYJVOPMJIJDYOAJJ plain text: TO BE OR NO TQ TO BE QE QQ TOBEORNOTQTOBEQEQQ decoded text: TO BE OR NO TT OB EE Q TOBEORNOTTOBEE original text: TOBEORNOTTOBEE
Perl 6
<lang perl6># Instantiate a specific encoder/decoder.
sub playfair( $key,
$from = 'J',
$to = $from eq 'J' ?? 'I' !! ) {
sub canon($str) { $str.subst(/<-alpha>/,, :g).uc.subst(/$from/,$to,:g) }
# Build 5x5 matrix. my @m = canon($key ~ ('A'..'Z').join).comb.unique.map: -> $a,$b,$c,$d,$e { [$a,$b,$c,$d,$e] }
# Pregenerate all forward translations. my %ENC = gather {
# Map pairs in same row. for @m -> @r { for ^@r X ^@r -> (\i,\j) { next if i == j; take @r[i] ~ @r[j] => @r[(i+1)%5] ~ @r[(j+1)%5]; } }
# Map pairs in same column. for ^5 -> $c { my @c = @m.map: *.[$c]; for ^@c X ^@c -> (\i,\j) { next if i == j; take @c[i] ~ @c[j] => @c[(i+1)%5] ~ @c[(j+1)%5]; } }
# Map pairs with cross-connections. for ^5 X ^5 X ^5 X ^5 -> (\i1,\j1,\i2,\j2) { next if i1 == i2 or j1 == j2; take @m[i1][j1] ~ @m[i2][j2] => @m[i1][j2] ~ @m[i2][j1]; }
}
# Generate reverse translations. my %DEC = %ENC.invert;
return
anon sub enc($red) { my @list = canon($red).comb(/(.) (.?) <?{ $1 ne $0 }>/); ~@list.map: { .chars == 1 ?? %ENC{$_~'X'} !! %ENC{$_} } }, anon sub dec($black) { my @list = canon($black).comb(/../); ~@list.map: { %DEC{$_} } } }
my (&encode,&decode) = playfair 'Playfair example';
my $orig = "Hide the gold in...the TREESTUMP!!!"; say " orig:\t$orig";
my $black = encode $orig; say "black:\t$black";
my $red = decode $black; say " red:\t$red";</lang>
- Output:
orig: Hide the gold in...the TREESTUMP!!! black: BM OD ZB XD NA BE KU DM UI XM MO UV IF red: HI DE TH EG OL DI NT HE TR EX ES TU MP
Python
<lang python>from string import ascii_uppercase from itertools import product from re import findall
def uniq(seq):
seen = {} return [seen.setdefault(x, x) for x in seq if x not in seen]
def partition(seq, n):
return [seq[i : i + n] for i in xrange(0, len(seq), n)]
"""Instantiate a specific encoder/decoder."""
def playfair(key, from_ = 'J', to = None):
if to is None: to = 'I' if from_ == 'J' else
def canonicalize(s): return filter(str.isupper, s.upper()).replace(from_, to)
# Build 5x5 matrix. m = partition(uniq(canonicalize(key + ascii_uppercase)), 5)
# Pregenerate all forward translations. enc = {}
# Map pairs in same row. for row in m: for i, j in product(xrange(5), repeat=2): if i != j: enc[row[i] + row[j]] = row[(i + 1) % 5] + row[(j + 1) % 5]
# Map pairs in same column. for c in zip(*m): for i, j in product(xrange(5), repeat=2): if i != j: enc[c[i] + c[j]] = c[(i + 1) % 5] + c[(j + 1) % 5]
# Map pairs with cross-connections. for i1, j1, i2, j2 in product(xrange(5), repeat=4): if i1 != i2 and j1 != j2: enc[m[i1][j1] + m[i2][j2]] = m[i1][j2] + m[i2][j1]
# Generate reverse translations. dec = dict((v, k) for k, v in enc.iteritems())
def sub_enc(txt): lst = findall(r"(.)(?:(?!\1)(.))?", canonicalize(txt)) return " ".join(enc[a + (b if b else 'X')] for a, b in lst)
def sub_dec(encoded): return " ".join(dec[p] for p in partition(canonicalize(encoded), 2))
return sub_enc, sub_dec
(encode, decode) = playfair("Playfair example")
orig = "Hide the gold in...the TREESTUMP!!!"
print "Original:", orig
enc = encode(orig)
print "Encoded:", enc
print "Decoded:", decode(enc)</lang>
- Output:
Original: Hide the gold in...the TREESTUMP!!! Encoded: BM OD ZB XD NA BE KU DM UI XM MO UV IF Decoded: HI DE TH EG OL DI NT HE TR EX ES TU MP
REXX
Quite a bit of the REXX code deals with error checking, accepting arguments, and displaying the options used, and displaying input and output.
For ease of viewing and comparing, the output is in capitalized digraphs (which are really digrams) as well as the original input(s).
Thanks to Walter Pachl, this program is now sensitive of using a suitable double character when X is present in the cipher key.
Also, more thanks are due to Walter Pachl for finding that the cipher key can't contain the OMIT character.
A fair amount of code was added to massage the decrypted encryption to remove doubled Xes so as to match the original text
(this is the possible text part of the REXX code).
<lang rexx>/*REXX program implements a PLAYFAIR cipher (encryption & decryption).*/
@abc='abcdefghijklmnopqrstuvwxyz'; @abcU=@abc /*lower and upper ABC's.*/
parse arg omit key '(' text /*TEXT is the phrase to be used. */ ;oldK=key /*save old.*/
if key == | key ==',' then do; key='Playfair example.'; oldK=key " ◄───using the default."; end
if omit== | omit==',' then omit='J' /*the "omitted" character. */
if text= then text='Hide the gold in the tree stump!!' /*default.*/
newKey =scrub(key , 1) /*scrub old cipher key──► newKey */
newText=scrub(text ) /* " " text ──► newText*/
if newText== then call err 'TEXT is empty or has no letters'
if length(omit)\==1 then call err 'OMIT letter must be only one letter'
if \datatype(omit,'M') then call err 'OMIT letter must be a Latin alphabet letter.'
upper omit @abcU /*uppercase OMIT char & alphabet.*/
cant='cant contain the "OMIT" character: ' omit
if pos(omit,newText)\==0 then call err 'TEXT' cant if pos(omit,newKey) \==0 then call err 'cipher key' cant fill=space(translate(@abcU,, omit), 0) /*elide OMIT char from alphabet. */ xx='X'; if omit==xx then xx='Q' /*char used for double characters*/ if length(newKey)<3 then call err 'cipher key is too short, must be ≥3 unique characters.' fill=space(translate(fill,,newKey),0) /*remove any cipher characters. */ grid=newKey || fill /*only first 25 chars are used.*/ say 'old cipher key: ' strip(oldK) ; padL=14+2; pad=left(,padL) say 'new cipher key: ' newKey ; padX=left(,padL,"═")'Playfair' say ' omit char: ' omit /* [↓] lowercase of double char.*/ say ' double char: ' xx ; Lxx=translate(xx, @abc, @abcU) say ' original text: ' strip(text) /* [↓] doubled version of Lxx. */ call show 'cleansed', newText ; LxxLxx=Lxx || Lxx
- =0 /*number of grid characters used.*/
do row =1 for 5 /*build array of individual cells*/ do col=1 for 5; #=#+1; @.row.col=substr(grid,#,1) if row==1 then @.0.col=@.1.col if col==5 then do; @.row.6=@.row.1; @.row.0=@.row.5; end if row==5 then do; @.6.col=@.1.col; @.0.col=@.5.col; end end /*col*/ end /*row*/
eText=.Playfair(newText, 1); call show 'encrypted' , eText pText=.Playfair(eText ); call show 'plain' , pText qText=changestr(xx ||xx,pText,Lxx) /*change doubled doublechar─►sing*/ qText=changestr(Lxx||xx,qText,LxxLxx) /*change Xx ──► lowercase dblChar*/ qText=space(translate(qText,,xx),0) /*remove char used for "doubles."*/ upper qText /*reinstate the use of upperchars*/ if length(qText)\==length(pText) then call show 'possible', qText say ' original text: ' newText; say /*··· and show the original text.*/ if qtext==newText then say padx 'encryption──► decryption──► encryption worked.' exit /*stick a fork in it, we're done.*/ /*──────────────────────────────────one─line subroutines───────────────────────────────*/ @@: parse arg Xrow,Xcol; return @.Xrow.Xcol err: say; say '***error!***' arg(1); say; exit 13 LR: rowL=row(left(__,1)); colL=_; rowR=row(right(__,1)); colR=_; return length(__) row: ?=pos(arg(1),grid); _=(?-1)//5+1; return (4+?)%5 show: arg ,y; say; say right(arg(1) 'text: ',padL) digram(y); say pad space(y,0); return /*──────────────────────────────────SCRUB subroutine────────────────────*/ scrub: procedure; arg xxx,unique; xxx=space(xxx,0) /*ARG caps all args*/ $=; do j=1 for length(xxx); _=substr(xxx,j,1)
if unique==1 then if pos(_,$)\==0 then iterate /*unique?*/ if datatype(_,'M') then $=$||_ /*only use Latin letters. */ end /*j*/
return $ /*──────────────────────────────────DIGRAM subroutine───────────────────*/ digram: procedure; parse arg x; $=; do j=1 by 2 to length(x)
$=$ || substr(x,j,2)' ' end /*j*/
return strip($) /*──────────────────────────────────.PLAYFAIR subroutine────────────────*/ .Playfair: arg T,encrypt; i=-1; if encrypt==1 then i=1; $=
do k=1 while i==1; _=substr(T,k,1); if _==' ' then leave if _==substr(T,k+1 ,1) then T=left(T,k) || Lxx || substr(T,k+1) end /*k*/
upper T
do j=1 by 2 to length(T); __=strip(substr(T,j,2)) if LR()==1 then __=__ || xx; call LR /*append X or Q char, rule 1*/ select when rowL==rowR then __=@@(rowL, colL+i)@@(rowR, colR+i) /*rule 2*/ when colL==colR then __=@@(rowL+i,colL )@@(rowR+i,colR) /*rule 3*/ otherwise __=@@(rowL, colR )@@(rowR, colL) /*rule 4*/ end /*select*/ $=$ || __ end /*j*/
return $</lang>
Some older REXXes don't have a changestr bif, so one is included here ──► CHANGESTR.REX.
output when using the default inputs:
old cipher key: Playfair example. ◄───using the default. new cipher key: PLAYFIREXM omit char: J double char: X original text: Hide the gold in the tree stump!! cleansed text: HI DE TH EG OL DI NT HE TR EE ST UM P HIDETHEGOLDINTHETREESTUMP encrypted text: BM OD ZB XD NA BE KU DM UI XM MO UV IF BMODZBXDNABEKUDMUIXMMOUVIF plain text: HI DE TH EG OL DI NT HE TR EX ES TU MP HIDETHEGOLDINTHETREXESTUMP possible text: HI DE TH EG OL DI NT HE TR EE ST UM P HIDETHEGOLDINTHETREESTUMP original text: HIDETHEGOLDINTHETREESTUMP ════════════════Playfair encryption──► decryption──► encryption worked.
output when using the input of: x stuvw (myteest
old cipher key: stuvw new cipher key: STUVW omit char: X double char: Q original text: myteest cleansed text: MY TE ES T MYTEEST encrypted text: NR WB ZB TU NRWBZBTU plain text: MY TE QE ST MYTEQEST possible text: MY TE ES T MYTEEST original text: MYTEEST ════════════════Playfair encryption──► decryption──► encryption worked.
SQL
<lang sql> --Clean up previous run IF EXISTS (SELECT *
FROM SYS.TYPES WHERE NAME = 'FairPlayTable') DROP TYPE FAIRPLAYTABLE
--Set Types CREATE TYPE FAIRPLAYTABLE AS TABLE (LETTER VARCHAR(1), COLID INT, ROWID INT)
GO
--Configuration Variables DECLARE @KEYWORD VARCHAR(25) = 'CHARLES' --Keyword for encryption DECLARE @INPUT VARCHAR(MAX) = 'Testing Seeconqz' --Word to be encrypted DECLARE @Q INT = 0 -- Q removed? DECLARE @ENCRYPT INT = 1 --Encrypt? --Setup Variables DECLARE @WORDS TABLE
( WORD_PRE VARCHAR(2), WORD_POST VARCHAR(2) )
DECLARE @T_TABLE FAIRPLAYTABLE DECLARE @NEXTLETTER CHAR(1) DECLARE @WORD VARCHAR(2),
@COL1 INT, @COL2 INT, @ROW1 INT, @ROW2 INT, @TMP INT
DECLARE @SQL NVARCHAR(MAX) = ,
@COUNTER INT = 1, @I INT = 1
DECLARE @COUNTER_2 INT = 1
SET @INPUT = REPLACE(@INPUT, ' ', ) SET @KEYWORD = UPPER(@KEYWORD)
DECLARE @USEDLETTERS VARCHAR(MAX) = DECLARE @TESTWORDS VARCHAR(2),
@A INT = 0
WHILE @COUNTER_2 <= 5
BEGIN WHILE @COUNTER <= 5 BEGIN IF LEN(@KEYWORD) > 0 BEGIN SET @NEXTLETTER = LEFT(@KEYWORD, 1) SET @KEYWORD = RIGHT(@KEYWORD, LEN(@KEYWORD) - 1)
IF CHARINDEX(@NEXTLETTER, @USEDLETTERS) = 0 BEGIN INSERT INTO @T_TABLE SELECT @NEXTLETTER, @COUNTER, @COUNTER_2
SET @COUNTER = @COUNTER + 1 SET @USEDLETTERS = @USEDLETTERS + @NEXTLETTER END END ELSE BEGIN WHILE 1 = 1 BEGIN IF CHARINDEX(CHAR(64 + @I), @USEDLETTERS) = 0 AND NOT ( CHAR(64 + @I) = 'Q' AND @Q = 1 ) AND NOT ( @Q = 0 AND CHAR(64 + @I) = 'J' ) BEGIN SET @NEXTLETTER = CHAR(64 + @I) SET @USEDLETTERS = @USEDLETTERS + CHAR(64 + @I) SET @I = @I + 1
BREAK END
SET @I = @I + 1 END
-- SELECT 1 AS [T] --BREAK INSERT INTO @T_TABLE SELECT @NEXTLETTER, @COUNTER, @COUNTER_2
SET @COUNTER = @COUNTER + 1 END END
SET @COUNTER_2 = @COUNTER_2 + 1 SET @COUNTER = 1 END
--Split word into Digraphs WHILE @A < 1
BEGIN SET @TESTWORDS = UPPER(LEFT(@INPUT, 2))
IF LEN(@TESTWORDS) = 1 BEGIN SET @TESTWORDS = @TESTWORDS + 'X' SET @A = 1 END ELSE IF RIGHT(@TESTWORDS, 1) = LEFT(@TESTWORDS, 1) BEGIN SET @TESTWORDS = RIGHT(@TESTWORDS, 1) + 'X' SET @INPUT = RIGHT(@INPUT, LEN(@INPUT) - 1) END ELSE SET @INPUT = RIGHT(@INPUT, LEN(@INPUT) - 2)
IF LEN(@INPUT) = 0 SET @A = 1
INSERT @WORDS SELECT @TESTWORDS, END
--Start Encryption IF @ENCRYPT = 1
BEGIN --Loop through Digraphs amd encrypt DECLARE WORDS_LOOP CURSOR LOCAL FORWARD_ONLY FOR SELECT WORD_PRE FROM @WORDS FOR UPDATE OF WORD_POST
OPEN WORDS_LOOP
FETCH NEXT FROM WORDS_LOOP INTO @WORD
WHILE @@FETCH_STATUS = 0 BEGIN --Find letter positions SET @ROW1 = (SELECT ROWID FROM @T_TABLE WHERE LETTER = LEFT(@WORD, 1)) SET @ROW2 = (SELECT ROWID FROM @T_TABLE WHERE LETTER = RIGHT(@WORD, 1)) SET @COL1 = (SELECT COLID FROM @T_TABLE WHERE LETTER = LEFT(@WORD, 1)) SET @COL2 = (SELECT COLID FROM @T_TABLE WHERE LETTER = RIGHT(@WORD, 1))
--Move positions according to encryption rules IF @COL1 = @COL2 BEGIN SET @ROW1 = @ROW1 + 1 SET @ROW2 = @ROW2 + 1 --select 'row' END ELSE IF @ROW1 = @ROW2 BEGIN SET @COL1 = @COL1 + 1 SET @COL2 = @COL2 + 1 --select 'col' END ELSE BEGIN SET @TMP = @COL2 SET @COL2 = @COL1 SET @COL1 = @TMP --select 'reg' END
IF @ROW1 = 6 SET @ROW1 = 1
IF @ROW2 = 6 SET @ROW2 = 1
IF @COL1 = 6 SET @COL1 = 1
IF @COL2 = 6 SET @COL2 = 1
--Find encrypted letters by positions UPDATE @WORDS SET WORD_POST = (SELECT (SELECT LETTER FROM @T_TABLE WHERE ROWID = @ROW1 AND COLID = @COL1) + (SELECT LETTER FROM @T_TABLE WHERE COLID = @COL2 AND ROWID = @ROW2)) WHERE WORD_PRE = @WORD
FETCH NEXT FROM WORDS_LOOP INTO @WORD END
CLOSE WORDS_LOOP
DEALLOCATE WORDS_LOOP END
--Start Decryption ELSE
BEGIN --Loop through Digraphs amd decrypt DECLARE WORDS_LOOP CURSOR LOCAL FORWARD_ONLY FOR SELECT WORD_PRE FROM @WORDS FOR UPDATE OF WORD_POST
OPEN WORDS_LOOP
FETCH NEXT FROM WORDS_LOOP INTO @WORD
WHILE @@FETCH_STATUS = 0 BEGIN --Find letter positions SET @ROW1 = (SELECT ROWID FROM @T_TABLE WHERE LETTER = LEFT(@WORD, 1)) SET @ROW2 = (SELECT ROWID FROM @T_TABLE WHERE LETTER = RIGHT(@WORD, 1)) SET @COL1 = (SELECT COLID FROM @T_TABLE WHERE LETTER = LEFT(@WORD, 1)) SET @COL2 = (SELECT COLID FROM @T_TABLE WHERE LETTER = RIGHT(@WORD, 1))
--Move positions according to encryption rules IF @COL1 = @COL2 BEGIN SET @ROW1 = @ROW1 - 1 SET @ROW2 = @ROW2 - 1 --select 'row' END ELSE IF @ROW1 = @ROW2 BEGIN SET @COL1 = @COL1 - 1 SET @COL2 = @COL2 - 1 --select 'col' END ELSE BEGIN SET @TMP = @COL2 SET @COL2 = @COL1 SET @COL1 = @TMP --select 'reg' END
IF @ROW1 = 0 SET @ROW1 = 5
IF @ROW2 = 0 SET @ROW2 = 5
IF @COL1 = 0 SET @COL1 = 5
IF @COL2 = 0 SET @COL2 = 5
--Find decrypted letters by positions UPDATE @WORDS SET WORD_POST = (SELECT (SELECT LETTER FROM @T_TABLE WHERE ROWID = @ROW1 AND COLID = @COL1) + (SELECT LETTER FROM @T_TABLE WHERE COLID = @COL2 AND ROWID = @ROW2)) WHERE WORD_PRE = @WORD
FETCH NEXT FROM WORDS_LOOP INTO @WORD END
CLOSE WORDS_LOOP
DEALLOCATE WORDS_LOOP END
--Output DECLARE WORDS CURSOR LOCAL FAST_FORWARD FOR
SELECT WORD_POST FROM @WORDS
OPEN WORDS
FETCH NEXT FROM WORDS INTO @WORD
WHILE @@FETCH_STATUS = 0
BEGIN SET @SQL = @SQL + @WORD + ' '
FETCH NEXT FROM WORDS INTO @WORD END
CLOSE WORDS
DEALLOCATE WORDS
SELECT @SQL
--Cleanup IF EXISTS (SELECT *
FROM SYS.TYPES WHERE NAME = 'FairPlayTable') DROP TYPE FAIRPLAYTABLE
</lang>
Tcl
<lang tcl>package require TclOO
oo::class create Playfair {
variable grid lookup excluder constructor {{keyword "PLAYFAIR EXAMPLE"} {exclude "J"}} {
# Tweaking according to exact operation mode if {$exclude eq "J"} { set excluder "J I" } else { set excluder [list $exclude ""] }
# Clean up the keyword source set keys [my Clean [append keyword "ABCDEFGHIJKLMNOPQRSTUVWXYZ"]]
# Generate the encoding grid set grid [lrepeat 5 [lrepeat 5 ""]] set idx -1 for {set i 0} {$i < 5} {incr i} {for {set j 0} {$j < 5} {} { if {![info exist lookup([set c [lindex $keys [incr idx]]])]} { lset grid $i $j $c set lookup($c) [list $i $j] incr j } }}
# Sanity check if {[array size lookup] != 25} { error "failed to build encoding table correctly" }
}
# Worker to apply a consistent cleanup/split rule method Clean {str} {
set str [string map $excluder [string toupper $str]] split [regsub -all {[^A-Z]} $str ""] ""
}
# These public methods are implemented by a single non-public method forward encode my Transform 1 forward decode my Transform -1
# The application of the Playfair cypher transform method Transform {direction message} {
# Split message into true digraphs foreach c [my Clean $message] { if {![info exists lookup($c)]} continue if {[info exist c0]} { lappend digraphs $c0 [expr {$c0 eq $c ? "X" : $c}] unset c0 } else { set c0 $c } } if {[info exist c0]} { lappend digraphs $c0 "Z" }
# Encode the digraphs set result "" foreach {a b} $digraphs { lassign $lookup($a) ai aj lassign $lookup($b) bi bj if {$ai == $bi} { set aj [expr {($aj + $direction) % 5}] set bj [expr {($bj + $direction) % 5}] } elseif {$aj == $bj} { set ai [expr {($ai + $direction) % 5}] set bi [expr {($bi + $direction) % 5}] } else { set tmp $aj set aj $bj set bj $tmp } lappend result [lindex $grid $ai $aj][lindex $grid $bi $bj] }
# Real use would be: return [join $result ""] return $result
}
}</lang> Demonstrating: <lang tcl>Playfair create cypher "Playfair Example" set plaintext "Hide the gold in...the TREESTUMP!!!" set encoded [cypher encode $plaintext] set decoded [cypher decode $encoded] puts "Original: $plaintext" puts "Encoded: $encoded" puts "Decoded: $decoded"</lang>
- Output:
Original: Hide the gold in...the TREESTUMP!!! Encoded: BM OD ZB XD NA BE KU DM UI XM KZ ZR FT Decoded: HI DE TH EG OL DI NT HE TR EX ST UM PZ
zkl
<lang zkl>fcn genKeyTable(key,deadChr){ // deadChr=="Q" or "J"
deadChr=deadChr.toUpper(); key=key.toUpper().unique() - " " - deadChr; return(key + (["A".."Z"].pump(String) - deadChr - key), deadChr);
}</lang> <lang zkl>fcn playfair(text,keytable){ // text is a-z only
keyTable,deadChr:=keytable; text=text.toUpper(); text-=text - keyTable; // remove unencodable characters if(deadChr=="Q") text-=deadChr; else text=text.replace("J","I");
text=text.pump(String,T(Void.Read,1,False),
fcn(a,b=""){ if(a==b) a+"X"+b else a+b });
if(text.len().isOdd) text+="Z";
row:='wrap(c){ keyTable.index(c)/5 }; col:='wrap(c){ keyTable.index(c)%5 }; ltrRight:='wrap(c){ keyTable[(keyTable.index(c) + 1)%25] }; ltrBelow:='wrap(c){ keyTable[(keyTable.index(c) + 5)%25] }; ltrAt:='wrap(r,c) { keyTable[r*5 + c] };
text.pump(String, Void.Read, //-->digraph 'wrap(a,b){
if((ra:=row(a))==(rb:=row(b))) return(ltrRight(a) + ltrRight(b)); if((ca:=col(a))==(cb:=col(b))) return(ltrBelow(a) + ltrBelow(b)); return(ltrAt(ra,cb) + ltrAt(rb,ca));
}) .pump(String,Void.Read,"".create.fp(" ")).strip(); // insert blanks
}</lang> <lang zkl>fcn decodePF(text,keyTable){
keyTable,_=keyTable; text-=" "; row:='wrap(c){ keyTable.index(c)/5 }; col:='wrap(c){ keyTable.index(c)%5 }; ltrLeft:='wrap(c){ keyTable[(keyTable.index(c) - 1)%25] }; ltrUp:='wrap(c){ n:=keyTable.index(c) - 5; if(n<0)n+=25; keyTable[n%25] }; ltrAt:='wrap(r,c){ keyTable[r*5 + c] }; text.pump(String,Void.Read, //-->digraph 'wrap(a,b){
if((ra:=row(a))==(rb:=row(b))) return(ltrLeft(a) + ltrLeft(b)); if((ca:=col(a))==(cb:=col(b))) return(ltrUp(a) + ltrUp(b)); return(ltrAt(ra,cb) + ltrAt(rb,ca));
}) .pump(String,Void.Read,"".create.fp(" ")).strip(); // insert blanks
} </lang> <lang zkl>msg:="Hide the gold in the tree stump!!!"; keyTable:=genKeyTable("playfair example"); msg.println(); e:=playfair(msg,keyTable); e.println(); decodePF(e,keyTable).println(); playfair("XX",keyTable).println() : decodePF(_,keyTable).println();</lang>
- Output:
Hide the gold in the tree stump!!! BM OD ZB XD NA BE KU DM UI XM MO UV IF HI DE TH EG OL DI NT HE TR EX ES TU MP MM MW XX XZ