Playfair cipher: Difference between revisions

=={{header|Mathematica}}/{{header|Wolfram Language}}==

<lang Mathematica>ClearAll[MakeTranslationTable, PlayfairCipher, PlayfairDecipher]

MakeTranslationTable[tt_List] := Module[{poss, in, out},

poss = Tuples[Tuples[Range[5], 2], 2];

Table[

If[p[[1, 1]] == p[[2, 1]],

(* same row *)

{in, out} = {p, {{p[[1, 1]], Mod[p[[1, 2]] + 1, 5, 1]}, {p[[2, 1]], Mod[p[[2, 2]] + 1, 5, 1]}}};

,

If[p[[1, 2]] == p[[2, 2]],

(* same column *)

{in, out} = {p, {{Mod[p[[1, 1]] + 1, 5, 1], p[[1, 2]]}, {Mod[p[[2, 1]] + 1, 5, 1], p[[2, 2]]}}};

,

(*rectangle*)

{in, out} = {p, {{p[[1, 1]], p[[2, 2]]}, {p[[2, 1]], p[[1, 2]]}}};

]

];

StringJoin[Extract[tt, in]] -> StringJoin[Extract[tt, out]]

,

{p, poss}

]

]

PlayfairCipher[txt_String, key_String, iisj_ : True] :=

Module[{text, tt},

text = RemoveDiacritics[ToUpperCase[txt]];

tt = RemoveDiacritics[ToUpperCase[key]] <> CharacterRange["A", "Z"];

text //= StringReplace[Except[Alternatives @@ CharacterRange["A", "Z"]] -> ""];

tt //= StringReplace[Except[Alternatives @@ CharacterRange["A", "Z"]] -> ""];

If[iisj,

tt //= StringReplace["J" -> "I"];

text //= StringReplace["J" -> "I"];

,

tt //= StringReplace["Q" -> ""];

text //= StringReplace["Q" -> ""];

];

tt //= Characters /* DeleteDuplicates;

text = FixedPoint[StringReplace[#, x_ ~~ x_ :> x ~~ "X" ~~ x, 1] &, text];

If[OddQ[StringLength[text]], text = text <> "X"];

If[Length[tt] == 25,

tt = Partition[tt, 5];

tt = MakeTranslationTable[tt];

text = StringPartition[text, 2];

StringRiffle[text /. tt, " "]

,

Print["Something went wrong!"]

]

]

PlayfairDecipher[txt_String, key_String, iisj_ : True] :=

Module[{text, tt},

text = RemoveDiacritics[ToUpperCase[txt]];

tt = RemoveDiacritics[ToUpperCase[key]] <> CharacterRange["A", "Z"];

text //= StringReplace[Except[Alternatives @@ CharacterRange["A", "Z"]] -> ""];

tt //= StringReplace[Except[Alternatives @@ CharacterRange["A", "Z"]] -> ""];

If[iisj,

tt //= StringReplace["J" -> "I"];

text //= StringReplace["J" -> "I"];

,

tt //= StringReplace["Q" -> ""];

text //= StringReplace["Q" -> ""];

];

tt //= Characters /* DeleteDuplicates;

If[OddQ[StringLength[text]], text = text <> "X"];

If[Length[tt] == 25,

tt = Partition[tt, 5];

tt = MakeTranslationTable[tt];

text = StringPartition[text, 2];

StringRiffle[text /. (Reverse /@ tt), " "]

,

Print["Something went wrong!"]

]

]

PlayfairCipher["Hide the gold in...the TREESTUMP!!!", "Playfair example"]

PlayfairDecipher[%, "Playfair example"]</lang>

{{out}}

<pre>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</pre>