Data update

Task/Chaocipher/Ada/chaocipher.ada

@@ -1,101 +0,0 @@
-with Ada.Text_IO; use Ada.Text_IO;
-
-procedure chao_slices is
-   type iMode is (Encrypt, Decrypt);
-
-   L_Alphabet : String := "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
-   R_Alphabet : String := "PTLNBQDEOYSFAVZKGJRIHWXUMC";
-   plaintext  : String := "WELLDONEISBETTERTHANWELLSAID";
-   ciphertext : String (1 .. plaintext'length);
-   plaintext2 : String (1 .. plaintext'length);
-   offset     : Natural;
-
-   function IndexOf (Source : String; Value : Character) return Positive is
-      Result : Positive;
-
-   begin
-      for I in Source'Range loop
-         if Source (I) = Value then
-            Result := I;
-            exit;
-         end if;
-      end loop;
-      return Result;
-   end IndexOf;
-
-   function Exec
-     (Text : String; mode : iMode; showsteps : Boolean := False) return String
-   is
-      etext : String (Text'First .. Text'Last);
-      temp  : String (1 .. 26);
-      index : Positive;
-      store : Character;
-      left  : String := L_Alphabet;
-      right : String := R_Alphabet;
-   begin
-      for I in Text'Range loop
-         if showsteps then
-            Put_Line (left & "  " & right);
-         end if;
-
-         if mode = Encrypt then
-            index     := IndexOf (Source => right, Value => Text (I));
-            etext (I) := left (index);
-         else
-            index     := IndexOf (Source => left, Value => Text (I));
-            etext (I) := right (index);
-         end if;
-
-         exit when I = Text'Last;
-
-         -- permute left
-         -- The array value permutations are performed using array slices
-         -- rather than explicit loops
-
-         if index > 1 then
-            offset                 := 26 - index;
-            temp (1 .. offset + 1) := left (index .. index + offset);
-
-            temp (offset + 2 .. 26) := left (1 .. index - 1);
-            store                   := temp (2);
-
-            temp (2 .. 13) := temp (3 .. 14);
-            temp (14)      := store;
-            left           := temp;
-
-            -- permute right
-            -- The array value permutations are performed using array slices
-            -- rather than explicit loops
-
-            temp (1 .. offset + 1) := right (index .. index + offset);
-
-            temp (offset + 2 .. 26) := right (1 .. index - 1);
-            store                   := temp (1);
-
-            temp (1 .. 25) := temp (2 .. 26);
-            temp (26)      := store;
-            store          := temp (3);
-
-            temp (3 .. 13) := temp (4 .. 14);
-            temp (14)      := store;
-            right          := temp;
-         end if;
-
-      end loop;
-
-      return etext;
-
-   end Exec;
-begin
-   Put_Line ("The original text is : " & plaintext);
-   New_Line;
-   Put_Line
-     ("The left and right alphabets after each permutation during encryption are:");
-   New_Line;
-   ciphertext := Exec (plaintext, Encrypt, True);
-   New_Line;
-   Put_Line ("The ciphertext is : " & ciphertext);
-   plaintext2 := Exec (ciphertext, Decrypt);
-   New_Line;
-   Put_Line ("The recovered plaintext is : " & plaintext2);
-end chao_slices;