L[1]  := Ord(Input[7] and 64 > 0); R[1]  := Ord(Input[7] and 128 > 0);
  L[2]  := Ord(Input[6] and 64 > 0); R[2]  := Ord(Input[6] and 128 > 0);
  L[3]  := Ord(Input[5] and 64 > 0); R[3]  := Ord(Input[5] and 128 > 0);
  L[4]  := Ord(Input[4] and 64 > 0); R[4]  := Ord(Input[4] and 128 > 0);
  L[5]  := Ord(Input[3] and 64 > 0); R[5]  := Ord(Input[3] and 128 > 0);
  L[6]  := Ord(Input[2] and 64 > 0); R[6]  := Ord(Input[2] and 128 > 0);
  L[7]  := Ord(Input[1] and 64 > 0); R[7]  := Ord(Input[1] and 128 > 0);
  L[8]  := Ord(Input[0] and 64 > 0); R[8]  := Ord(Input[0] and 128 > 0);
  L[9]  := Ord(Input[7] and 16 > 0); R[9]  := Ord(Input[7] and 32 > 0);
  L[10] := Ord(Input[6] and 16 > 0); R[10] := Ord(Input[6] and 32 > 0);
  L[11] := Ord(Input[5] and 16 > 0); R[11] := Ord(Input[5] and 32 > 0);
  L[12] := Ord(Input[4] and 16 > 0); R[12] := Ord(Input[4] and 32 > 0);
  L[13] := Ord(Input[3] and 16 > 0); R[13] := Ord(Input[3] and 32 > 0);
  L[14] := Ord(Input[2] and 16 > 0); R[14] := Ord(Input[2] and 32 > 0);
  L[15] := Ord(Input[1] and 16 > 0); R[15] := Ord(Input[1] and 32 > 0);
  L[16] := Ord(Input[0] and 16 > 0); R[16] := Ord(Input[0] and 32 > 0);
  L[17] := Ord(Input[7] and 4 > 0);  R[17] := Ord(Input[7] and 8 > 0);
  L[18] := Ord(Input[6] and 4 > 0);  R[18] := Ord(Input[6] and 8 > 0);
  L[19] := Ord(Input[5] and 4 > 0);  R[19] := Ord(Input[5] and 8 > 0);
  L[20] := Ord(Input[4] and 4 > 0);  R[20] := Ord(Input[4] and 8 > 0);
  L[21] := Ord(Input[3] and 4 > 0);  R[21] := Ord(Input[3] and 8 > 0);
  L[22] := Ord(Input[2] and 4 > 0);  R[22] := Ord(Input[2] and 8 > 0);
  L[23] := Ord(Input[1] and 4 > 0);  R[23] := Ord(Input[1] and 8 > 0);
  L[24] := Ord(Input[0] and 4 > 0);  R[24] := Ord(Input[0] and 8 > 0);
  L[25] := Input[7] and 1;           R[25] := Ord(Input[7] and 2 > 0);
  L[26] := Input[6] and 1;           R[26] := Ord(Input[6] and 2 > 0);
  L[27] := Input[5] and 1;           R[27] := Ord(Input[5] and 2 > 0);
  L[28] := Input[4] and 1;           R[28] := Ord(Input[4] and 2 > 0);
  L[29] := Input[3] and 1;           R[29] := Ord(Input[3] and 2 > 0);
  L[30] := Input[2] and 1;           R[30] := Ord(Input[2] and 2 > 0);
  L[31] := Input[1] and 1;           R[31] := Ord(Input[1] and 2 > 0);
  L[32] := Input[0] and 1;           R[32] := Ord(Input[0] and 2 > 0); 

  for n := 1 to 16 do
    begin
    z := ((R[32] xor G[n, 1]) shl 5) or ((R[5] xor G[n, 6]) shl 4)
      or ((R[ 1] xor G[n, 2]) shl 3) or ((R[2] xor G[n, 3]) shl 2)
      or ((R[ 3] xor G[n, 4]) shl 1) or ( R[4] xor G[n, 5]);
    F[ 9] := L[ 9] xor SA1[z];
    F[17] := L[17] xor SB1[z];
    F[23] := L[23] xor SC1[z];
    F[31] := L[31] xor SD1[z]; 

    z := ((R[4] xor G[n,  7]) shl 5) or ((R[9] xor G[n, 12]) shl 4)
      or ((R[5] xor G[n,  8]) shl 3) or ((R[6] xor G[n,  9]) shl 2)
      or ((R[7] xor G[n, 10]) shl 1) or ( R[8] xor G[n, 11]);
    F[13] := L[13] xor SA2[z];
    F[28] := L[28] xor SB2[z];
    F[ 2] := L[ 2] xor SC2[z];
    F[18] := L[18] xor SD2[z]; 

    z := ((R[ 8] xor G[n, 13]) shl 5) or ((R[13] xor G[n, 18]) shl 4)
      or ((R[ 9] xor G[n, 14]) shl 3) or ((R[10] xor G[n, 15]) shl 2)
      or ((R[11] xor G[n, 16]) shl 1) or ( R[12] xor G[n, 17]);
    F[24] := L[24] xor SA3[z];
    F[16] := L[16] xor SB3[z];
    F[30] := L[30] xor SC3[z];
    F[ 6] := L[ 6] xor SD3[z]; 

    z := ((R[12] xor G[n, 19]) shl 5) or ((R[17] xor G[n, 24]) shl 4)
      or ((R[13] xor G[n, 20]) shl 3) or ((R[14] xor G[n, 21]) shl 2)
      or ((R[15] xor G[n, 22]) shl 1) or ( R[16] xor G[n, 23]);
    F[26] := L[26] xor SA4[z];
    F[20] := L[20] xor SB4[z];
    F[10] := L[10] xor SC4[z];
    F[ 1] := L[ 1] xor SD4[z]; 

    z := ((R[16] xor G[n, 25]) shl 5) or ((R[21] xor G[n, 30]) shl 4)
      or ((R[17] xor G[n, 26]) shl 3) or ((R[18] xor G[n, 27]) shl 2)
      or ((R[19] xor G[n, 28]) shl 1) or ( R[20] xor G[n, 29]);
    F[ 8] := L[ 8] xor SA5[z];
    F[14] := L[14] xor SB5[z];
    F[25] := L[25] xor SC5[z];
    F[ 3] := L[ 3] xor SD5[z]; 

    z := ((R[20] xor G[n, 31]) shl 5) or ((R[25] xor G[n, 36]) shl 4)
      or ((R[21] xor G[n, 32]) shl 3) or ((R[22] xor G[n, 33]) shl 2)
      or ((R[23] xor G[n, 34]) shl 1) or ( R[24] xor G[n, 35]);
    F[ 4] := L[ 4] xor SA6[z];
    F[29] := L[29] xor SB6[z];
    F[11] := L[11] xor SC6[z];
    F[19] := L[19] xor SD6[z]; 

    z := ((R[24] xor G[n, 37]) shl 5) or ((R[29] xor G[n, 42]) shl 4)
      or ((R[25] xor G[n, 38]) shl 3) or ((R[26] xor G[n, 39]) shl 2)
      or ((R[27] xor G[n, 40]) shl 1) or ( R[28] xor G[n, 41]);
    F[32] := L[32] xor SA7[z];
    F[12] := L[12] xor SB7[z];
    F[22] := L[22] xor SC7[z];
    F[ 7] := L[ 7] xor SD7[z]; 

    z := ((R[28] xor G[n, 43]) shl 5) or ((R[ 1] xor G[n, 48]) shl 4)
      or ((R[29] xor G[n, 44]) shl 3) or ((R[30] xor G[n, 45]) shl 2)
      or ((R[31] xor G[n, 46]) shl 1) or ( R[32] xor G[n, 47]);
    F[ 5] := L[ 5] xor SA8[z];
    F[27] := L[27] xor SB8[z];
    F[15] := L[15] xor SC8[z];
    F[21] := L[21] xor SD8[z]; 

    L := R;
    R := F;
    end;
    
  Output[0] := (L[8] shl 7) or (R[8] shl 6) or (L[16] shl 5) or (R[16] shl 4)
    or (L[24] shl 3) or (R[24] shl 2) or (L[32] shl 1) or R[32];
  Output[1] := (L[7] shl 7) or (R[7] shl 6) or (L[15] shl 5) or (R[15] shl 4)
    or (L[23] shl 3) or (R[23] shl 2) or (L[31] shl 1) or R[31];
  Output[2] := (L[6] shl 7) or (R[6] shl 6) or (L[14] shl 5) or (R[14] shl 4)
    or (L[22] shl 3) or (R[22] shl 2) or (L[30] shl 1) or R[30];
  Output[3] := (L[5] shl 7) or (R[5] shl 6) or (L[13] shl 5) or (R[13] shl 4)
    or (L[21] shl 3) or (R[21] shl 2) or (L[29] shl 1) or R[29];
  Output[4] := (L[4] shl 7) or (R[4] shl 6) or (L[12] shl 5) or (R[12] shl 4)
    or (L[20] shl 3) or (R[20] shl 2) or (L[28] shl 1) or R[28];
  Output[5] := (L[3] shl 7) or (R[3] shl 6) or (L[11] shl 5) or (R[11] shl 4)
    or (L[19] shl 3) or (R[19] shl 2) or (L[27] shl 1) or R[27];
  Output[6] := (L[2] shl 7) or (R[2] shl 6) or (L[10] shl 5) or (R[10] shl 4)
    or (L[18] shl 3) or (R[18] shl 2) or (L[26] shl 1) or R[26];
  Output[7] := (L[1] shl 7) or (R[1] shl 6) or (L[9] shl 5) or (R[9] shl 4)
    or (L[17] shl 3) or (R[17] shl 2) or (L[25] shl 1) or R[25];
end; 

function StrToKey(aKey: string): TBlock;
var
  Key : TBlock;
  I   : Integer;
begin
  FillChar(Key, SizeOf(TBlock), 0);
  for I := 1 to Length(aKey) do
    begin
    Key[I mod SizeOf(TBlock)] := Key[I mod SizeOf(TBlock)] + Ord(aKey[I]);
    end; 

  result := Key;
end; 

function EnCrypt(aStr: string; acKey: string ): string;
var
  ReadBuf : TBlock;
  WriteBuf: TBlock;
  Key     : TBlock;
  Count   : Integer;
  Offset  : Integer; 

  I   : Integer;
  S   : string;
begin
  result := ''; 

  Key := StrToKey(acKey);
  Des_Init(Key, True); 

  Offset := 1;
  Count  := Length(aStr);
  repeat
    S := Copy(aStr, Offset, 8);
    FillChar(ReadBuf, 8, 0);
    Move(S[1], ReadBuf, Length(S));
    Des_Code(ReadBuf, WriteBuf); 

    for I := 0 to 7 do
      begin
      result := result + IntToHex(WriteBuf[I], 2);
      end; 

    Offset := Offset + 8;
  until Offset > ((Count+7) div 8) * 8;
end; 

function DeCrypt(aStr: string; acKey: string ): string;
var
  ReadBuf,
  WriteBuf : TBlock;
  Key      : TBlock;
  Offset  : Integer;
  Count   : Integer;
  I        : Integer;
  S        : string;
begin
  try
    Key := StrToKey(acKey);
    Des_Init(Key, False);
    
    S := '';
    I := 1;
    repeat
      S := S + Chr(StrToInt('$'+Copy(aStr, I, 2)));
      Inc(I, 2);
    until I > Length(aStr); 

    Offset := 1;
    Count  := Length(S);
    while Offset < ((Count+7) div 8 * 8) do
      begin
      FillChar(ReadBuf, 8, 0);
      Move(S[Offset], ReadBuf, 8);
      Des_Code(ReadBuf, WriteBuf); 

      for I := 0 to 7 do
        begin
        result := result + Chr(WriteBuf[I]);
        end; 

      Offset := Offset + 8;
      end; 

    result := StrPas(PChar(result));
  except
    result := '';
  end;
end; 

end.