Encode Decode Base64 String On Delphi

Here We go.. Firt using encode - decode base64 for security string for saving at registry this alternative so simple and secure.

const  
  Codes64 = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/';  
 function Encode64(S: string): string;  
 var  
  i: Integer;  
  a: Integer;  
  x: Integer;  
  b: Integer;  
 begin  
  Result := '';  
  a := 0;  
  b := 0;  
  for i := 1 to Length(s) do  
  begin  
   x := Ord(s[i]);  
   b := b * 256 + x;  
   a := a + 8;  
   while a >= 6 do  
   begin  
    a := a - 6;  
    x := b div (1 shl a);  
    b := b mod (1 shl a);  
    Result := Result + Codes64[x + 1];  
   end;  
  end;  
  if a > 0 then  
  begin  
   x := b shl (6 - a);  
   Result := Result + Codes64[x + 1];  
  end;  
 end;  
 function Decode64(S: string): string;  
 var  
  i: Integer;  
  a: Integer;  
  x: Integer;  
  b: Integer;  
 begin  
  Result := '';  
  a := 0;  
  b := 0;  
  for i := 1 to Length(s) do  
  begin  
   x := Pos(s[i], codes64) - 1;  
   if x >= 0 then  
   begin  
    b := b * 64 + x;  
    a := a + 6;  
    if a >= 8 then  
    begin  
     a := a - 8;  
     x := b shr a;  
     b := b mod (1 shl a);  
     x := x mod 256;  
     Result := Result + chr(x);  
    end;  
   end  
   else  
    Exit;  
  end;  
 end;