Error en Función Encriptar y Desencriptar

[webmasterplc]

Código Delphi [-]
unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs;

type
  TForm1 = class(TForm)
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
Const CRIPTPASSWORD   = 9281711.00;

Var   KeyResult       : String;

Function CriptClave ( Signo:ShortInt;Nombre : Str255; Cripto: Real) : String;
Var L,I: Byte;
    S: String;
    Temp: Array[0..255] Of Byte Absolute Nombre;
Begin
 Str(Trunc(Cripto),S);
 L:=Length(Nombre);
 While Length(S)Do
  S:=S+S;
 For I:=1 To L Do
   Temp[i]:=Temp[i] + (Ord(S[i])-48)*SigNo;
 CriptClave:= Nombre;
End { CriptClave };
end.