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)

    procedure FormCreate(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

const CKEY1 = 53761;

      CKEY2 = 32618;

function EncryptStr(const S :WideString; Key: Word): String;

var   i          :Integer;

      RStr       :RawByteString;

      RStrB      :TBytes Absolute RStr;

begin

  Result:= '';

  RStr:= UTF8Encode(S);

  for i := 0 to Length(RStr)-1 do begin

    RStrB[i] := RStrB[i] xor (Key shr 8);

    Key := (RStrB[i] + Key) * CKEY1 + CKEY2;

  end;

  for i := 0 to Length(RStr)-1 do begin

    Result:= Result + IntToHex(RStrB[i], 2);

  end;

end;

function DecryptStr(const S: String; Key: Word): String;

var   i, tmpKey  :Integer;

      RStr       :RawByteString;

      RStrB      :TBytes Absolute RStr;

      tmpStr     :string;

begin

  tmpStr:= UpperCase(S);

  SetLength(RStr, Length(tmpStr) div 2);

  i:= 1;

  try

    while (i < Length(tmpStr)) do begin

      RStrB[i div 2]:= StrToInt('$' + tmpStr[i] + tmpStr[i+1]);

      Inc(i, 2);

    end;//delphitop.com

  except

    Result:= '';

    Exit;

  end;

  for i := 0 to Length(RStr)-1 do begin

    tmpKey:= RStrB[i];

    RStrB[i] := RStrB[i] xor (Key shr 8);

    Key := (tmpKey + Key) * CKEY1 + CKEY2;

  end;

  Result:= UTF8Decode(RStr);

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

caption:=DecryptStr(EncryptStr('中国',100),100);

end;

end.