字符串加密错误dcpcrypt Lazarus

Question

有人可以说请问为什么这不会加密/解密字符串？它只会隐藏它们，但无法回复书面文字：

procedure TForm1.btnEncryptClick(Sender: TObject);
  var
    i: integer;
    Cipher: TDCP_rc4;
    KeyStr: string;
  begin
    KeyStr:= '';
    if InputQuery('Passphrase','Enter passphrase',KeyStr) then  // get the passphrase
    begin
      Cipher:= TDCP_rc4.Create(Self);
      Cipher.InitStr(KeyStr,TDCP_sha1);         // initialize the cipher with a hash of the passphrase
      for i:= 0 to Memo1.Lines.Count-1 do       // encrypt the contents of the memo
        Memo1.Lines[i]:= Cipher.EncryptString(Memo1.Lines[i]);
      Cipher.Burn;
      Cipher.Free;
    end;
  end;

  procedure TForm1.btnDecryptClick(Sender: TObject);
  var
    i: integer;
    Cipher: TDCP_rc4;
    KeyStr: string;
  begin
    KeyStr:= '';
    if InputQuery('Passphrase','Enter passphrase',KeyStr) then  // get the passphrase
    begin
      Cipher:= TDCP_rc4.Create(Self);
      Cipher.InitStr(KeyStr,TDCP_sha1);         // initialize the cipher with a hash of the passphrase
      for i:= 0 to Memo1.Lines.Count-1 do       // decrypt the contents of the memo
        Memo1.Lines[i]:= Cipher.DecryptString(Memo1.Lines[i]);
      Cipher.Burn;
      Cipher.Free;
    end;
  end;

这是Lazarus的dcpcrypt库。代码编译时没有错误，但在writeln过程中没有正确的结果。谢谢你的帮助。