100求缩短字符串并能进行还原的方法
我想将以下字符串缩短到20字节并能重新回复到原来的字符串:
/7ub0qVfi4j5fsCyBDzN8kyHDiHlYV+svN5BDXgLL3O3JiHvHzi5cpP0RoJZUwNXDsxD5KGHEZgYLNF6NuCSRzpR4H5I8RlFC4sBSeR2/JTiedhZ63KdO9L1XVf35L6TH/8tlRUBhqoTkSUjCie/A8oRiwMNyQRFfCE4+mOBPy5bbbl279gIxn9Y60St4aSPaCjrkMar+7CbUTDKxliqoVo+4vk3DgmjqbCynrUMFBA=
请问如何实现,代码最好是C#
请高手指教!