Yun Yun signature service is a pioneering electronic signature cloud service solution launched by Digital Authentication 20 15. At that time, with the rise of mobile Internet, applications based on mobile phones, PADs and other terminals emerged one after another. The traditional electronic signature service based on U shield and other media is difficult to meet the application requirements of mobile terminals because of portability and adaptability.

Generally speaking, people borrow money or things, or refer to debits and credits in bookkeeping or balance sheets.