Digital identity refers to a public key that condenses real identity information into a digital code that can be queried and identified through the network and related equipment. Digital identity can have a comprehensive portrayal of users by integrating new information. For example, the national ID card has a unique number, and the number itself does not have information and is only used for personal authentication. However, based on the number, we can fill in information with mobile phone numbers, photos, etc., to improve the content of digital identity. And due to the popularization of social software nowadays, e-mails, personal information, photos, IP locations, etc., may be at risk of being stolen. Share messages on Facebook, Twitter, or blogs, share photos, etc., although It’s very convenient, but you can’t control those messages, photos, how many times they are shared, or who they share with. So you may expose the message to strangers or even bad people by accident. Although digital identity is more convenient than paper itself, there are many risks