Nowadays, the Internet is ubiquitous as nearly 70% of the world’s population uses the Internet in their daily lives. Digital life and real life are blended with a variety of Internet applications and services through computer devices. Users can instantly interact with different individuals or companies distributed around the world all the time. During the interaction, the convenience and importance of digital identities for linking and mapping of real identities online and the automatic verification and process of digital identities are becoming increasingly significant. This time’s special feature will be divided into two parts, the first will talk about the origin and evolution of identity and digital identity, and the second will focus on the new generation of PlatON DID (Decentralized Identity) with blockchain and cryptography technology as the core.

Definition of Identity

When talking about identity, people usually quickly associate it with a series of documents that prove “you are you”, such as your ID card, household register, residence permit, driver’s license, etc. In today’s society, without an identity, one cannot have a bank account, receive education, or access social benefits, and will be shut out from relevant political activities.

In the International Standards Organization, identity is defined as a “set of attributes related to an entity”, which can be a person or an institution. The following is a brief description of entities from the perspective of attributes, relationships, and agents respectively.

• Attributes: physical and social attributes of the entity, e.g., a person’s birth, education, work history, etc;
• Relationships: social relations of an entity, e.g., country of affiliation, the company of affiliation, relatives, and friends;
• Agents: attorneys and real estate agents commissioned by the entity;

The identity is formed by the statements of the different participants and the dynamic behavior of the verifiable statements.

• Statement: this can be a claim or assertion of identity by an individual or organization, e.g., “My name is Tie Dan, born on June 18th, 1997, Chinese”.
• Proof: A document in some form that provides evidence for a statement. For example, an individual’s passports, birth certificates, etc.
• Verification: A third party confirms that the statement is true based on the record. For example, a university can prove that an individual has studied at the school and earned a degree.

Evolution of Digital Identity

Nowadays, the Internet is ubiquitous as nearly 70% of the world’s population uses the Internet in their daily lives. Digital life and real life are blended with a variety of Internet applications and services through computer devices. Users can instantly interact with different individuals or companies distributed around the world all the time. During the interaction, the convenience and importance of digital identities for linking and mapping of real identities online and the automatic verification and process of digital identities are becoming increasingly significant.

In the early days of the Internet, there was no design for digital identity in the underlying protocols, and a famous cartoon named “On the Internet, no one knows you’re a dog” made fun of this Internet loophole, which vividly depicted that in the early days of the Internet, people could indulge themselves and surf the Internet anonymously, enjoying the pleasures of the Internet.

First-Generation Digital Identity

The earliest digital identity on the Internet is the traditional account model that we are familiar with. When using various applications and services such as forums, games, e-commerce, etc., you need to register an account in the system and then log in with the account to use the services. In this process, you provide your identity information to each service provider, then the service provider assigns you with an ID, which you would then use, and all the data will be recorded on the data server of the service provider. At the time of registration, the ID and data used are also legally attributed to the service provider according to the signed agreement.

The traditional account model poses a problem in that each network application service requires you to create an account, and the increasing numbers of accounts are not only cumbersome to manage but also are often forgotten.

Second-Generation Digital Identity

To solve the inconvenience of managing multiply accounts that existed in the first generation of digital identity, the second generation is created: “One Click Login”. After authorization by the user, the user’s relevant account data is transmitted to the central system of a single login service provider. The commonly accepted one-click login methods in the market include WeChat login, Facebook login, etc. It is very convenient to log in to various platforms with one click, but at the same time, it also reveals some problems:

Privacy leak:

The use of one-click login poses the risk of user privacy data leakage. Facebook, as the world’s largest social network platform, has a volume of daily active users that is equivalent to 1/5 of the world’s population. Many users who use Facebook to log in to external servers face the risk of privacy leakage, because Facebook does not protect properly the privacy data of its users, instead it shares all kinds of social information of its users to other parties, resulting in the leakage of 87 million users’ information in only one year.

Third-generation Digital Identity

Whether it is the traditional account of the Internet or the one-click login, the digital identities of both models, from a technical and legal point of view, do not belong to the users themselves and are out of the control of the users. For example, the Twitter account registered by former President Donald Trump belongs to him nominally, but the control is still in the hands of the operator. In addition, the private data of the account, also can not be controlled by the user himself, more often than not, the user’s privacy data may have been leaked by the person in control. As the pain points of user data leakage and misuse become increasingly prominent, there is a growing need and trend to enable users to own and control their own identity in the digital world, while safely storing and soundly protecting the digital identity information.

Through the analysis, it can be concluded that the first and second generation of digital identities is facing the following two problems:

• Individual users do not actually own their own identity;
• Individual account identities are not interconnected.

In order to solve the above problems, the third generation of digital identity, Decentralized Identity (DID for short), was born. DID essentially refers to a set of identities that are completely decentralized and enables individuals or organizations to have full ownership, management, and control of their own digital identities and data. That is, the user’s identity information is not stored on the server of an organization or controlled by an organization, but is distributed over many nodes on the network, and is entirely under the control of the user.