What is Digital Identity#
Identity is an essential characteristic for every individual. In traditional society, we use a series of physical materials to prove "I am who I am". These materials not only include proofs of who we are, such as identification cards, but also proofs of our social relationships and behaviors, such as marriage certificates, driver's licenses, and diplomas, all of which are encompassed in the concept of identity.
In the era of the Internet, physical materials have been replaced by electronic information, giving rise to digital identity. Digital identity is an online identifier, with its core being the provision and verification of identity information to prove "I am who I am".
Identity in Web2.0#
In Web2.0, in order to use the functionalities provided by platforms, users must authorize centralized third-party platforms to manage a large amount of data. As a result, these centralized companies are granted significant power and influence over data and content permissions, owning the rights to user data and all user-generated content. This means that user identity and data are under control. Massive user data has become a tool for platforms to profit, and many individuals who should enjoy the convenience of the Internet are forced to become "data laborers", serving platform algorithms. Undoubtedly, such acts of disrespect towards user data and identity violate the spirit of the Internet.
At the same time, the monopolistic and territorial nature of Web2.0 platforms has solidified social graphs and user relationships, making it difficult for users to migrate. If the original platform becomes unusable for various reasons, the process of moving your friends to a new platform becomes extremely cumbersome and complex.
The root cause of all this is the lack of corresponding identity mechanisms. The data of the original platform does not belong to the users themselves, and you still cannot prove the fact that "I am who I am".
Based on this situation, in the era of Web3.0, it has become a trend to attribute personal identity content to the users themselves and give users ownership of their own identity data. This is where the solution of self-sovereign identity (SSI) comes into play.
What is Self-Sovereign Identity#
Self-sovereign identity (SSI) refers to users having complete control over their own identity data. It is the center of identity management, with independent control, security, and full portability, not being tied to any specific site or region.
Blockchain provides a distributed trust environment, which is a necessary technology for achieving self-sovereign identity. The core idea of blockchain-based self-sovereign identity is to create a globally unique identity identifier called DID (Decentralized Identifier), which has high availability, resolvability, and encryption verifiability.
What is DID#
DID (Decentralized Identifier) is a decentralized identity system that derives from and evolves from traditional centralized identity. It refers to the ownership, control, and management of one's own digital identity by individuals or organizations, removing intermediaries. The DID system mainly consists of the foundational layer of DID identifiers, DID documents, and the application layer of verifiable credentials (VC).
- DID Identifier: A globally unique identity identifier, similar to a person's identification card or account.
- DID Document: A simple document describing how to use the DID.
- Verifiable Credentials (VC): The DID document itself cannot be associated with the user's real identity information. VC is needed to achieve this and is the value of the entire system. VC is similar to a digital certificate and serves as proof of a user's identity.
DID itself is just an identity identifier and does not need to be stored on the blockchain. However, by combining blockchain with DID, users can have full control over all their identity information and achieve a single identity, truly realizing self-sovereign identity and data autonomy, protecting the rights and data privacy of users. The image below illustrates this:
"It can be said that self-sovereign identity (SSI) encompasses decentralized identity (DID)."
DID, as a foundational infrastructure, derives more value not from itself, but from the series of data it generates.