What is DID?
DID (Decentralized Identifier) is a digital identity identifier based on blockchain or distributed ledger technology. Its core concept is to allow users to truly own and control their identity information, without relying on traditional centralized platforms such as Google, Facebook, or government databases. In the Web2 world, identity verification often depends on third-party platforms, which act as gatekeepers and also own the data. The emergence of DID is intended to break this model and return identity to the users.
The core feature of DID
The reason DID has become a hot topic in the Web3 world lies in its key characteristics:
- Self-sovereign
 Users can manage their own identification data without relying on third-party institutions.
- Decentralized
 Identification information is stored on a decentralized network rather than a single server, ensuring the security and transparency of the data.
- Verifiable
 Through encryption technology and verification mechanisms, identification information can be securely verified to ensure authenticity and reliability.
- Privacy-preserving
 DID allows users to provide only the necessary information when verifying their identification, rather than complete personal data, thus protecting users’ privacy.
The operating principle of DID
DID is not just a simple identification code, but a system that combines the DID Document and Verifiable Credentials.
- DID: A unique identification code, formatted like did:example:123456789abcdef.
- DID Document: Describes the public key, verification methods, and service endpoints of the DID owner.
- Verifiable Credentials (VC): Provided by trusted issuers to prove certain attributes, such as diplomas, memberships, driver’s licenses, etc.
The verification process is roughly as follows:
- The user holds DID and VC.
- Verify the direction of the blockchain query DID Document.
- Verify the authenticity of the certificate through the public key.
- Complete identification.
Application scenarios of DID
The potential of DID is not limited to the financial or cryptocurrency sector; it can be applied to almost all scenarios that require identification.
- Web3 DApp Login: Use DID to replace traditional account passwords for login, allowing users to securely access decentralized applications across platforms.
- Decentralized Finance (DeFi) KYC: DID can be combined with verifiable credentials to complete the KYC process while protecting privacy.
- NFT and Digital Asset Verification: DID can prove the true owner of the NFT, preventing counterfeit transactions.
- Educational and professional certificates: academic degrees, professional qualifications, etc. can be stored in the DID in the form of VC for quick verification.
- Online Voting and Governance: In DAOs and online elections, DID can prevent multiple voting and bot manipulation.
- Famous DID protocols and projects: By 2025, DID technology has gradually matured, with some well-known projects and protocols including:
Advantages and Challenges of DID
advantage
- Truly control personal identification information.
- Improve cross-platform interoperability.
- Reduce the risk of data leakage.
- Complies with privacy regulations (such as GDPR).
challenge
- The popularity is still low, and the ecosystem is not fully mature.
- Users need to manage their keys themselves; if lost, they cannot be recovered.
- Interoperability between different DID systems is still under development.
summary
Decentralized Identity (DID) is not an unattainable concept; it is a foundational technology that is changing the rules of the digital world. It not only allows us to regain control over our own identification but also enables true self-sovereignty in the Web3 ecosystem. With the development of technology and the expansion of its applications, DID will play an important role in the future digital society.