4.1. Definition and Importance of DID
A DID (Decentralized Identifier) is a new form of digital identity identifier generated on the basis of distributed-ledger technology (DLT) or another distributed system. Unlike existing centralized identity systems (e.g., website logins, national identification numbers, etc.), a DID is not subordinate to any specific institution or service provider; it allows an individual to create, manage, and control their own identity information themselves.
In the PRODAO ecosystem, DIDs are very important for the following reasons.
- Securing data sovereignty: A DID is a core tool that allows individual experts to exercise full ownership and control over their own data. They can clearly control who can access which information and when.
- Strengthening privacy: A DID makes it possible to authenticate identity or prove the validity of specific information without directly exposing an individual's sensitive information, thereby protecting privacy. It enables “selective disclosure,” sharing only the necessary information.
- Interoperability: A DID can smoothly interconnect with services and applications outside the PRODAO ecosystem. This allows PRODAO experts to use their identity and data across diverse Web3 environments.
- Reliability and transparency: Because a DID recorded on the blockchain cannot be tampered with, and the change history of identity information can be verified transparently, reliability is increased.
- Intermediary-free authentication: It enables direct identity authentication between individuals or between services without a centralized intermediary, reducing unnecessary cost and complexity.
4.2. Structure and Operation of the PRODAO DID System
The PRODAO DID system has the following key components and mode of operation.
- DID (Decentralized Identifier): A unique identifier for each individual expert, generated on the PRODAO Mainnet. Beyond an expert's verified credentials (VCs), degrees, records of participation in specific projects, and major achievements, it can also be issued as an NFT—a unique and immutable digital asset representing ownership of an expert's original creations such as unique digital art, music, design, 3D models, and other works.
- These NFTs are strongly linked to the expert's DID, proving that the expert is the actual creator and leaving an immutable on-chain record of the authenticity and ownership of the digital asset. This composes the expert's profile in a richer and more trustworthy way and protects the creator's rights.
- Use: NFT-ized creations and credentials are used to raise an expert's trustworthiness in employment, collaboration, and project participation, permanently recording the expert's achievements and creative activities in a tamper-proof form. This becomes an important element that represents an expert's reputation and trustworthiness within the PRODAO ecosystem in a visual and verifiable form.
- DID Document: A JSON-LD document containing metadata linked to a DID. This document includes the public key, service endpoints, and information related to “Verifiable Credentials” by which the DID owner can prove other claims in a cryptographic manner. DID documents are mainly stored off-chain, while the DID itself is recorded on-chain.
- Verifiable Credentials (VC): Data in which a specific institution (e.g., a university, a credential-issuing body, an employer) issues, encrypts, and signs an individual's identity information (e.g., degree, certification, career) in a digital manner. This VC is managed directly by the DID owner and, when necessary, can be presented to another party in the form of a Presentation to prove one's claims.
- Issuer: The entity that issues the VC (e.g., the PRODAO platform, an educational institution, a company).
- Holder: The individual (expert) who has a DID and owns and manages VCs.
- Verifier: The entity that receives and confirms the validity of a VC (e.g., a service provider, another expert).
How It Works
- DID creation and registration: The expert creates their DID on the PRODAO Mainnet and registers it on the blockchain.
- VC issuance: A university issues a graduation certificate as a VC and links it to the expert's DID. Alternatively, the PRODAO platform may issue a VC for an expert's specific activity (content creation, community contribution, etc.).
- VC storage and management: The expert (holder) stores their VCs in a personal wallet or distributed storage that securely manages them.
- VC Presentation: When an expert uses a specific service (e.g., a professional-knowledge-sharing service, a job platform), they selectively present the information required by that service (the verifier) in the form of a VC. At this time, only the minimum necessary information—not the individual's entire information—may be transmitted in encrypted form.
- VC verification: The service (verifier) verifies the validity of the presented VC (the validity of the issuer's signature, whether the content of the VC has been tampered with, etc.) through the DID information recorded on the blockchain.
4.3. DID-Based Data Sovereignty Management and Use Cases
PRODAO's DID system focuses on strengthening experts' data sovereignty.
- Consent-based data use: When an expert shares or uses data linked to their DID, explicit consent must always be obtained. Through smart contracts, the conditions for data access and use are clearly set, and the expert can withdraw their consent at any time.
- Selective information disclosure: Among the numerous pieces of information linked to their DID (education, career, field of expertise, project participation history, activity data, etc.), an expert can selectively disclose only the necessary parts. For example, when they wish to prove only a specific part of their career for participation in a particular project, they can keep other personal information private.
- Data monetization: Expert data managed on a DID basis can create value and be rewarded within the PRODAO ecosystem. For example, an expert can consent to providing data for AI-model training and receive PROD token rewards for it.
- Personalized services: Anonymized data collected with the expert's consent is analyzed through AI models and used to provide personalized services such as content recommendations, collaboration-opportunity matching, and learning-path suggestions tailored to the individual's interests and field of expertise.
- Transparency of data-use history: Through the DID system, an expert can transparently verify records of when, to whom, and for what purpose their data was used.
4.4. DID Security and Privacy Protection
PRODAO's DID system aims for the highest level of security and privacy protection.
- Encryption technology: All sensitive data is stored and transmitted using strong encryption technology. Through public-key encryption, the confidentiality and integrity of data are secured.
- Distributed storage: Sensitive data linked to a DID document is stored in encrypted form in a distributed storage system such as IPFS rather than on a central server. This removes single points of failure and minimizes the risk of data breaches.
- Access control: Through a sophisticated smart-contract-based access-control mechanism, the DID owner can finely set and manage access rights to their own data.
- Non-deterministic DIDs: PRODAO designs DIDs so that they do not include information that can identify a specific individual, and it strengthens privacy by applying the concept of “pairwise DIDs,” generating diverse DIDs as needed and using each only for a specific activity.
- Auditability: The DID change history recorded on-chain and the hash values of off-chain data provide auditability, raising the transparency and reliability of the system.
- Continuous security audits: The smart contracts and protocols related to the DID system undergo regular external security audits to identify and remediate potential vulnerabilities.