Managing and securing user identities has become increasingly complex in today's digital age. Traditional identity systems often involve central authorities, leading to security vulnerabilities, privacy issues, and inefficiencies. Decentralized Identifiers (DIDs) offer an innovative approach by enabling digital identities to be controlled by their owners rather than centralized organizations. This guide is a two-part series. The first part thoroughly examines DIDs, exploring their benefits, key components, operational mechanics, and use cases. In contrast, in the second part, we will walk you through how a DID can be implemented.

What are DIDs?

Decentralized identifiers (DIDs) represent a novel method of digital identity management. Unlike conventional identifiers that are issued and controlled by central authorities such as governments or corporations, DIDs are designed to be managed by the entities they represent—whether individuals, organizations, or devices. The core idea behind DIDs is to empower users with full control over their own identities, utilizing blockchain technology and cryptographic principles to ensure security and privacy.

DIDs vs. Traditional Identity Systems

DIDs offer several advantages over traditional, centralized identity systems. Before exploring these benefits, let's first examine the flaws of centralized identity systems.

Challenges with Traditional Identity Systems

Traditional identity systems have been the norm for decades, but they come with notable drawbacks. One of the major issues is the risk of a single point of failure. Centralized databases, where identity information is stored and managed, are attractive targets for cyberattacks. If a central authority is compromised, the impact can be extensive, affecting countless users and potentially leading to large-scale data breaches.

Privacy is another concern with centralized systems. Users are often required to provide comprehensive personal details to various organizations, increasing the risk of their information being misused or improperly handled. Additionally, centralized systems can be inefficient, with complex processes for verifying and updating information that can lead to delays and frustrations for users.

Furthermore, traditional identity systems often leave users with limited control over their personal information. The management and verification of identities are handled by third-party organizations, which may not always act in the user's best interest.

How DIDs Solve These Issues

DIDs address the challenges associated with centralized identity systems through their decentralized design. By distributing control across a network, DIDs eliminate the risk of a single point of failure, reducing their vulnerability to large-scale data breaches. 

Self-sovereignty is a key feature of DIDs, giving users full control over their identifiers and credentials. This empowerment reduces dependence on third parties and allows users to manage their identities in a way that aligns with their personal preferences and needs.

Verifiable credentials (VCs) play a crucial role in the DID ecosystem. They are digital statements made by an issuer about a subject that can be verified by a third party through cryptographic methods. VCs are used to convey claims about a user or organization in a way that is both secure and privacy-respecting.

The role of VCs in the DID ecosystem is to provide a means of proving claims made by the DID subject. For example, a digital passport issued as a VC can be used to verify an individual's identity without exposing sensitive personal information. Similarly, academic degrees or professional certifications can be represented as VCs, allowing for secure and verifiable validation of achievements and qualifications.

Structure of a DID

DID Syntax

A DID follows a specific syntax to ensure uniformity and clarity. The standard format for a DID did:<method>:<identifier>. For example, a DID might appear as did:example:123456789abcdefghi. This syntax includes two main components:

  • DID Method: This part of the syntax specifies the DID method used to create, update, and manage the DID. Each DID method defines its own rules and processes for handling DIDs.

  • Identifier: The identifier is a unique string associated with the DID. It ensures that each DID is distinct and can be used to retrieve the corresponding DID document.

Note: The DID document is a crucial component associated with a DID. It contains information about the DID, including authentication methods, service endpoints, and public keys.

Components of a DID Document

A DID document includes several key components that define the characteristics and capabilities of a DID:

  • DID Subject: This is the entity (person, organization, or device) associated with the DID. The DID document provides information about the DID subject and its attributes.

  • Authentication Methods: These methods specify how the DID subject can be authenticated. Common methods include public keys, which are used to prove ownership of the DID and other mechanisms.

  • Service Endpoints: Service endpoints are URLs or other addresses where services related to the DID can be accessed. These endpoints may be blockchains or decentralized repositories.

How DIDs Work

Source: W3C.

  1. Creation and Registration: The process of creating and registering a DID involves several steps. First, a DID method is chosen, which defines the rules and processes for managing the DID. Next, a unique DID identifier is generated based on the chosen method. Once the DID is created, the DID document is published to a decentralized network or blockchain. This publication process involves registering the DID and its associated document, making it accessible for resolution and verification. 

  • Resolution of DIDs: Resolving a DID involves retrieving the DID document associated with it. This process begins with querying a DID resolver, which looks up the DID and returns the corresponding DID document. The DID document provides information about the DID subject and its attributes, enabling verification and interaction based on the DID.

The Role of DID Resolvers and Registries

DID resolvers are systems or services that handle the process of resolving DIDs. They query the decentralized registry or blockchain to retrieve the DID document associated with a specific DID. DID resolvers ensure that the information is accurate and accessible for verification and interaction.

DID registries are databases or ledgers where DIDs and their associated documents are stored. These registries can be blockchain-based or use other decentralized storage mechanisms. DID registries provide the infrastructure needed for managing and accessing DIDs, ensuring that they are secure and available for resolution.

Use Cases of DIDs

Identity Verification

DIDs offer significant benefits for identity verification across various sectors. Digital passports are a prime example of how DIDs can enhance security and convenience. By providing a digital alternative to physical passports, DIDs allow travelers to carry and present their identification in a secure, verifiable format. This approach not only reduces the risk of fraud but also streamlines the verification process at borders and checkpoints.

Driver's licenses are another area where DIDs can be applied. Digital driver's licenses, represented as VCs, can be used to verify an individual's identity without the need for physical cards. This digital approach offers improved security and convenience, reducing the risk of identity theft and streamlining interactions with law enforcement and other authorities.

Access Control

DIDs can also improve access control systems by providing secure and verifiable credentials. Smart locks, for example, can use DIDs to grant or restrict access to physical spaces based on authenticated credentials. 

In corporate networks, DIDs can be used to manage employee access to systems and resources. By leveraging verifiable digital credentials, organizations can ensure that only authorized personnel have access to sensitive information and systems. This approach not only improves security but also reduces the administrative overhead associated with managing access permissions.

Supply Chain Management

In supply chain management, DIDs offer a powerful tool for tracking and verifying products. By assigning DIDs to products and using VCs to record information about each step in the supply chain, organizations can ensure the authenticity and origin of products. This approach enhances transparency and accountability, allowing stakeholders to verify compliance with regulatory standards and quality requirements.

Tracking products through the supply chain using DIDs also helps to prevent fraud and counterfeiting. By providing a secure and verifiable record of each transaction and movement, DIDs ensure that products are genuine and meet the expected standards.

Conclusion

Decentralized identifiers (DIDs) represent a significant advancement in digital identity management. By providing a decentralized, user-centric approach, DIDs address many of the challenges associated with traditional identity systems, including security vulnerabilities, privacy concerns, and inefficiencies. The ability to control and manage identities independently, combined with the use of verifiable credentials and secure authentication methods, makes DIDs a powerful tool for a wide range of applications. 

References & Further Reading