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Verifiable Credentials (VCs)

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The W3C Standard for SSI

Verifiable Credentials (VCs) are a fundamental component of modern digital identity systems or Self Sovereign Identity (SSI) system and W3C standard, revolutionizing the way individuals and organizations share and verify information. VCs enable the issuance, presentation, and verification of digital credentials in a secure, privacy-preserving, and interoperable manner. This wiki page provides an in-depth exploration of Verifiable Credentials, their technical intricacies, core concepts, and their pivotal role in the digital identity landscape. Additionally, we’ll discuss how Extrimian leverages VCs in its products and solutions to empower users with secure and trusted digital credentials.

Technical Aspects

What is a Verifiable Credential?

Verifiable Credentials are digital attestations, claims, or statements made by issuers about subjects (individuals, entities, or devices) that can be cryptographically verified. They serve as a means to express a wide range of claims, such as educational degrees, professional certifications, identity attributes, and more, in a digital format. VCs are designed to be tamper-evident and privacy-enhancing, allowing subjects to share only the necessary information without disclosing sensitive data.

Verifiable Credentials for Decentralized Digital Identity circuit

VC Data Model

The W3C Verifiable Credentials Data Model specification defines the structure and semantics of Verifiable Credentials. It includes essential components such as:

  • Credential: The primary building block that represents an individual VC. It contains claims and metadata about the subject and the issuer.
  • Issuer: The entity that issues the credential, digitally signing it to prove its authenticity.
  • Subject: The entity about whom the credential makes claims. This could be an individual, organization, or device.
  • Claim: The specific statement or piece of information made by the issuer about the subject.

Verifiable Credential Format

VCs can be expressed in various formats, including JSON-LD (JSON for Linked Data), which provides a structured, interoperable way to represent credentials. JSON-LD allows VCs to be easily shared, validated, and linked to other data sources.

Structure of Verifiable Credentials

A typical Verifiable Credential consists of several key elements: 

Source: https://www.w3.org/TR/vc-data-model/

  1. Context: The context provides information about the vocabulary and terms used within the credential. It ensures semantic interoperability when interpreting the data.
  2. Type: The type field specifies the type of credential, such as a diploma, driver’s license, or membership card.
  3. Issuer: This field identifies the entity that issued the credential. It includes information about the issuer’s DID (Decentralized Identifier) and, optionally, a verification method.
  4. Subject: The subject is the entity to whom the credential pertains. It includes information about the subject’s DID and attributes related to the claim.
  5. Claim: The claim is the actual statement being made in the credential. It can be a simple statement like “Has a Bachelor’s Degree” or a more complex assertion.
  6. Proof: The proof section contains cryptographic proofs that validate the authenticity and integrity of the credential. It includes digital signatures or Zero Knowledge Proofs (ZKPs) to verify the issuer’s authority.
Systematization of Knowledge for Decentralized Identities & Verifiable Credentials

Building a Verifiable Credential

Building a Verifiable Credential involves several steps:

  1. Issuer Creation: The issuer generates a DID, establishing its identity in the decentralized network. It also generates a key pair for cryptographic operations.
  2. Credential Creation: The issuer assembles the Verifiable Credential by defining the context, type, issuer, subject, claim, and any necessary proof.
  3. Signing: The issuer digitally signs the credential using its private key, creating a verifiable proof of the credential’s authenticity.
  4. Presentation: The subject presents the Verifiable Credential to a verifier, either directly or through a third-party service, based on the verifier’s request.
  5. Verification: The verifier checks the credential’s integrity by verifying the digital signature or validating the proof. If valid, the verifier trusts the claim made in the credential.

Core Concepts


One of the core principles of VCs is privacy preservation. Subjects have control over what information they share, allowing them to present only the necessary claims for verification without revealing extraneous details. This selective disclosure enhances privacy and minimizes the risk of identity-related breaches.

Trust and Security

The cryptographic signatures and proofs associated with VCs ensure trust and security in the credentialing process. Issuers’ digital signatures verify the authenticity of the credentials, while cryptographic techniques like Zero Knowledge Proofs (ZKPs) can be employed to validate claims without exposing the underlying data.


VCs are designed to be highly interoperable across different systems and services. This interoperability streamlines the exchange of credentials between various entities, making it easier to verify claims across a wide range of applications and domains.

Extrimian’s Utilization of Verifiable Credentials

Extrimian recognizes the immense value of Verifiable Credentials in enhancing digital identity solutions. VCs are an integral part of Extrimian’s commitment to empowering individuals and organizations with secure and trusted digital credentials.

Extrimian’s Products: Extrimian incorporates Verifiable Credentials in its suite of products to provide users with a secure and efficient way to manage and share their digital credentials. Whether it’s academic diplomas, professional certifications, or identity attributes, Extrimian’s products leverage VCs to ensure the credibility and integrity of digital credentials.

Learn more about this SSI w3c standard and technology with the Extrimian Academy in this lesson: Verifiable Credentials -VCs-

Sources and References

For more technical information and resources on Verifiable Credentials (VCs), you can refer to the following sources:

Verifiable Credentials (VCs) are a cornerstone of modern digital identity systems, empowering individuals and organizations with secure and privacy-preserving digital credentialing. They play a vital role in Extrimian’s vision of a trusted and user-centric digital identity ecosystem.