A Verifiable Credential (VC) is a digital version of a credential—such as an ID card, certificate, diploma, or license—that can be issued, presented, and verified securely using cryptography.

Verifiable Credentials are tamper-proof, privacy-respecting, and designed to work without relying on centralized authorities. They are a core component of decentralized identity systems.

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Key Concepts

• Issuer: The entity that creates and signs the credential (e.g., a university, government agency, or company).
• Holder: The person or organization who receives and stores the credential.
• Verifier: The party that checks the authenticity and validity of the credential when it’s presented.

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What’s Inside a Verifiable Credential?

A typical VC includes:

• Information about the subject (e.g., name, ID number, degree earned)
• The DID of the issuer
• A cryptographic proof (e.g., digital signature)
• The context and type of the credential (e.g., “UniversityDegreeCredential”)

Here’s a simplified example:

{
  "@context": ["https://www.w3.org/2018/credentials/v1"],
  "type": ["VerifiableCredential", "UniversityDegreeCredential"],
  "issuer": "did:example:123",
  "issuanceDate": "2024-01-01T00:00:00Z",
  "credentialSubject": {
    "id": "did:example:456",
    "degree": {
      "type": "BachelorDegree",
      "name": "Bachelor of Science in Computer Science"
    }
  },
  "proof": {
    "type": "Ed25519Signature2018",
    "created": "2024-01-01T00:00:00Z",
    "proofPurpose": "assertionMethod",
    "verificationMethod": "did:example:123#key-1",
    "jws": "eyJhbGciOiJF...etc"
  }
}

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Benefits

• Tamper-proof: Thanks to digital signatures, any change to the content invalidates the credential.
• Privacy-respecting: Selective disclosure allows holders to share only the necessary information.
• Instantly verifiable: The verifier can check the signature and issuer DID without contacting the issuer.
• Interoperable: Built on open W3C standards and compatible across platforms.

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Common Use Cases

• Digital ID cards (citizen ID, employee badge)
• Diplomas and professional certifications
• Age verification and access control
• Supply chain compliance credentials
• Health passes and medical certificates

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Relationship with DIDs

Verifiable Credentials rely on DIDs to identify and verify:

• Who issued the credential
• Who holds it
• Which public keys to use for verification

This creates a trust framework where credentials are both portable and verifiable—without centralized intermediaries.

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Let me know if you’d like a visual diagram or flow for this concept, or an explainer tailored for a non-technical audience!