Verifiable Credentials (VCs), ZKPs, and Data Minimization

The foundation of privacy in UIID is Data Minimization: the principle that you should only share the absolute minimum amount of information required to complete a task. This is powered by Verifiable Credentials (VCs) and Zero-Knowledge Proofs (ZKPs).

What are Verifiable Credentials (VCs)?

A VC is a secure, digital proof of a claim about you, issued by a trusted organization (Issuer) and stored in your private Identity Vault.

Traditional Document

UIID Verifiable Credential (VC)

Benefit of VC

Physical Passport

VC: "Citizenship Verified: TRUE"

Prove nationality without showing your picture or document number.

Physical Driver's License

VC: "Age is greater than 21: TRUE"

Prove your age without revealing your birth date.

Employment Contract

VC: "Currently Employed: TRUE"

Prove current employment without revealing your salary or employer.

The Role of Zero-Knowledge Proofs (ZKPs)

ZKPs are the cryptographic backbone that ensures Data Minimization. A ZKP allows you to prove a statement is true without revealing any information that supports the statement.

Use Case: Accessing Age-Restricted Content

  1. The Request: A website wants to verify you are over 18.

  2. Traditional Way: You upload a copy of your ID, revealing your name, address, and exact birth date (massive data over-sharing).

  3. UIID Way (using ZKP): You present your "Verified Age" VC from your Vault. The Vault instantly generates a ZKP that simply returns: "User is over 18: TRUE."

The website gets the proof it needs (compliance), but your birth date and full identity are never revealed, collected, or stored. Your identity is unassailable.

Revocation and Status

If you lose your Core ID or an Issuer revokes a credential (e.g., a degree), the change is instantly registered on the DLT as a Status Proof. This ensures that VCs remain trustworthy globally while still protecting your privacy by only publishing the status, not your PII.