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What Is ZelfProof? Privacy-Preserving Biometric Identity Explained
ZelfProof is a privacy-preserving digital signature derived from your face—without storing biometrics. Learn how zero-knowledge proof of personhood works for wallet recovery, passwordless login, and credential encryption.
Miguel Treviño•
TL;DR:
- ZelfProof is a cryptographic identity derived from your face—but no biometric images or patterns are ever stored.
- Face data is converted into a binary representation that feeds public key generation for encryption, signatures, and secure document management.
- Unlike traditional KYC, ZelfProof enables proof of personhood without centralized databases or exposing personal data.
- Use cases: wallet recovery, passwordless authentication, credential encryption, and offline verification via QR codes.
- Built with TensorFlow.js and liveness detection; optional password entropy layer for stronger keys.
- IPFS stores your ZelfProof decentralized—no single point of failure. Critical for the Agentic Web: it separates verified humans from autonomous agents.
The Problem with Traditional Identity
Most identity systems today are built on a trade-off: prove you are you, and in exchange, hand over your data. Governments and companies store your face, your fingerprints, your documents. One breach—and we have seen many—and that data is gone forever.
ZelfProof flips the script. You prove you are a unique human without handing over anything that can be stolen or replayed. Your face is used once to generate a cryptographic identity. The face data itself is never stored.
How ZelfProof Works (Without Storing Your Face)
ZelfProof turns your face into a privacy-preserving digital signature in three conceptual steps:
- Capture: Your face is analyzed in real time using on-device models (TensorFlow.js, face-api). Liveness detection ensures a real person is present—not a photo or a deepfake.
- Transform: Face data is converted into a non-biometric binary representation. This is not a template of your face; it is a derived value that cannot be reverse-engineered back to your image.
- Derive: That representation, optionally combined with a password for extra entropy, is used to generate a cryptographic public key. You get encryption, digital signatures, and secure document management—all tied to "you" without storing biometrics.
Because no biometric template or image is stored, a breach of the system cannot leak your face. You can regenerate the same logical identity on a new device by proving your face again; the math is deterministic, the secret is you.
ZelfProof vs. Traditional KYC
| Traditional KYC | ZelfProof |
|---|---|
| Centralized database of faces/documents | No central store of biometrics |
| One breach exposes everyone | No face data to steal |
| Same identity across all services (tracking) | You choose where and when to prove personhood |
| Vendor lock-in | Your keys, your identity, portable |
ZelfProof gives you proof of personhood—the assurance that a unique human is behind an action—without the privacy cost of classic identity systems.
Use Cases: Where ZelfProof Shines
- Wallet recovery: Restore access to your crypto by proving your face. No seed phrase scribbled on paper; no single password to forget.
- Passwordless login: Sign into apps and services with a face check. No passwords to phish or leak.
- Credential encryption: Lock passwords, payment cards, and notes with a key derived from your face. Only you can decrypt.
- Offline verification: Export your ZelfProof as a QR code for validation without the internet—useful in low-connectivity or high-privacy scenarios.
- Decentralized backup: Store your ZelfProof on IPFS. No single company controls your identity; you own the data.
Technical Architecture (High Level)
- Biometric pipeline: Camera → face detection → liveness check → binary representation. All processing can run on-device.
- Optional password layer: Users can add a password to the derivation for additional entropy and stronger keys.
- Public key cryptography: The derived key material supports standard operations: encrypt/decrypt, sign/verify. Compatible with existing PKI and key-agreement patterns.
- Storage: ZelfProof metadata can be published to IPFS so that you—and only you—can recover or present your identity from the decentralized web.
Why This Matters for the Agentic Web
As AI agents execute trades, post content, and transact on-chain, the question "is this a human or a bot?" becomes critical. ZelfProof is proof of personhood: a cryptographically strong, privacy-preserving way to show that a unique human is behind an action. It does not rely on passwords (bots can steal those) or 2FA (sim-jacking and phishing exist). It ties the action to a live human face, without storing that face anywhere.
For protocols that need human-only access—DeFi, airdrops, governance—ZelfProof offers a clear boundary: verified human vs. unverified agent.
Get Started
ZelfProof is built into the Zelf Extension. Create your ZelfProof, link it to your wallet and credentials, and never lose access to your crypto—without losing your privacy.