GhostBio | Zero-Knowledge Selective Disclosure Protocol

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  Owner Desk: Unlocked physical venue door code and emergency Off-Air Hard Deactivate controls.

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  Owner Control Desk: Adding new ZK-gated links and customizing tier access requirements.

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  Organizer Terminal: Real-time pass metrics, targeted attendee upgrades, and batch revocation.

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  Owner Security Desk: Anonymized ZK audit stream logging real-time verification events.

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  Visitor View: Sending an anonymous ZK connection request without revealing wallet ID.

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  Visitor Card: Active connection established state showing verified selective disclosure access.

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  Visitor Card: General Pass presented; selectively unlocks tier-1 direct signal contact link.

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  Visitor Card: VIP Investor Pass presented; unlocks confidential pitch deck in zero-knowledge.

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  Owner Security Desk: ZK connection inbox, privacy metrics, and real-time audit stream.

Inspiration

Physical business cards end up in the trash, and single-use event apps force attendees to surrender their personal contact info, financial history, and social profiles to third parties. I built GhostBio to transform Web3 networking through rational privacy, giving users complete control over their digital footprint with a permanent, privacy-preserving zero-knowledge bio card and contact management protocol.

What It Does

GhostBio is a ZK-native selective disclosure profile and ephemeral event pass protocol built on Midnight Network:

• Selective Disclosure Profile: Public links (like GitHub or X) remain open, while sensitive channels (direct signals, pitch decks) are ZK-gated behind tier commitments (General, VIP, Speaker).
• Zero-Knowledge Access: Visitors present an event pass key evaluated locally via Midnight's proof server. Access is verified on-chain without revealing the visitor's wallet address or identity.
• Owner Control Desk: Profile owners manage incoming connection requests, follow contacts, and trigger an immediate off-air "Hard Deactivate" blackout mode if links are compromised.
• Organizer Terminal & GDPR Ephemerality: Event organizers issue ZK venue passes and execute post-event batch key revocations, ensuring attendee data auto-expires to satisfy enterprise GDPR requirements.

How I Built It

• Smart Contracts: Written in Compact (bboard.compact), compiling natively into ZKIR bytecode, TypeScript bindings, and proving/verifying keys.
• ZK Proof Execution: Integrated with a local Midnight Proof Server Docker container (http://localhost:6300) evaluating 32-byte padded secret vectors.
• Frontend: Built with React, Vite, and Tailwind CSS to deliver a unified multi-role dashboard.
• Architecture: Structured as a monorepo workspace spanning contract, api, bboard-cli, and bboard-ui.

Challenges I Overcame

Strict byte-length padding constraints (Bytes<32>) in Compact circuits required precise client-side cryptographic normalization before submitting secret parameters to the proof server.

Accomplishments I am Proud Of

• 100% green compilation across all Compact circuits (toggleAccepting, setRequiredBadgeHash, verifyAccess).
• Complete end-to-end ZK selective disclosure lifecycle working in real time.

What I Learned

How state-segregated public/private computation on Midnight Network enables "share proof, not data" paradigms impossible on transparent public blockchains.

What's Next for GhostBio

• Deploying to Midnight Testnet/Mainnet.
• Mobile pass integration (Apple & Google Wallet ZK passes).
• B2B SaaS onboarding for major Web3 conferences and hackathons.

Built With

• compact
• docker
• midnight-network
• node.js
• react
• typescript
• vite
• web3
• zero-knowledge-proofs
• zkir