Proving Age Over 10 with Zero Knowledge Proofs (Groth16 + gnark)

This project is a minimal and clean example showing how Zero Knowledge Proofs can be used to prove statements like "I am over 10 years old" without revealing your actual age.

🛠️ We use

• Groth16 zkSNARK proving system
• gnark — a modern zk framework in Go
• BN254 elliptic curve (BLS12-381 and others are also supported)
• Go as the programming language

🎯 What This Code Does

The code defines a cryptographic circuit that:

• Takes an input Age (private / secret input).
• Proves that Age > 10 without leaking Age.
• Uses binary decomposition to enforce non-negativity (Age - 11 >= 0). Uses the efficient Groth16 proving system to generate and verify the proof.

✅ Proof guarantees

• Completeness: If the prover knows an Age > 10, they can generate a valid proof.
• Soundness: If the prover does not have Age > 10, they cannot create a valid proof.
• Zero Knowledge: The verifier learns nothing about the actual Age.

📦 How to Run

Clone the repository.

git clone https://github.com/ananthanir/hello-zkp.git

Run the code.

cd hello-zkp
go run .

🛡️ About Groth16 and Trusted Setup

• Groth16 is a popular zkSNARK proving system with extremely small proof sizes (~200 bytes) and fast verification.
• Trusted Setup: Groth16 requires a one-time setup for each circuit to generate proving and verification keys. If the setup is compromised, the security guarantees are broken.
• In practice, trusted setups are generated through multi-party ceremonies to ensure security.