Zero-Knowledge Proofs · Range Proof

Prove the threshold.
Hide the number.

A Range Proof lets you show a hidden number clears a bar — “18 or older,” “over $1,000,000” — without ever revealing the number itself. Digital identity and financial audits run on the exact same mechanism underneath. Pick a use case below and generate a real proof flow with your own value.

Can a bar confirm you're 21+ without ever learning your birthdate?
Trusted authority: State DMV
Only your device ever reads this value.
This number is public — everyone knows the rule being checked.
Step 1 · Setup Waiting

Cryptographic Commitment

The trusted authority seals your true data into a tamper-proof "envelope" and signs it with their private key. This is issued once to your wallet.

Awaiting proof request…
Step 2 · Logic Waiting

Arithmetic Circuit

Your device opens the sealed envelope locally, runs the threshold check, and produces a proof — the real number never leaves your device.

Awaiting proof request…
Step 3 · Verification Waiting

Verification

The verifier runs one fast check on the proof against the authority's public key. No envelope, no real data — just a yes/no they can trust.

Awaiting proof request…
Stays on your device
proof only
What the verifier receives

1. The Commitment

You can't generate a proof out of thin air — the data has to be anchored to a trusted source first (a DMV, a bank). That authority seals your true data into a mathematically tamper-proof commitment and signs it with their private key.

2. The Circuit

An arithmetic circuit is just the question in math form — "is age ≥ 21?", "is balance ≥ $1,000,000?" It runs locally, on your device, against the sealed data. Nothing here is sent anywhere.

3. The Verification

The output is the proof itself: a guarantee the data was genuinely signed by the authority and the circuit evaluated to true. The verifier checks that proof against the authority's public key — fast, and without ever seeing the envelope.

This is a conceptual simulation for teaching purposes — the "commitment hashes" shown are illustrative, not cryptographically secure primitives. Real range-proof systems (e.g. Bulletproofs, zk-SNARKs) use elliptic-curve commitments and succinct circuits; the flow of trust — commit, compute locally, verify without revealing — is the same.