Privacy & Scalability with ZK Proofs

Identity requires privacy. Decentralization requires scalability. ZKID combines both using modern ZK cryptography.

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Why Zero-Knowledge Matters in Identity

Traditional verification leaks data.

Example: A centralized KYC platform checks your passport → stores your data → becomes a honeypot.

ZKID solves this with zero-knowledge proofs.

With ZKID, the user can prove:

• age

• uniqueness

• membership

• eligibility

• reputation score

• credential validity

without exposing:

• who they are

• where they live

• what wallet they use

• what their real identity is

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Core ZK Techniques Used in ZKID

ZKID is flexible and can support multiple ZK primitives:

✅ Groth16: Fast, efficient, widely supported.

✅ PlonK: Universal setup, reusability.

✅ Halo2: Recursive ZK proofs for advanced identity cases.

✅ Circom: Toolkit for building custom circuits.

All are compatible with the ZKID verification architecture.

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Example: Zero-Knowledge Age Verification Circuit

Here’s a minimal circuit showing ZKID’s logic:

template GreaterThan18() {
    signal private input birth_year;
    signal output result;

    result <== ((2025 - birth_year) >= 18);
}

This demonstrates:

• private inputs

• public verification

• no leakage

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Proof Verification Contract (Simplified)

Solana verifies proofs through:

• off-chain generation

• on-chain verification

• no state exposure

ZKID implements verification logic similar to:

pub fn verify_proof(ctx: Context<Verify>, proof: Vec<u8>, public_inputs: Vec<u8>) -> Result<()> {
    require!(zk_verify(proof, public_inputs), ZkError::InvalidProof);
    Ok(())
}

This contract:

• checks validity

• ensures consistency

• prevents invalid claims

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Privacy-Preserving Credential Verification

Using ZK proofs, ZKID enables:

✅ Proof of membership ✅ Proof of uniqueness ✅ Proof of age ✅ Proof of contribution ✅ Proof of DAO role ✅ Proof of compliance

Without revealing:

🚫 wallet addresses 🚫 personal data 🚫 full credential content 🚫 private keys

Zero-knowledge means zero unnecessary exposure.

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zkSync-inspired scalability

Even though ZKID lives on Solana, ZKID applies principles similar to zkSync:

✅ batching

DID updates and credential states can be batched

✅ proof aggregation

Solana verifies compact aggregated proofs

✅ per-epoch finalization

Validators finalize state updates per epoch and anchor them to Bitcoin.

This ensures:

• predictable costs

• high throughput

• strong privacy

• global consistency

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ZKID Validator Workflow

Validators:

1. verify state transitions

2. validate ZK proofs

3. sync compressed states

4. build Merkle roots

5. anchor epochs to Bitcoin

6. publish proof-of-validity snapshots

They secure:

• DID updates

• VC revocations

• metadata consistency

All without needing to see any personal data.