# Zero-Knowledge Proofs

> ZK circuits, zk-SNARKs, and privacy-preserving transactions.

- Skill: `j4flmao/zero-knowledge-proofs` (Agent Skill)
- Install (CLI): `npx skillmds@latest add j4flmao/zero-knowledge-proofs`
- Raw SKILL.md: https://api.skillmd.com/api/skills/j4flmao/zero-knowledge-proofs/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: j4flmao (https://skillmd.com/u/j4flmao)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/j4flmao/zero-knowledge-proofs

---


# Zero-Knowledge Proofs

## ZK Circuits (Circom)
Create arithmetic circuits to prove knowledge of a pre-image without revealing it.

```circom
pragma circom 2.0.0;
include "node_modules/circomlib/circuits/poseidon.circom";

template SecretHasher() {
    signal input secret;
    signal output hash;

    component poseidon = Poseidon(1);
    poseidon.inputs[0] <== secret;
    hash <== poseidon.out;
}

component main = SecretHasher();
```

## zk-SNARKs
Use Groth16 or Plonk for succinct non-interactive arguments of knowledge. Ensure trusted setup (PTAU) for Groth16.

## Privacy Protocol Architecture
```mermaid
%%{init: {"theme": "default", "flowchart": {"useMaxWidth": true}}}%%
graph TD
    User[User] -->|Secret| Circuit[ZK Circuit]
    Circuit -->|Proof| Prover[Prover Node]
    Prover -->|Submit Proof| Contract[Verifier Smart Contract]
    Contract -->|Valid?| State[Update State]
```