ZK-Rollup Simulator (PoC V1)

A proof-of-concept simulation of ZK-Rollup architecture. The system handles the basic transaction flow — deposit, internal transfer, and withdrawal — using a Sparse Merkle Tree, EdDSA signatures, and PLONK proofs via Circom/SnarkJS.

Documentation

• System Design V1 — data flow, security invariants, API reference
• ZK Circuit Spec — Circom constraints breakdown
• Proving Environment — Circom/SnarkJS setup and proof generation scripts

---

Architecture

Four components communicating over HTTP/JSON:

Component	Port	Role
L1 Server	3000	Smart contract simulation (Vault, ZK verifier, deposit queue) + L1 Explorer UI
L2 Server	5000	Sequencer (mempool, state, batch relay) + L2 Web Wallet UI
Archive Node	4000	Stores DA blobs; provides transaction data for withdrawal Merkle proofs

Treasury model: L2 has a special Treasury account (balance = MAX_UINT128). Every deposit is Treasury → User; every withdrawal is User → Treasury. No minting — total supply is constant.

---

Known Limitations (V1)

1. batch_history stored on-chain — grows without bound. On real EVM, each batch write costs ~20,000 gas/slot.
2. pending_deposits stored on-chain — same issue; production systems use event logs instead.
3. JSON ≠ EVM slot model — the 256-bit slot storage layout is not faithfully simulated.

V2 Roadmap

• Replace batch_history with a rolling hash (historical Merkle proof for withdrawals)
• Replace pending_deposits with an accumulator hash + EVM event logs
• Accurate EVM 256-bit slot storage simulation