Withdrawing

How to withdraw ETH privately from Shinobi Cash.

Overview

Withdrawing uses a zero-knowledge proof to verify you own a deposit without revealing which one. The recipient can be any address on any supported chain.

Withdrawal Steps

1. Navigate to Withdraw — Select the Withdraw tab
2. Select a Note — Choose a note with available balance
3. Enter Amount — Up to the note's full balance
4. Enter Recipient — Any valid Ethereum address
5. Select Destination Chain — Where funds should arrive
6. Review Fees — Relay fee + solver fee (if cross-chain)
7. Confirm — Proof generates in your browser, then submits

Proof Generation

When you confirm a withdrawal, your browser generates a Groth16 SNARK proof:

Generating proof... (~5-15 seconds)

This proof verifies:

• You know the secret for a valid commitment
• The commitment is in the state tree
• The commitment is in the ASP tree (compliant)
• The nullifier hasn't been spent

Keep the tab active — Proof generation uses your browser's compute resources.

No Wallet Gas Required

Shinobi Cash uses ERC-4337 Account Abstraction to relay withdrawals:

• You don't need ETH in your wallet for gas
• Transaction is relayed via standard ERC-4337 bundlers (no custom relayer)
• A paymaster sponsors the gas upfront
• Gas cost is deducted from your withdrawal amount (relay fee)

This means you can withdraw to a fresh address without needing to fund it with gas first.

Same-Chain Withdrawal

When withdrawing on the pool chain (Arbitrum Sepolia):

1. Proof validates in the pool contract
2. Funds transfer directly to recipient
3. Paymaster sponsors gas

Fees: Relay fee only (covers gas)

Cross-Chain Withdrawal

When withdrawing to another chain (e.g., Base Sepolia):

1. Proof validates on pool chain
2. Intent created with escrowed funds
3. Solver fills on destination chain
4. Recipient receives funds
5. Solver claims escrow after proving fill

Fees: Relay fee + 5% solver fee

What Happens Behind the Scenes

Your browser generates ZK proof
          │
          ▼
Entrypoint validates → Pool spends nullifier → InputSettler (escrow)
                                                      │
                                  Solver detects ◄────┘
                                         │
                                         ▼
                        WithdrawalOutputSettler → Recipient gets ETH
                                         │
                        Solver claims escrow

Change Notes

If you don't withdraw the full balance, a change note is created:

Original Note: 1.0 ETH
Withdrawal:    0.3 ETH
Change Note:   0.7 ETH (minus fees)

This mirrors how cash transactions work — you get change back.

Fee Structure

The relay fee is dynamic based on gas prices. Maximum 15%.

Withdrawal States

Tips

Troubleshooting

Proof generation is slow

• Keep the browser tab active and focused
• Close other resource-heavy tabs
• Normal time: 5-15 seconds

Transaction failed

• Check the note is still available (not spent elsewhere)
• Verify recipient address is valid
• Ensure ASP approval is complete

Cross-chain withdrawal stuck

• Solvers usually fill within minutes
• If expired, funds return as a refund commitment
• Refund can be withdrawn normally

What Can Go Wrong?

Next Steps

• Privacy Pools — Understand the cryptography
• Cross-Chain Architecture — How OIF works
• FAQ — Common questions