How Ghostmode works

Overview

Ghostmode is an interface to Privacy Cash, an audited zero-knowledge privacy pool on Solana. Everyone's shielded funds sit in one shared pool. When you send, a proof shows you own some funds in the pool without revealing which ones, so the payment can't be traced back to your deposit.

Ghostmode is non-custodial. Your wallet signs deposits, your browser builds proofs, and nothing we run can move your funds.

Your private account

The first time you open the vault, your wallet signs the message Privacy Money account sign in. It isn't a transaction and costs nothing. The signature derives two things: the key that encrypts your notes and the key that spends them.

Ghostmode keeps that signature in memory only. Reload the page and you'll sign once more. Hardware wallets aren't supported, and switching accounts mid-signature derives the wrong key.

Shielding

Choose SOL, USDC or USDT and an amount. Your wallet signs one deposit transaction that moves funds into the pool and records an encrypted note only you can open. The relayer may take a few seconds to index it before it shows in your private balance.

The relayer may decline deposits from wallets flagged by its screening.

Private sends

Enter an amount and any Solana address. Your browser downloads the circuit (about 20 MB, cached after the first time) and generates a Groth16 proof, which takes from a few seconds to a minute depending on your device. A relayer submits the transaction and pays its network fee, so your wallet never appears in the send.

Each send spends at most your two largest notes. If they can't cover the amount, the send goes out partially and you can send again for the rest.

Fees & limits

• Shield: no protocol fee, just the Solana network fee.
• Send: a relayer fee of a small percentage plus a fixed rent amount, set live by the relayer and deducted from what you send. The send form shows the exact quote.
• Minimums and caps: each token has a minimum send, and the pool may cap deposit sizes. The app tells you if you hit either.

How private is it?

The chain sees that someone deposited and that the pool paid someone. It can't see which deposit funded which payment. Your privacy depends on blending in:

• Unusual exact amounts in and out are easy to match.
• Sending seconds after shielding narrows the crowd to almost nobody.
• Sending back to your own known wallet undoes the whole point.

Recovery

Your notes live on-chain, encrypted to a key derived from your wallet's signature. If Ghostmode disappears, any other Privacy Cash interface that uses the same sign-in message, including privacycash.org, can open the same balance from the same wallet.

Risks

This is experimental cryptography and software. The protocol is audited, but audits don't guarantee safety. Only shield what you can afford to lose, and follow the laws where you live.