What Is Privacy Cash?
Most blockchains are radically transparent: if someone scans your wallet address on an explorer, they can see your balances and all transaction history. This can be uncomfortable and can pose security risks to the owner of the wallet being monitored. Privacy Cash exists to solve this problem.
With Privacy Cash, a user can send and receive funds with greater privacy than a standard on-chain transfer. Instead of sending assets directly from your wallet to someone else’s wallet (which permanently links sender and recipient on-chain), Privacy Cash helps you break that direct link so that no observer can connect who sends funds, who receives them, and how those addresses relate to your other on-chain activities.
Who is Privacy Cash for?
Privacy Cash can be useful if you don’t want to reveal your total wallet balance to a counterparty, or you want to pay someone without showing them your entire on-chain actions. Privacy Cash is also useful if you are trying to avoid address-based doxxing or targeted scams such as address poisoning.
How it works
Privacy Cash relies on cryptography (zero-knowledge proof) to let you prove something like “I deposited an eligible amount earlier, and I’m entitled to withdraw now” without revealing which deposit was yours. When you make deposits, they are recorded into a shared pool, but your account can access the amount it deposited because of the private secret it owns, which was generated during the zero-knowledge proof generation. This process occurred below when USDC tokens were swapped for SOL.
Using Privacy Cash
Connect your Solana wallet using one of the available options. After connecting a wallet, click “+ Top Up” to deposit from the token balance in your wallet. From this deposit, Privacy Cash facilitates all transfers, swaps and bridges privately. In the example below, I deposited some USDC. It is from this deposit that I can make private transactions that will be untraceable to my wallet.
Send Privately
To transfer a token privately, select “Send Privately” and input the amount to be transferred from the original deposit made in the “+ Top Up” section above. Enter the recipient address (this can be your fresh wallet, which you don't want traced back to you) and click “Send”. Privacy Cash generates its cryptographic proof underneath to obscure the sending wallet.
Swap
Apart from token transfers, Privacy Cash can be used to exchange tokens with privacy. For users who want to purchase a token without exposing their swaps on-chain, this feature makes it possible. After swapping, the token can be transferred to the “fresh wallet.” Please note that a recipient wallet can also be the sending wallet for users who only want the swap to be anonymous.
Bridge
Bridging is the process of transferring assets from one blockchain to another. This can be the same token (usually stablecoins), such as USDC from Solana to USDC on Ethereum or different tokens that are exchanged using cross-chain interoperability protocols, such as SOL on Solana to USDT on Ethereum.
What Privacy Cash does not protect you from
The advantage of Privacy Cash can be undermined by user behaviour, such as:
- Address Re-use: when one withdraws to a wallet address already linked to the sending wallet. Wallets that the sender has used to interact with the sending wallet in the past, should not be used to receive the same amount from the private pool.
- Timing: depositing and withdrawing immediately can be linked if the pool is small. A wallet watcher can detect a user’s private wallet if they immediately withdraw funds from the originating address.
- CEX Usage: sending withdrawn funds straight to a KYC exchange or to a known address can re-link activity.
Conclusion
Privacy Cash is solving a real and common problem in crypto. Public wallet activities expose personal transactions and reveal what a user may not want others to see. Privacy Cash enables Solana users to make transactions without worrying about their privacy anymore.
