zk.money Returns After Three Years with Private Payments on Ethereum

zk.money is back, with private payments and a friendlier way to find recipients. But the relaunch is still a cautious experiment. Each deposit, payment and withdrawal must stay below $2,500, and users share a replenishing $50,000 daily deposit allowance.

The wallet runs on Aztec Network, Aztec Labs' privacy-focused Ethereum Layer 2. Unlike a standard Ethereum wallet, it does not publish users' balances, payment amounts or counterparties on a public ledger, according to Aztec.

That difference matters if you don't want every payment attached to a public address. It doesn't make the payment invisible at its entry point, though. A deposit from Ethereum still reveals the sender and amount. The recipient can remain private after the funds enter Aztec.

A shorter name, then a link

The most useful change may also be the least technical. Instead of copying a long Ethereum address, a user can claim a handle such as bob.zk.money. Payments can be sent or requested through a link, and users can decide who may interact with their handles.

The handles use Ethereum Name Service technology, which means they can work with other apps that support ENS. Funds can also move from Ethereum-based exchanges directly to a zk.money handle.

It's a small concession to a plain question: how do you pay someone without making them check every character? Aztez Labs has spent much of its effort on the harder question beneath it, which is how an Ethereum transaction can avoid exposing the recipient's balance and payment history.

Self-custody has a server in the room

zk.money is non-custodial, meaning Aztec Labs says it cannot spend, move or freeze users' funds. Access is available through the web, and users can run the wallet locally. A mobile app is planned for Q4, but Aztec hasn't set a launch date.

The current design still includes a sealed server that co-signs operations inside zk.money. According to documentation, that server cannot spend a user's funds on its own.

There are fewer currencies inside the wallet, too. Users can deposit DAI, USDC or USDT from Ethereum, but USDC and USDT are converted into DAI. That leaves DAI as zk.money's only currency for now, though Aztec Labs says more assets could be supported later.

Andrews said the company chose DAI because it considers it the most decentralized of the mass-market stablecoins used on Ethereum. That's the company's judgment, not a claim that DAI removes every risk associated with the asset.

Privacy starts after the deposit

Aztec's privacy begins with the activity inside its own network, not the moment funds leave Ethereum. An Ethereum deposit remains publicly traceable and shows the sender and amount. Once the recipient enters zk.money, their identity, balance and counterparties need not appear on the public ledger.

That boundary is simple enough to picture. Moving money into zk.money is like entering a bank through a public street. Activity after that happens behind a screen, though the deposit at the doorway remains visible.

The limits tell you how Aztec is approaching the launch. Every deposit, payment and withdrawal must be below $2,500. All users share a $50,000 daily deposit allowance that replenishes over time, and the documentation says raising the caps would require a new contract.

Andrews said the limits reflect a system built on new, experimental cryptography. Aztec Labs plans to raise them as confidence grows, but that work hasn't happened yet.

A deposit costs 35 cents plus Ethereum fees. Withdrawals cost 20 cents, and each user receives 100 sponsored transactions per day inside zk.money. Ethereum-based exchanges screen addresses used for deposits and withdrawals against a sanctions policy.

A critical flaw remains unresolved

The relaunch also comes with a significant warning. Aztec's documentation says its software hasn't been fully audited and that critical bugs remain possible. Contributors disclosed a critical flaw in the V5 proof system in August, with a fix planned for V6.

Andrews said zk.money would launch before that flaw was fixed. A separate system called Oxide is intended to check payments for errors caused by bugs in the network's software. But that isn't the same as completing the fix, and the flaw hadn't been resolved at launch.

The risk doesn't appear confined to the older zk.money product. Aztec said two older smart contracts exploited in June belonged to products shut down years earlier. They weren't part of the current network, and the company said zk.money wasn't affected. The V5 issue is separate and remains unresolved.

From a shut-down wallet to a network product

The original zk.money launched in 2021 and was discontinued in 2023 as Aztec Labs redirected its work toward building Aztec Network. The sources disagree on whether the product closed in 2023 or 2024, so the broad point is clearer than the precise date: Aztec Labs stopped the first wallet, then returned to the product after building new infrastructure.

Aztec says the first version reached more than 75,000 unique wallets and processed more than $100 million in volume. Those figures belong to the earlier product, and there is no independent adoption or volume data yet for the relaunch.

The company is also planning to connect zk.money with Ethereum DeFi protocols. Integrations are expected in Q4, though Aztec hasn't named potential partners. Ethereum developers are separately considering changes in the planned 2027 Hegotá upgrade that could give privacy apps more control over transaction approvals and fees. Those proposals haven't been adopted.

zk.money now offers a clearer path to private payments within Aztec, along with handles, links and lower-friction transfers. The product has returned with its privacy boundary drawn clearly: the Ethereum deposit is public, activity inside zk.money isn't. Its small transaction caps, shared deposit allowance and unresolved proof-system flaw show that this is a launch to approach carefully, not a finished answer.