Relaunch Overview and Core Architecture
Aztec Labs has reintroduced its zk.money payment application to provide privacy-focused transfers on Ethereum 12. The application operates on the Aztec Network, an Ethereum Layer 2 scaling protocol that isolates user balances, transfer values, and counterparty identities from public viewing 12. To execute private transfers, user devices generate zero-knowledge proofs locally to confirm valid transactions without publishing sensitive data 2. Addresses on Ethereum remain transparent, meaning standard transfers display complete financial histories 1.
The relaunched interface allows individuals to request funds via shareable web links or target human-readable identity tags, such as bob.zk.money, which resolve through the Ethereum Name Service 12. Aztec Labs Chief Executive Officer Joe Andrews stated that onchain transactions between two individuals should not mean publishing financial histories to the world 12. The protocol is built as a self-custodial architecture, preventing operators or central entities from freezing or redirecting user balances 12.
Operating Mechanics, Stablecoins, and Cost Structure
Users can transfer stablecoins into the system using DAI, USDC, or USDT from Ethereum wallets or exchange accounts 12. When deposits arrive in USDC or USDT, the software converts those funds into DAI, making DAI the single internal asset within zk.money 1. Andrews explained that Aztec Labs chose DAI because it considers it the most decentralized of the mass-market stablecoins used today on Ethereum 1.
Internal transfers require no gas payments for up to 100 sponsored daily transactions per user, provided the supporting fee contract retains sufficient funding 1. External interaction costs include a 35-cent deposit fee alongside standard Ethereum execution costs, while withdrawals incur a 20-cent fee 1. Base layer deposits do not mask all metadata, as public Ethereum transactions still reveal the sender address and deposited value, even though the recipient identity within Aztec remains shielded 12. Future asset integrations may occur at a later stage according to project leadership 1.
System Limits, Security Controls, and Known Vulnerabilities
To manage risks associated with experimental cryptographic systems, strict transaction caps have been established across the platform 12. Individual deposits, internal transfers, and withdrawals are capped at $2,500 per transaction 12. All platform participants share a cumulative daily deposit threshold of $50,000, which recharges gradually over time 12. Modifying these transactional constraints would require deploying a new smart contract 1. Andrews noted that the limits are in place because the system uses new, experimental cryptography, adding that Aztec Labs plans to raise them as confidence grows 1.
Compliance measures include screening Ethereum addresses against a sanctions policy prior to deposit or withdrawal processing 1. Transaction co-signing inside zk.money is handled by a sealed server, which documentation confirms cannot unilaterally spend user balances 1. Software documentation explicitly warns that the codebase has not undergone a complete audit, creating potential exposure to critical bugs 1. In August, contributors disclosed a critical flaw in the V5 proof system, with a resolution planned for version V6 1. The current relaunch proceeds before the V5 fix is deployed, relying on an auxiliary system named Oxide to detect network-level payment errors until users can migrate to the updated architecture 1.
Historical Context and Surrounding Protocol Ecosystem
The original iteration of zk.money debuted in 2021 before operations were halted 12. Sources provide conflicting accounts regarding the closure timeframe, with one report stating the original platform operated until 2024 1, while another indicates the relaunch occurs three years after the service was discontinued 2. During its initial operation, the platform registered over 75,000 distinct wallets and processed more than $100 million in transaction volume 12. In 2021, Aztec raised $17 million in a funding round led by Paradigm 2. The developers subsequently expanded privacy features through Aztec Connect before sunsetting that product to focus on building a dedicated network 12.
The relaunch coincides with broader privacy discussions across Ethereum 12. Developers are weighing changes for the planned 2027 Hegotá upgrade—scheduled for next year—that would allow privacy applications and pools to handle transaction approvals and fees with less reliance on external services 12. The upgrade incorporates 66 proposals, including measures to enhance transaction privacy 1. Additionally, Ethereum co-founder Vitalik Buterin stated in a post that special-purpose applications could achieve very strong privacy using zero-knowledge proofs 2.
What is not yet established
- The exact timeline for raising transaction caps and deploying an updated contract.
- The specific safeguards applied to the relaunched wallet regarding the V5 proof system flaw beyond the Oxide error-checking system.
- When additional stablecoins or crypto assets will be directly supported inside zk.money beyond DAI.
Frequently asked questions
How does zk.money handle asset deposits and conversions?
Users can deposit DAI, USDC, or USDT from Ethereum, but USDC and USDT are automatically converted into DAI upon deposit, making DAI the sole internal balance currency 1.
What privacy limitations exist when transferring funds into zk.money?
While transfers inside zk.money mask sender, recipient, and amount details, depositing funds from Ethereum reveals the sender's public address and the deposit amount 12.
What fees apply to transactions within the zk.money application?
Depositing costs 35 cents plus Ethereum fees, withdrawals cost 20 cents, and users receive up to 100 free sponsored internal transactions daily 1.
Sources
- CoinDesk — Ethereum users get another way to pay privately as zk.money returns after three years (2026-09-29) https://www.coindesk.com/tech/2026/09/29/embargo-12-et-ethereum-users-get-another-way-to-pay-privately-as-zk-money-returns-after-three-years
- Decrypt — Ethereum Gets Another Privacy Boost as Aztec Brings Back zk.money (2026-09-29) https://decrypt.co/379621/ethereum-privacy-aztec-brings-back-zk-money
This brief is for information and education. It is not financial advice or a recommendation to buy or sell.