Curvy Protocol: Multichain Privacy Payments for Public Blockchains
Curvy Protocol is a multichain privacy payments protocol. It combines stealth addresses, ZK-SNARKs, and programmable execution flows so users, wallets, and dApps can send and receive crypto privately on the chains they already use. Curvy Protocol is non-custodial, open-source, and live on mainnet.
The protocol is built around three audiences:
- Users who want private sends and receives with a username instead of a 0x address
- Developers who want to add private payments through the Curvy SDK[/color]
- Networks, wallets, and enterprises who want privacy infrastructure they can integrate or white-label
Smart contracts are open-source on GitHub and have
completed an independent security audit.
What Curvy Protocol Is, Specifically
Curvy Protocol is often described as "a stealth address protocol." That is incomplete. Curvy Protocol builds on the stealth address approach and extends it with a ZK aggregator and programmable transaction routing, so private receiving and private execution work together as one system.
Four principles guide the design:
- Privacy — sender, recipient, amount, and asset can all be hidden inside the Privacy Aggregator
- Compliance — risk and compliance checks happen before funds enter the aggregator, by design
- Utility — usernames, automatic shielding, hardware wallet support, ENS resolution
- Self-custody — Curvy Protocol never holds user funds
The Building Blocks
Curvy IDA human-readable identity like
satoshi.curvy.name, backed by a public tuple of viewing key, spending key, and BabyJubJub key. Users register with a FIDO2 passkey or a signature from an existing wallet. ENS resolution is supported. A user can share their viewing private key with a third party such as an auditor or accountant to grant read-only access to their transaction history, without giving up custody.
PortalsThe cornerstone of Curvy Protocol's UX and the answer to the time-locality problem that breaks most privacy tools. A Portal is a deterministically derived address (CREATE2-style) generated from a Curvy ID. To senders, it looks like a regular address they can pay normally. Off-chain workers called Portal Broadcasters scan announcements, deploy the Portal when funds arrive, run compliance checks, and automatically shield the funds into the Privacy Aggregator. The recipient never has to interact with the shielding step.
Privacy AggregatorA ZK-based pool where shielded funds live as encrypted Notes. Sender, recipient, amount, and asset are hidden once funds are inside. To avoid liquidity fragmentation and minimize gas costs, the Privacy Aggregator lives on Arbitrum. Funds shielded from other networks bridge to Arbitrum automatically through Curvy Protocol's partnership with LI.FI.
Curvy SDKOpen-source developer toolkit. Install, authenticate, query balances, send and receive private transactions. The SDK is the primary integration surface for wallets, dApps, and payment products.
Supported Networks
Curvy Protocol is multichain and native to the chains the world uses.
Full Curvy Protocol support (stealth addresses + Privacy Aggregator):
- Solana
- Tempo
- Ethereum
- Arbitrum (hosts the Privacy Aggregator)
- Base
- Optimism
- Polygon
- BNB Smart Chain
- Linea
- Gnosis
Network coverage continues to grow. For the current status of each integration, the docs are the source of truth.
Privacy Model
Curvy Protocol's privacy guarantees vary by transaction type. The docs cover this in detail. Summary:
- Shielding funds in — sender, amount, and asset are public; recipient is hidden
- Unshielding funds out — recipient, amount, and asset are public; sender is hidden
- Private transfers inside the aggregator — sender, recipient, amount, and asset are all hidden
One honest point worth surfacing. Curvy Protocol solves address linkability, the question of who paid whom. Timing and volume correlation, the question shielded pools address, is a separate and complementary problem. The Portal architecture mitigates time-locality attacks by automatically shielding funds at the receive time, so the recipient never has to make a high-signal deposit-then-withdraw move.
Compliance Model
Compliance is part of the architecture, not an add-on.
- Portal Broadcasters perform risk and compliance checks before deploying a Portal and shielding funds. Non-compliant funds can be recovered to a stealth recovery address instead of being admitted into the aggregator.
- Selective transparency is opt-in. A user can share their viewing private key with an auditor or compliance entity to grant read-only access to their history.
- Retroactive compliance frameworks including taint-based models are in active development where legally required.
Privacy and compliance are parallel features in Curvy Protocol. Not opposites.
How Curvy Protocol Compares
Curvy Protocol is often compared to Railgun and other ZK privacy pools. The differences:
- Stealth addresses for the best UX when receiving funds privately
- Human-readable usernames via Curvy ID
- Portals that automatically shield received funds, defeating time-locality leaks without user intervention
- Programmable transaction routing and flow automation
- Compliance hooks integrated at the protocol layer
- Multichain coverage across EVM networks, Starknet, and expanding to Solana and Tempo
For Developers
The SDK is the primary surface. Documentation at
docs.curvy.box/for-programmers covers installation, authentication, querying balances, and interacting with assets.
Smart contracts are open-source at
github.com/0xCurvy and verified on block explorers.
For Networks, Wallets, and Enterprises
Curvy Protocol supports several integration models:
- Default SDK integration — out-of-the-box private send/receive and stealth address support
- White-label user domains — your namespace (e.g., satoshi.yourdomain.io) instead of satoshi.curvy.name
- Full protocol customization — transaction routing, integrated DeFi protocols, supported tokens, fee config, subsidized privacy flows, adoption incentives
- Wallet integration — privacy infrastructure embedded directly into wallets
Details for networks:
docs.curvy.box/for-businesses/for-networks.
Quick FAQ
Is Curvy Protocol a wallet?No. Curvy Protocol is a privacy payments protocol. The Curvy App is a non-custodial reference web app built on the protocol.
Does Curvy Protocol have custody of my assets?No. Self-custody is preserved at every step.
Is it audited?Yes. The independent security audit is complete and the report is published in the docs.
Hardware wallets?Yes. Any hardware wallet that supports
eth_signTypedDataV4 works.
Where is the company incorporated?Curvy Tech d.o.o. in Belgrade, Serbia. A holding entity in the European Union is being established.
How does Curvy Protocol sustain itself?Through protocol-level fees: 0.1% on shielding into the Privacy Aggregator, 0.1% on aggregation, 0.2% on unshielding.
Can Curvy Protocol trace my transactions?No. By design, no single party can reconstruct user transaction history. Users may voluntarily share a viewing key to grant selective read-only access.
Reference Implementation: CROPS.cash
CROPS.cash is a consumer-facing product built on the Curvy Protocol SDK, focused on private AI agentic payments. It is a working reference for what teams can build on top of the protocol.
Research
Curvy Protocol's cryptographic work is published openly:
Ecosystem Support
- Ethereum Foundation
- Starknet Foundation
- LI.FI partnership for bridging
- MVP Workshop and 3327.io
- EthCC speaker history
- MoneyMotion 2026 Zagreb startup pitch finalists
Get in Touch
Docs: docs.curvy.box
Try the app: app.curvy.box
GitHub: github.com/0xCurvy
Twitter: @0xCurvy
