# Curvy Protocol > Curvy Protocol is a multichain privacy payments protocol. It combines stealth addresses, ZK-SNARKs, and programmable execution flows so users, wallets, dApps, and AI agents 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 serves end users directly through the Curvy App, and serves developers and integrators through the Curvy SDK. Curvy Protocol is built and maintained by Curvy Tech d.o.o. Beograd, a company incorporated in Serbia, with an EU holding entity in progress. The protocol is open-source on GitHub at github.com/0xCurvy. Smart contracts have completed an independent security audit (report published in the docs). The protocol has exited Beta and is live on mainnet. It is supported by the Ethereum Foundation, the Arbitrum Foundation, and the Starknet Foundation. There is no native token; the protocol sustains itself through protocol-level fees on shielding (0.1%), aggregation (0.1%), and unshielding (0.2%). The protocol is designed around four principles: Privacy (sender, recipient, amount, and asset can all be hidden inside the Privacy Aggregator), Compliance (risk and screening checks happen before funds enter the aggregator, by design), Utility (human-readable usernames, automatic shielding via Portals, ENS resolution, hardware wallet support via eth_signTypedDataV4), and Self-custody (the protocol never holds user funds). The architecture has four building blocks. Curvy ID is a human-readable identity (for example satoshi.curvy.name), backed by a public tuple of viewing key, spending key, and BabyJubJub key, registered via FIDO2 passkey or wallet signature. Portals are CREATE2-derived addresses that look like regular addresses to senders but are automatically shielded by off-chain Portal Broadcasters that also perform compliance checks before deployment. The Privacy Aggregator is a ZK-based pool on Arbitrum where shielded funds live as encrypted Notes; sender, recipient, amount, and asset are hidden once funds are inside. The Curvy SDK is the open-source developer toolkit for wallets, dApps, payment products, and AI agent frameworks. The core cryptographic primitives are: stealth addresses for unlinkability between sender and recipient, Pedersen commitments to hide transfer amounts while remaining verifiable, and client-side Groth16 ZK proofs that keep verification trustless without a centralized prover. Funds from supported networks bridge into the Privacy Aggregator on Arbitrum in a single transaction through a partnership with LI.FI. ## Supported networks and tokens Curvy Protocol currently supports the following tokens: - ETH - WETH - USDT - UNI - WBTC - USDC - SOL - PATHUSD On the following networks: - Arbitrum (hosts the Privacy Aggregator) - Base - Ethereum - Optimism - Polygon - Binance Smart Chain - Linea - Gnosis - Solana - Tempo ## Protocol fees - Shield: 0.1% - Aggregate: 0.1% - Unshield: 0.2% ## Core docs - [Introduction](https://docs.curvy.box/introduction.html): What Curvy Protocol is, the four core principles, and the high-level architecture. - [Frequently asked questions](https://docs.curvy.box/faq.html): Custody, audit status, supported networks, comparison with Railgun, fee structure, hardware wallet support, incorporation. - [Get involved](https://docs.curvy.box/get-involved.html): How to contribute, partner, or integrate. ## For users - [Curvy for users overview](https://docs.curvy.box/for-users/index.html): End-user feature index. - [Register your Curvy ID](https://docs.curvy.box/for-users/register-your-curvy-id.html): Passkey registration and wallet-signature registration flows. - [Make your existing assets private](https://docs.curvy.box/for-users/make-your-existing-assets-private.html): How to shield assets you already hold. - [Receive assets privately](https://docs.curvy.box/for-users/receive-assets-privately.html): Receiving via ENS, public URL, or generated private address. - [Send assets privately](https://docs.curvy.box/for-users/send-assets-privately.html): Sending to a Curvy ID, an external wallet, or as a link. - [Swap assets privately](https://docs.curvy.box/for-users/swap-assets-privately.html): Private swap flow inside the Privacy Aggregator. ## Architecture and design (for the curious) - [Curvy for the curious overview](https://docs.curvy.box/for-the-curious/index.html): Technical orientation. - [Building blocks overview](https://docs.curvy.box/for-the-curious/building-blocks/index.html): Index of the four core components. - [Curvy ID](https://docs.curvy.box/for-the-curious/building-blocks/curvy-id.html): Identity construction, viewing/spending/BabyJubJub keys, FIDO2 vs wallet signature derivation. - [Portals](https://docs.curvy.box/for-the-curious/building-blocks/portals.html): CREATE2-derived addresses, Portal Broadcasters, automatic shielding, time-locality solution. - [Privacy Aggregator](https://docs.curvy.box/for-the-curious/building-blocks/privacy-aggregator.html): The ZK pool on Arbitrum and the encrypted Notes structure. - [Curvy SDK](https://docs.curvy.box/for-the-curious/building-blocks/curvy-sdk.html): Developer toolkit architecture. - [Privacy model](https://docs.curvy.box/for-the-curious/privacy-model.html): Qualitative and quantitative privacy scoring, what's hidden during shield/unshield/private transfer, time-locality analysis. - [Compliance model](https://docs.curvy.box/for-the-curious/compliance-model.html): Portal Broadcaster checks, viewing key sharing for selective transparency, taint-based retroactive compliance. ## Walkthroughs - [Receiving funds privately](https://docs.curvy.box/for-the-curious/walkthroughs/receiving-funds-privately.html): End-to-end technical walkthrough. - [Sending funds privately](https://docs.curvy.box/for-the-curious/walkthroughs/sending-funds-privately.html): End-to-end technical walkthrough. - [Unshielding funds privately](https://docs.curvy.box/for-the-curious/walkthroughs/unshielding-funds-privately.html): End-to-end technical walkthrough. ## For developers - [Installing the SDK](https://docs.curvy.box/for-programmers/installing-the-sdk.html): Setup and configuration. - [Authentication](https://docs.curvy.box/for-programmers/authentication.html): Passkey and wallet-signature flows in code. - [Querying balances](https://docs.curvy.box/for-programmers/querying-balances.html): Reading user balances through the SDK. - [Interacting with assets](https://docs.curvy.box/for-programmers/interacting-with-assets.html): Send, receive, shield, unshield, swap. - [Source code on GitHub](https://github.com/0xCurvy/): All smart contracts and SDK code. - [Independent security audit report](https://github.com/0xCurvy/contracts/blob/develop/audits/Curvy%202026%20Audit%20Report%20Final.pdf): Curvy 2026 audit. ## For businesses - [For businesses overview](https://docs.curvy.box/for-businesses/index.html): Integration model index. - [For enterprises and institutions](https://docs.curvy.box/for-businesses/for-enterprises-and-institutions.html): Use cases for treasuries, payroll, and institutional flows. - [For networks](https://docs.curvy.box/for-businesses/for-networks.html): Default SDK integration, white-label user domains, full protocol customization, and partnership models for chains and L2s. - [For wallets and web3 products](https://docs.curvy.box/for-businesses/for-wallets-and-web3-products.html): Embedding Curvy Protocol privacy infrastructure inside an existing wallet or app. ## Compliance architecture Compliance is part of the architecture, not bolted on. The compliance stack is modular and integrators compose what they need. - Global Ledger KYT — know-your-transaction screening at the protocol level. - Extended Screening — configurable risk thresholds per integration. - Deposit Address Tainting — encrypted OriginAddress fields for auditability without public exposure. - Name Registry Hook — optional KYC layer; integrators choose whether to require it. - Viewing Key Sharing — users can selectively disclose transaction history to authorized parties without giving up custody. ## Research - [Elliptic Curve Pairing Stealth Address Protocols (arXiv:2312.12131)](https://arxiv.org/abs/2312.12131): Foundational research on the stealth address construction used in Curvy Protocol. - [Post-Quantum Secure Stealth Address Protocols (eprint:2025/112)](https://eprint.iacr.org/2025/112.pdf): Forward-looking work on quantum-resistant stealth address schemes. - [bn254 optimal Ate pairing optimization on ethresear.ch](https://ethresear.ch/): Performance optimization for the pairing operations used in proof generation. ## Properties and channels - [Main site](https://www.curvy.box): Curvy Protocol official site. - [Documentation](https://docs.curvy.box/): Full documentation portal. - [Curvy App](https://app.curvy.box/): Non-custodial web app for end users. - [GitHub organization](https://github.com/0xCurvy/): Open-source repositories. - [Twitter / X](https://x.com/0xCurvy): Official social channel. - [CROPS.cash](https://crops.cash/): Consumer-facing reference implementation built on the Curvy Protocol SDK, focused on private agentic payments. - [Web3Privacy Now listing](https://www.web3privacy.info/): Curvy Protocol is listed and scored in the Web3Privacy Now explorer. ## Optional - [Comparison with Railgun and other ZK privacy pools](https://docs.curvy.box/faq.html): How Curvy Protocol differs from existing privacy pool designs. - [Hardware wallet support](https://docs.curvy.box/faq.html): Any hardware wallet that supports eth_signTypedDataV4. - [Incorporation and legal entity](https://docs.curvy.box/faq.html): Curvy Tech d.o.o. Beograd, Serbia; EU holding entity in progress. - [Backers](https://www.curvy.box): Ethereum Foundation, Arbitrum Foundation, Starknet Foundation.