ZKP2P

ZKP2P is a trust-minimized, non-custodial peer-to-peer marketplace for converting between fiat and crypto. Originally launched under the ZKP2P name in late 2023, the project has since rebranded to Peer and operates at peer.xyz, while the underlying open protocol retains the ZKP2P name. Operated by P2P Labs Inc, it removes the central intermediary from the fiat-to-crypto conversion step by letting buyers pay sellers directly through their existing payment apps — Venmo, PayPal, Cash App, Revolut, Wise, Zelle, Monzo, and others — and then using cryptographic proofs to confirm those payments on-chain without a custodian ever holding both sides of the trade.

How It Works

The core mechanic is a two-sided escrow-plus-attestation loop. Sellers deposit USDC into smart contracts on-chain, setting their own exchange rate and terms. When a buyer selects an order, the contract locks the seller's liquidity. The buyer then pays the seller directly in fiat through their chosen payment app. The protocol next verifies that the payment occurred — confirming amount, timestamp, currency, and payment ID — using a cryptographic attestation. Once the contract validates the attestation against the buyer's declared intent, it releases the escrowed tokens to the buyer. At no point does Peer hold, control, or transmit user funds; the smart contracts enforce settlement automatically.

The attestation layer has evolved through three protocol versions. V1 relied on zkEmail: ZK proofs of DKIM signatures embedded in payment confirmation emails, generated using circom and halo2 circuits. V2 introduced a browser extension called PeerAuth and expanded to proxy-TLS and TLSNotary (MPC-TLS) approaches. V3, the current production version, migrated attestation to AWS Nitro Enclaves — Trusted Execution Environments that validate payment evidence and return an EIP-712 PaymentAttestation signed by KMS keys gated to the enclave's code measurement. This shift from ZK circuits to TEE-based attestation trades the purely cryptographic trust model of V1 for speed and broader payment method coverage.

Products and Features

Peer is the consumer-facing application (app.peer.xyz), providing a mobile and web interface for individuals to buy and sell crypto. Sellers set their own rates and can earn a spread above market price; buyers get access to rates that often undercut centralized ramp providers, which typically charge 3.5–4.5%. The published taker service fee is up to 0.95%, with an optional 0.5% bridge fee for cross-chain delivery.

ZKP2P is simultaneously an open, permissionless protocol that other developers can build on top of. The project provides a client SDK and APIs for integrating on/offramp functionality into third-party applications, documented at docs.peer.xyz.

No KYC is required for initial transactions. Privacy is built into the attestation design: only the payment amount, recipient, timestamp, and transaction ID are disclosed to the smart contract.

Supported Payment Methods and Chains

On the fiat side, the protocol currently supports Venmo, Cash App, Zelle, PayPal, and Wise for USD flows; Revolut and Wise for EUR flows; Monzo for GBP; and HDFC Bank for INR flows.

On the crypto side, the protocol supports delivery to Base (where V3 smart contracts are primarily deployed), Ethereum, Polygon, Solana, Hyperliquid, and more than twenty additional chains. Tokens supported include USDC, ETH, and SOL, with USDC being the primary liquidity asset in escrow.

Security and Audit Status

V3 uses AWS Nitro Enclaves as the attestation environment, with signing keys managed by AWS KMS and gated to a specific enclave code measurement — meaning any modification to the enclave binary invalidates the signing key. The smart contracts have a simplified on-chain surface in V3 compared to earlier versions. The Alpha launch was described as a productionized version with audits completed; specific audit firm names and reports are not linked from public documentation.

Team and Background

ZKP2P originated as a research project supported by the Ethereum Foundation's Privacy and Scaling Explorations (PSE) program. The project was founded in November 2023 and iterated rapidly through three protocol versions in under two years. The @zkp2p X account migrated to @peerxyz alongside the rebrand.

Fit Within the Solana Ecosystem

Solana is one of the destination chains supported by the ZKP2P protocol, enabling users to receive SOL or Solana-based USDC directly from a fiat-to-crypto trade without going through a centralized exchange. The protocol's non-custodial design and low fee structure complement Solana's high-throughput, low-fee architecture: users can enter the Solana ecosystem from Venmo or Revolut at a fraction of the cost charged by traditional ramp providers, with settlement driven by on-chain smart contracts rather than a company's risk assessment.