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cash out

unlocking instant liquidity for freelancers & SMEs using zk powered by vLayer

cash out

Created At

ETHGlobal Prague

Winner of

Rootstock - Everyday DeFi 2nd place

Project Description

Cash Out is a decentralized invoice financing and liquidity unlocking platform built for freelancers and SMEs. It addresses the global issue of delayed B2B invoice payments—over $3 trillion locked and 50,000+ business failures annually. The platform enables instant payments upon invoice confirmation using zero-knowledge proofs (ZKPs) powered by vLayer, with all transactions executed securely and privately on the Rootstock testnet.


🔍 Real-World Problem

  • 📉 61% of B2B invoices are paid late.
  • 🧾 SMEs lack legal and financial resources to enforce timely payments.
  • 🔒 On-chain financial transparency is avoided due to privacy concerns.
  • ❌ Cash flow gaps cause 50,000+ business failures each year in the US.

🚀 The Cash Out Solution

Cash Out provides a private, verifiable, and trustless mechanism for invoice financing.

  • ✅ Instant liquidity for suppliers via zk-proofs of invoice confirmation and buyer solvency.
  • 🔐 Privacy-preserving financial verification (e.g., Binance/Bybit proof, cross-chain averages).
  • ⛓️ Entire lifecycle is on-chain: transparent, tamper-proof, and automated.
  • 📊 Uses Pyth for reliable price feeds and Rootstock Attestation Service (RAS) for claim validation.

How it's Made

🔨 Technologies Used

| Component | Technology | |------------------------|------------------------------------------------| | Blockchain Base | Rootstock Testnet | | Privacy Layer | vLayer (ZK generation & verification) | | Proof Attestation | Rootstock Attestation Service (RAS) | | Oracle | Pyth Network (price conversion) | | Cross-Chain Proofs | Time Travel & Teleport (ZK multi-chain proofs) | | Asset History Proofs | Binance & Bybit portfolios (zk-verified) | | Token Payout | $RIF and $USDC |


🧠 Product Workflow

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👥 User Profiles

  • Clients and Suppliers register on-chain via a CreateProfile transaction.

🧾 Invoice Lifecycle

  1. Business issues an invoice and sends a confirmation email.
  2. Supplier parses the email and generates a zk-proof of the contents.

💰 Financial Solvency Verification

  • ZK-proofs of liquidity from:
    • Binance/Bybit exchange history
    • Cross-chain wallet balance (via Teleport + Time Travel ZK modules)

✅ Claim Verification

  • Supplier submits zk-proof to claim payment.
  • Creates an attestation on the Rootstock Attestation Service (RAS).

🪙 Payout

  • Funds released instantly in $RIF or $USDC to supplier’s wallet.

🤹 Hacky/Innovative Aspects

  • ✉️ ZK Email Proofing: Parses Gmail content and turns it into verifiable cryptographic claims.
  • 🌐 Cross-chain ZK Liquidity Proofs: Aggregates multi-chain balances without revealing wallet info.
  • 🧠 Proof-of-liquidity without trust: No credit scores, no raw data exposure—just pure cryptographic solvency.

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