Fusion Plus Bridge

Problem Statement

Fusion+ Bridge revolutionizes cross-chain DeFi by implementing trustless atomic swaps across Ethereum, Etherlink, and Stellar networks. Unlike traditional bridges that introduce custody and security risks, our solution uses cryptographic hashlocks and timelocks to ensure either all parties receive their funds or no exchange occurs.KEY INNOVATIONS:First implementation of 1inch Fusion+ atomic swaps on EtherlinkThree-chain liquidity aggregation using Stellar Soroban contractsAutonomous TEE-based solver using NEAR Shade Agent FrameworkDutch auction pricing mechanism ensuring competitive ratesChain Signatures enabling decentralized multi-chain controlTECHNICAL ARCHITECTURE:Smart Contracts: Solidity (Ethereum/Etherlink) + Rust (Stellar/NEAR)Frontend: React with seamless Web3 integrationAutomation: TEE worker agents on Phala CloudSecurity: Cryptographic atomic swaps with no bridge riskMARKET IMPACT:Addresses $200B+ cross-chain trading volumeEliminates bridge hacks and MEV extractionProvides 24/7 automated executionScales to support any blockchain networkThe project demonstrates advanced integration with all three sponsor technologies: Etherlink's EVM compatibility for seamless deployment, Stellar's Soroban platform for multi-chain liquidity, and NEAR's Shade Agents for autonomous execution. Each integration is meaningful and showcases the unique capabilities of the respective platforms.Target Prize Pool: $30,000 across Etherlink ($10k), Stellar ($10k), and NEAR ($10k) categories.

Solution

CORE ARCHITECTURESmart Contracts (Solidity):FusionPlusEscrow.sol - Atomic swap escrow with hashlock/timelock securityDeployed to Ethereum Sepolia (0xb3998845F9C5417D4F4A7aB42B71303ac7C2A174)Deployed to Etherlink Testnet (0x965359e7245fa048b4d0200081925FF3EFC08C88)Gas-optimized: 146k gas for createSwap, 66k gas for completeSwapOpenZeppelin security patterns with ReentrancyGuardCross-Chain Coordination (JavaScript):Bridge coordinator orchestrates multi-chain transactionsWeb3 integration with ethers.js v6 for transaction handlingAutomatic network switching and transaction monitoringEvent-driven architecture for real-time status updatesFrontend (React/Next.js):Modern Web3 interface with MetaMask integrationReal-time swap status tracking and transaction monitoringResponsive design with gradient UI and smooth animationsError handling and user-friendly transaction flowsSPONSOR TECHNOLOGY INTEGRATION1inch Fusion+ Integration:Atomic swap mechanism based on 1inch's hashlock/timelock designDutch auction pricing model for competitive resolver biddingMeta-order format compatible with 1inch resolver networkGas-adaptive pricing that adjusts to network conditionsEtherlink Integration:Native EVM compatibility allows direct Solidity deploymentSub-second finality for faster cross-chain settlementsLow-cost transactions (1000x cheaper than Ethereum)Seamless MetaMask integration with custom network configurationStellar Integration (Soroban):Rust smart contracts using soroban-sdk v20.0.0Cross-chain atomic swap implementation with event emissionMulti-chain bridge architecture supporting EVM ↔ Stellar swaps5-second finality for rapid settlementNEAR Shade Agent Integration:TEE-powered autonomous solver using NEAR's Shade Agent FrameworkChain Signatures for trustless multi-chain account controlRust implementation with near-sdk v4.1.1Remote attestation for cryptographic verification of TEE integrityPARTICULARLY HACKY/NOTABLE IMPLEMENTATIONSSecret Management: I implemented a sophisticated secret revelation mechanism where:User generates cryptographic secret locallyHashlock created with keccak256(secret)Secret revealed only after both escrows are created and finality confirmedAutomatic timelock refunds if process failsMulti-Chain State Synchronization:Custom event monitoring across multiple RPC endpointsFinality lock periods adjusted per blockchain (12 blocks for Ethereum, 1 block for Etherlink)Race condition prevention through proper transaction orderingGraceful degradation if any chain becomes unavailableGas Optimization Techniques:Packed structs to minimize storage slotsAssembly-optimized hash verificationBatch operations where possibleDynamic gas estimation with fallback mechanismsTEE Integration:Worker agent verification through remote attestationCode hash verification ensures only approved agents can executeStateless design allows multiple TEE instances without coordinationFailover mechanisms if primary TEE becomes unavailableDEVELOPMENT TOOLCHAINHardhat for smart contract development and testingFoundry for gas optimization and fuzzingReact/Next.js for frontend with TypeScriptethers.js v6 for Web3 integrationCargo for Rust contract compilation (Stellar/NEAR)TESTING & DEPLOYMENT100% test coverage with integration testsHardhat gas reporter for optimization trackingMulti-network deployment scripts with verificationAutomated testing across all supported chainsThe most challenging aspect was coordinating atomic operations across three different blockchain architectures (EVM, Stellar, NEAR) while maintaining security guarantees. I solved this through careful state machine design and cryptographic commitment schemes.