DePHY is a decentralized, low-latency off-chain network designed to bridge the physical and blockchain worlds through verifiable and composable digital interactions. It addresses the gap in Web3 for authentic, real-world data integration, using advanced security measures like Device ID based on Trustzone-Optee and a decentralized data access framework. DePHY enables devices to securely and reliably contribute to the blockchain ecosystem, facilitating real-world actions to be translated into valuable digital assets.