Hardware identity primitive for Arbitrum Stylus — binding ESP32-S3 silicon to on-chain execution. Sybil-resistant DePIN verification without TEE or secure elements.
DePIN networks distribute millions in rewards assuming their nodes are real, distinct hardware. Not one of them can prove it on-chain. A single actor running virtualised instances can register hundreds of fake identities, farm rewards indefinitely, and the protocol is completely blind to it.
Stylus Hardware Anchor (SHA) is the first on-chain hardware Sybil resistance primitive for DePIN. It binds manufacturer-burned ESP32-S3 eFuse silicon identifiers directly to Arbitrum Stylus execution logic. One physical chip equals one on-chain identity, cryptographically enforced. No TEE. No secure enclave. No trusted third party. Just silicon that cannot be cloned.
Receipt verification in Solidity is prohibitively expensive at scale. Stylus WASM batch execution changes the economics entirely. At N=5 the cost is 29,748 gas per receipt, at N=10 it drops to 20,209, at N=20 to 15,419, and at N=50 to 12,564. This amortisation curve is structurally impossible to replicate in Solidity. SHA is a Stylus-exclusive primitive, not a contract that happens to deploy here.
SHA delivers four on-chain guarantees. Device-bound identity means one physical chip produces one on-chain identity derived from manufacturer-burned eFuse registers, making it unforgeable and non-transferable. Replay protection is enforced through a ReplayDetected custom error, ensuring each receipt is processed exactly once, permanently. Firmware governance restricts execution to approved firmware hashes, enforced in WASM rather than policy. Deterministic verification confirms Keccak-256 parity across the ESP32 firmware, Python middleware, and Stylus contract, validated across more than 10,000 test vectors.
The contract is live on Arbitrum Sepolia at 0xD661a1aB8CEFaaCd78F4B968670C3bC438415615 with 89 or more real transactions on-chain. The full codebase is open source at https://github.com/orthonode/Stylus-Hardware-Anchor. This is not a concept. Working hardware is talking to a working Stylus contract and producing real on-chain state right now.