Architecting institutional Bitcoin custody systems resilient against insider theft, fee-siphoning attacks, and physical extraction.
Unlike account-based blockchains, Bitcoin's UTXO (Unspent Transaction Output) model requires distinct transaction construction and signature logic. Blindly signing byte blobs allows compromised application servers to drain wallets by inflating miner fees or redirecting change outputs. BitHSM addresses this through structural UTXO validation within physical hardware boundaries.
Reusing an ECDSA or Schnorr nonce ($k$) across two distinct signatures instantly leaks the private key. BitHSM strictly enforces RFC 6979 deterministic nonce generation combined with synthetic nonce blinding (BIP-340), completely eliminating nonce reuse and covert side-channel exfiltration attacks.
BitHSM integrates seamlessly with enterprise multi-signature coordinators (such as Specter, Caravan, and Unchained), validating multi-sig descriptors before appending its hardware-signed signature to PSBT bundles.