Definition
Security properties of hardware wallets used for cryptocurrency self-custody — covering secure element design, firmware RNG/entropy, air-gap assumptions, and supply-chain trust.
Key Points
- 2026-07-30: coldcard RNG fallback shows air-gapped devices can still lose funds if seed generation is enumerable offline
- Firmware updates do not heal weak historical seeds
- Model/firmware scope disputes matter for user guidance (coinkite vs block)