Definition
Practice of holding Bitcoin private keys without a third-party custodian, often via hardware wallets. Security depends on seed entropy quality, firmware integrity, and operational hygiene — not merely physical air-gapping.
Key Points
- 2026-07-30: Coldcard RNG incident (~$70M) challenges “air-gapped = safe” heuristic
- Migration checklist: new seed on patched firmware, verify receive address, move funds, retire compromised seed