Roundtable_023 - Staying Humble

— Coldcard firmware entropy failure generated weak keys (equivalent to 8-character passwords) on Mark 3+ devices, enabling mass GPU brute-forcing of wallets in minutes instead of requiring computational energy exceeding the sun's output.

— Transition from open-source (GPL) to source-available firmware in 2019–2021 reduced scrutiny and may have introduced the bug; the fallback pseudo-random number generator should never have existed as a design choice.

— AI and LLMs have fundamentally changed vulnerability discovery: attackers now require only hours with language models to find and exploit weaknesses that previously required deep expertise.

— Hardware manufacturers must adopt continuous entropy validation testing (running devices 24/7 generating seeds) and include physical dice with every device to give users agency over randomness.

— Multi-signature setups with at least one compromised key remain vulnerable; users must spend all funds at once via high-fee transactions or out-of-band mining to avoid revealing script hashes that expose remaining keys.

— Open-source code is non-negotiable for security-critical software; source-available licenses enable regulatory capture and reduce community auditing that would catch such failures.

— If you hold a Coldcard Mark 3, 4, 5, or Q generated without dice rolls: immediately move funds off the device using any software wallet (Sparrow, Green, Aqua, Nunchuk). New firmware fixes the entropy issue only for future key generation; previous seeds remain compromised.

— For multi-signature setups using any Coldcard: spend all funds in a single high-fee transaction or coordinate an out-of-band transaction to avoid exposing the script hash on-chain, which would allow attackers to brute-force your remaining keys.

— Add physical dice rolls to your key generation workflow going forward, regardless of hardware manufacturer claims about entropy; this removes trust in any single device and aligns your practice with proven cryptographic principles.