Coldcard's 65-Key Press Fix Leaves Compromised Seeds Exposed

The 65-press barrier

Coldcard's new firmware demands 65 physical key presses to generate a single wallet. That is the first number any user sees after updating to 5.6.1 or 1.5.1Q, five times the previous 12-press flow. Coinkite shipped the change to close a seed-generation flaw that could leak entropy on affected devices. The fix works for new wallets. It does nothing for the keys already in circulation.

What the exploit actually broke

The vulnerability lay in the hardware random-number generator during seed creation. On firmware 5.0.0 through 5.6.0 (Mk4) and 1.0.0 through 1.5.0Q (Mk3), an attacker with physical access or supply-chain interception could reduce the effective entropy of a 24-word seed. Coinkite's advisory confirms the flaw was in the RNG seeding path, not the BIP-39 derivation itself. Patching the RNG for future seeds is a one-line firmware change. Recovering entropy that already left the device is not possible in software.

Why 65 presses changes the threat model

The 65-press requirement forces users to verify each word of the generated seed on the device screen before confirming. That raises the bar for evil-maid attacks during initial setup, an adversary now needs sustained physical control for minutes, not seconds. But it adds friction for every legitimate user, every time they initialize a Coldcard. The Mk4's keypad is not designed for high-frequency entry; early adopters report hand fatigue and mispresses after the 40th confirmation. Coinkite has not published usability telemetry for the new flow.

Who holds the bag

Anyone who generated a seed on vulnerable firmware holds a key that may have reduced entropy. The only remediation is on-chain migration: create a new wallet on patched firmware, then send every UTXO to the new addresses. Coinkite has not issued a migration tool, a deadline, or a key-rotation policy. The burden falls entirely on the user to recognize the risk, build a new wallet, and pay the network fees to move funds. For multisig participants, every cosigner must rotate simultaneously, a coordination problem the firmware does not solve.

What could force a timeline

Three events would change the calculus: a public proof-of-concept that extracts seeds from compromised devices, a documented theft traced to the RNG flaw, or a Coinkite advisory that sets a hard deprecation date for old firmware. Absent those, the 65-press wall is a forward-looking control, effective for new users, invisible to the installed base.