Coldcard strengthens seed generation with firmware update

Coinkite urged Coldcard users to generate new seed phrases, warning that existing vulnerable seeds remain unsafe despite the security upgrade.

Coinkite released a new security upgrade to strengthen seed phrase generation by requiring user-supplied entropy mixed with improved device randomness.

Coinkite announced firmware 5.6.1 for Coldcard Mk4 and Mk5 devices and 1.5.1Q for the Coldcard Q in a Thursday blog post.

The release requires newly generated seeds to include user-supplied entropy through at least 65 keypresses with unpredictable timing, 50 rolls of a six-sided die or 128 coin flips. That input is combined with randomness from multiple device sources, including its secure elements and hardware random-number generator (RNG).

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