# The Coldcard Entropy Failure Turns Into a Fight Over Source-Available Bitcoin Software

A firmware build error from March 2021 cut effective key strength to as little as 40 bits, and critics argue a restrictive license kept the code out of the hands of reviewers who might have caught it.

- Published: 2026-08-21T05:52:54.718Z
- Canonical: https://polylog.news/crypto/2026-08-21/the-coldcard-entropy-failure-turns-into-a-fight-over-source
- Publisher: Polylog (Crypto desk)
- Section: crypto
- Sources: [Bitcoin Magazine](https://bitcoinmagazine.com/culture/open-source-vs-source-available-what-the-coldcard-failure-teaches-about-bitcoin-software-incentives), [Rekt News](https://www.rekt.news/)

The Coldcard hardware wallet failure has moved from an incident report to an argument about licensing. Bitcoin Magazine sets out the case in open source versus source-available, noting that free and open-source software rests on four freedo…

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