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02

What Went Wrong

Coldcard's entropy generation wasn't truly random for some devices. Instead of impossible-to-crack private keys, affected wallets generated predictable seeds. Attackers brute-forced these weak seeds and drained the Bitcoin.

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03

Was This Hardware Wallet Weakness?

No—this was a firmware bug, not a hardware failure. Hardware wallets are still the safest way to store Bitcoin. The vulnerability was in seed generation, which is now patched.

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04

Key Lesson: Firmware Matters

Unlike spot Bitcoin, hardware wallets require active maintenance. Check security advisories regularly, update firmware only from official sources, and verify that your device runs the latest patched version immediately.

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05

Multi-Sig Is Now Essential

For large holdings ($100K+), consider multi-signature setups using multiple hardware wallets from different manufacturers. This eliminates single-point-of-failure risks.

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06

What You Should Do Now

Check if your Coldcard is vulnerable using the official advisory. If so, move funds to a newly generated address on patched firmware or another secure wallet. Don't delay—attackers are actively scanning vulnerable addresses.

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07

The Takeaway

Hardware wallets remain Bitcoin's safest storage option. The Coldcard hack reminds us that security requires vigilance, regular updates, and understanding the tools you rely on.

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