Enhancements

• Shows QR code with BIP-85 derived entropy value if you press (3) while value shown on-screen. Thanks to @opennoms for idea. Works with 12/18/24-words, XPRV, privatekey and even hex cases.

• Offer to show QR in other places:

  • Coldcard’s main XPUB, in Advanced > View Identity

  • Seed words, during picking process (before the quiz)

  • Stored seed words: Advanced > Danger Zone > Seed Functions > View Seed Words

  • TXID of just-signed transaction (64 hex digits)

  • Encryption password for the system backup file (12 words)

• We now grind a nonce so that our signatures are always 71 bytes or shorter. This may save a byte in transaction size, and makes our signatures identical to those produced by Bitcoin Core, improving anonymity on-chain. Thanks to @craigraw for detecting this.

Bug Fixes

• On a blank Coldcard, after importing a seed phrase using the Seed XOR feature, the main menu was not updated to show system is “Ready To Sign”.

• Red caution light could happen (a false positive) if a specific sequence of firmware upgrades and reboots occured in the right order. Issue could only occur once during lifetime of any particular Coldcard.

Download the latest firmware

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Video Tutorials

We have a growing library of video tutorials on Youtube … and we’re still adding more!