• 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


Video Tutorials

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