Huge Mk4 Release! Version 5.1.0

MicroSD as 2FA, Import TAPSIGNER as main/ephemeral seed, Detached sig for exports, App-specific deriv paths, Import/Export overhaul, incl Samourai POST/PRE-MIX, Opt to save pw 4 next backup & more

New Features

• “MicroSD card as Second Factor”. Specially marked MicroSD card must be already inserted when (true) PIN is entered, or else seed is wiped. Add, remove and check cards in menu: Settings -> Login Settings -> MicroSD 2FA

• Import TAPSIGNER encrypted backup as main or ephemeral seed, for PSBT signing. This is a great way to safely use the key previously held inside a TAPSIGNER, because the COLDCARD can take over the signing that used to be done by the card.

• Detached Bitcoin signature files for most exports.

  • Files exported are now signed with a detached signature. Look for a .sig file with the same name, and verify signature with your favourite Bitcoin tools. See “Signed Exports” in docs/msg-signing.mdfor more information.

  • Coldcard can now verify signed files:

    • SD card and Virtual disk Advanced/Tools -> File Management -> Verify Sig File

    • NFC Advanced/Tools -> NFC Tools -> Verify Sig File

  • Learn more here

  • Related new website: Check your Bitcoin signatures here

Enhancements

• Address Explorer:

  • Application-specific derivation paths in Address Explorer -> Applications

  • Bugfix: Change value was ignored when generating addresses file

• Imports:

  • Add import multisig wallet via Virtual Disk

  • Add import extended private key via Virtual Disk and via NFC

  • Import seed in compact/truncated form (just 3-4 letters of each seed word)

  • Import extended private key as ephemeral seed

• Export:

  • Samourai POST-MIX and PRE-MIX descriptor export options added

  • Lily Wallet added

  • Ability to export all supported wallets via NFC (instead of SD card only)

  • Change electrum export file name from ‘new-wallet.json’ to ‘new-electrum.json’

  • Allow export of Wasabi skeleton for Bitcoin Regtest.

• Backup Enhancement:

  • Option to save the backup file’s encryption password for next backup. Then next backup is quick and simple: no need to record yet another 12 words.

• During seed generation from dice rolls, enforce at least 50 rolls for 12 word seeds, and 99 rolls for 24 word seeds. Statistical distribution check

• Single signature wallet generic descriptor export Advanced -> Export Wallet -> Descriptor. Both new format with internal/external in one descriptor <0;1> and standard with two descriptors are supported. added to prevent users from generating low-entropy seeds by rolling same value repeatedly.

• Docs: Add docs/rolls12.py script for verifying dice rolls math for 12 word seeds.

Bug Fixes

• Offer import/export from/to Virtual Disk in UI even if SD Card is inserted.

• Recalculate extended key saved in settings upon chain change (BTC, XTN, XRT).

• Provide correct derivation path (m/84’/1’/0’) for testnet Wasabi export.

• Properly display UX checkmark only if testnet (XTN, XRT) is enabled in Settings- > Danger Zone -> Testnet Mode.