### Huge COLDCARD Mk4 Release! Version 5.1.0
## 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.md` for 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](https://coldcard.com/docs/sign-text-file#signed-exports)
- Related new website: [Check your Bitcoin signatures here](https://checkmsg.org/)
## 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`.
## [Upgrade here](https://coldcardwallet.com/docs/upgrade)
---
Official post https://blog.coinkite.com/5.1.0-released/
