Learn how to upgrade here >
Current Version of Coldcard Firmware
2019-05-13T1631-v2.0.4-coldcard.dfu built May 13, 2019.
Release Notes (v2.0.3 – 2.0.4)
- Transaction signing speed improved by about 3X.
- Will warn if miner's fee is over 5% of txn amount (was 1% before). Hard limit remains 10% (configurable, can be disabled completely).
- Robustness: Tighten stack-depth checking, increase heap size, shuffle some memory.
- Bugfix: Transactions with more than 10 outputs were not summarized correctly.
- Bugfix: Consolidating transactions that move UTXO within same wallet are shown better.
- Bugfix: Better recovery from too-complex transaction errors.
- "Don't forget your PIN" warning message is more bold now.
- (in 2.0.4) Bugfix: Clearing duress PIN would lead to a error screen.
- (in 2.0.4) Bugfix: Advanced > "Lock Down Seed" command didn't work correctly.
- (in 2.0.4) Bugfix: Importing seed words manually didn't work on second try (thanks @duck1123)
Older Changes (2.0.0 – 2.0.2)
- BIP39 Passphrase support: enter up to 100 characters to create new wallets from your existing seed words. Each is a completely independant wallet to Electrum and PSBT files, so please make note of the extended master fingerprint (eight hex digits).
- Support for Mark2 hardware, with membrane keypad replacing touch interface.
- Adds activity light during MicroSD card read/write (Mk2 only)
- New command: "Lock down seed" which converts BIP39 seed words and passphrase into the master xprv and saves that as new wallet secret. Locks in the passphrase, deletes seed words.
- New bootrom, version 1.2.1 with Mk2 hardware support and improved one-wire bus MitM defences.
- Bugfix: extra keypress occurs during certain interactions involving key repeat.
- (in 2.0.1) bugfix: underscore/space indicator shown on Settings > Idle Timeout menu
- (in 2.0.2) Page up/down on long text displays with 7/9 keys
- (in 2.0.2) Public summary file now includes extended master key fingerprint near top of file.
- (in 2.0.2) Bugfix: signing larger transactions could fail due to lack of memory
Older releases and their changes are listed here, the source code, and much more be found in our repository on github.
How to upgrade
Advanced: Verify Your Downloads
The release binaries may be verified using this clear-signed text file and GPG. The command is:
gpg --verify signatures.txt
Please look for signing key:
Don't forget to run SHA256 over the DFU files themselves, because that compares your actual file contents to what we signed.
Github.com is also protecting us because it verifies on all commits against the developer's public keys, and keeps a history of changes.
The upgrade menu allows you to load updated firmware onto the Coldcard.
The menu allows loading an upgrade file from a MicroSD card, but it can also be done using the command line tool, or from the Electrum plugin.
How to Upgrade
- Show Version
- Displays the version numbers that you have already.
- From MicroSD
- Select an upgrade file from MicroSD card and start the process.
- Bless Firmware
- Mark the contents of flash memory as "approved" and light the green "Genuine" light.
You need a
DFU file for upgrades. It's about 690k in size and should have the
The latest firmware will always be available in Github:
All upgrade files must be signed by a Coinkite Inc. approved key, or the Coldcard will refuse to load and run them.
This command is not typically needed, but can be used to set the genuine/caution lights to green. Note that only the main PIN holder can do this. A normal firmware upgrade sequence does not require this action, but if the unit is powered down between installing the upgrade and the first successful login, then the light will be red and stays red until this command is used.
In general, it may not be possible to downgrade (return to an older release). Some releases will set a "high water mark" so the bootloader that will block any downgrade to earlier versions. We will do this if a bug or security problem with an obsolete release is identifed.