Downgrade Trezor Model T Firware to restore ElectrumSV Signing Capabilities
Recently a lot of Electrum, ElectrumSV and ElectronCash users were affected by a firmware upgrade for the Trezor hardware wallet by SatoshiLabs. While it is usually great to keep your firmware up to date, the latest release 2.3.1 (or 1.9.1 for Trezor Model One) caused signing issues with Electrum and is supposed to be fixed in the next firmware update.
For users that have upgraded, this is a short guide on how to roll back the firmware. I am no security expert, but this should be a pretty save procedure as long as you trust in two tings:
- You have a backup of your Trezor wallet and can restore it from that backup.
- You trust your device to check the signature of the firware you download (if other firware is run than released by SatoshiLabs the Trezor is supposed to warn about that or prevent it even)
Disclaimer: No affiliation to SatoshiLabs or Trezor, this is just a user review.
- Connect your Trezor and go to the Trezor wallet.
- Unlock the Trezor by entering your PIN.
- Now back in your web wallet, you should check your address bar and it should show:
“https://wallet.trezor.io/#/device/SOMEHEXDECNUMBER/account/0”
4. Change the address to:
“https://wallet.trezor.io/#/device/SOMEHEXDECNUMBER/custom_firmware”
5. Before following the instructions on this tab, open a new one and paste this to download the firmware:
“https://wallet.trezor.io/data/firmware/2/trezor-2.3.0.bin”
You can check all the versions you and their history if you want
6. Now follow the instruction from the previous tab and downgrade the firmware.
7. If you downgrade from 2.3.1 you should not have to restore your wallet, if you updated from other versions, you may have to. In any case, have your backup at all times!!!
You can now use basically all the latest features of Trezor Model T with Electrum again.
This includes using a Shamir Secret Sharing backed up wallet in conjunction with Electrum. If you want to know more about that, you can check out my guide here.
If you want to see how the signing process with Trezor Model T and ElectrumSV looks, you can check out my guide.