🧙 Preview in Edge Version only!
COLDCARD® can act both as signer and coordinator in Bitcoin Secure Multisig Setup (BSMS). Read more about BSMS in BIP-129.
Navigate to Settings -> Multisig Wallets -> BSMS (BIP-129)
.
Select Coordinator
.
Select Round 1
.
Choose number of signers (N). Max is 15.
Choose threshold (M). Max is 15 but has to be smaller or equal to N chosen in previous step.
Select desired address format. Press OK to continue with native segwit (p2wsh) or press (1) to use nested segwit (p2sh-p2wsh).
Select desired encryption type. Press:
Summary of coordinator round 1 and tokens, if any, are displayed. Press OK if correct or X, to abort.
If coordinator wants to participate in current BSMS setup also as a co-signer, number (1) can be pressed here to use logical shortcut and immediately perform Signer round 1
with current active key (check signer round 1 from step 5. to the end). Press OK to continue normally.
If STANDARD or EXTENDED encryption was chosen, token file/s will be exported (SD/VDisk). Token file has pattern of bsms_{first four token hex characters}.token
. There is a possibility to export via NFC as well.
At this point BSMS coordinator round 1 is registered and visible in the menu. Menu item consists of {index} {M}of{N}_{addr_fmt}_{encryption_type}
.You can click on it to see summary again if you choose Detail
, or delete it if something went wrong during the configuration with Delete
. Round 2
is also accessed from specific registered coordinator round 1.
Settings -> Multisig Wallets -> BSMS (BIP-129)
.Select Signer
.
Select Round 1
.
If STANDARD or EXTENDED encryption was used, import token. If no encryption was used press (2) to import token manually and then press (3) to choose unencrypted BSMS. When using encryption you can import token manually as hex or decimal number or choose classic way via SD/NFC/Vdisk.
ColdCard signer account {account number chosen in previous step}
.bsms_sr1_{first four token hex characters}.dat
. Files from STANDARD BSMS do not contain token hex prefix bsms_sr1.dat
and for NO_ENCRYPTION BSMS the pattern is: bsms_sr1.txt
.At this point, new menu item is created in Signer menu that consists of {index} {first four token hex characters}
. After clicking on particular signer menu item you can choose to view token with Detail
, remove registered signer round 1 with Delete
, or start signer round 2 with Round 2
.
Settings -> Multisig Wallets -> BSMS (BIP-129) -> Coordinator
.Select specific coordinator menu item created in coordinator round 1 and select Round 2
.
You will be prompted from where you want to import signer round 1 files (SD/VDisk/NFC).
Next prompt is asking whether you want to try collect signer round 1 files automatically or proceed manually - picking each file on its own. Keep in mind that auto-collection is only possible if files are imported from SD card or Virtual Disk. If you have chosen NFC you need to provide files manually one by one. This could be really annoying if trying to create big multisigs. It is probably best to use SD/Vdisk in this case. Auto-collection also requires you to provide files in specific format and with other restrictions:
bsms_sr1_{first four token hex characters}.dat
.bsms_sr1.dat
. Keep in mind that if you have more signer round 1 files from different BSMS, there will be attempt to decrypt all of them. Best option is to have on the medium only those that are needed - but it is not necessary - will just take longer.bsms_sr1.txt
and you need to have only files from current BSMS on the medium. If you also have other files from different unencrypted BSMS on the medium, auto-collection will fail, as we have no idea which one to choose.If auto-collection fails - you will be prompted to add all the files manually, asked for specific signer round 1 file with first four characters of respective token (or you can exit here, adjust file names and try again).
After all signer round 1 files are imported and validated, coordinator round 2 file/s (descriptor) is/are ready for export via SD/VDisk/NFC. If STANDARD encryption is used, only one file is exported with pattern bsms_cr2.dat
, if EXTENDED encryption is used, number of exported files will equal the number of signers (N) as each has its own token. It is needed to export files encrypted with each participant's own token. File pattern for EXTENDED encryption is bsms_cr2_{first four token hex characters}.dat
. For NO_ENCRYPTION BSMS only one file is exported with pattern of bsms_cr2.txt
.
Settings -> Multisig Wallets -> BSMS (BIP-129) -> Signer
.Select specific signer menu item created in signer round 1 and select Round 2
.
Choose from where should be the coordinator round 2 file imported SD/VDisk/NFC and import it.
If everything validates, you will be prompted to accept creation of new multisig wallet with name composed of bsms_{last four characters of descriptor checksum}
. After inspection, press OK to approve multisig import or press X to cancel.
After confirmed import, signer menu item created in signer round 1 is removed and new multisig wallet is succesfully imported.
We've found relevant search results.