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Questions tagged [coldcard]

Coldcard is an open source hardware wallet built by Coinkite. A hardware wallet (or hardware signer) generates, stores and signs with cryptographic keys.

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What is the difference between PSBT support in Coldcard and Trezor?

The 10x Security Bitcoin Guide says that the only two hardware wallets support BIP174 (partially signed Bitcoin transactions, or PSBT). However, this Reddit thread says that "You can use PSBT with Trezor via HWI". This Github issue elaborates. What…
Sergei Tikhomirov
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What is an extended fingerprint (xfp) and how does it differ from an xpub?

Coldcard requires the xfps of all of its cosigners to be able to verify and sign multisig transactions. Providing the coldcard with just the xpubs is not enough, which I believe to mean that the xfp can't be gleaned from the xpub. So, what is an…
paddy
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Verify Receive and Change Addresses

I run a coldcard with Electrum and Electrum-Personal-Server. As I understand it, we use hardware wallets because we don't trust our laptops. However, I've only been able to verify the sending addresses on the coldcard's screen when I sign…
McMurdo
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What does bitcoin.org mean when they say about Coldcard Wallet "the final software was not built deterministically like Bitcoin Core"?

I am looking at hardware wallets to store my Bitcoins, and Coldcard Wallet Mk3 seems like a great option. However, at looking at info about it at bitcoin.org, it says that the software is not built deterministically like the consensus Bitcoin Core…
Ander Aristondo
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How to best practice restoring a wallet in bitcoin core

I have a test wallet in bitcoin core that I want to play around with and get comfortable with before I move my btc from blockstream green wallet. I primarily use that wallet because so far it has been easy to understand. So I have created this core…
Anders Kitson
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Is it possible to use Electrum to create a multisig wallet with a trezor and an airgapped coldcard?

I set up a 2-of-3 multisig using Electrum, a Trezor, and a Coldcard. During testing, I ran into issues using the Coldcard to sign. My approach: (On Electrum) File -> New/Restore -> Multi-signature wallet -> Use a hardware device Plug in Trezor,…
paddy
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Need help moving funds from legacy address, Coldcard won't sign psbt

I'm in needs of help moving funds from an legacy address, single sig: I exported my Coldcard's xpub to Bluewallet. Bluewallet derived an address from that xpub onto which I received funds. Unfortunately, Bluewallet gave me a legacy address and I…
honeypotGhost
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Is multisig wallet simply a combination of many singlesig wallets?

I’m trying to create a multisig wallet for the first time. My pre-understanding is that multisig wallet is simply a combination of many singlesig address. So for example I have 3 existing singlesig wallets: electrum wallet Bluewallet Coldcard…
bbnn
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Why these 2 pubkeys start equal?

I generated a seed into my coldcard, wrote down its pubkey: xpubABCDEFGHIKL--------------------------------------------------- then I erased everything and generated a new seed, and wrote down its…
Guerlando OCs
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Is this scheme for multisig audit of Trezor + Coldcard ok?

My plan is to make a multisig between coldcard and trezor. I want to audit and verify that I indeed own the 2 keys of these wallets, using a raspberry pi zero (no wifi/bluetooth by definition) on a very old HDMI tv with no internet either, and using…
Gatonito
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How can I recover funds recovery from coldcard?

I recently bought a Coldcard mk4 and did some tries to understand how it works. I moved a tiny amount to test it but now I can't recover it. What I think happened is: I exported the wallet created with the CC and imported in Blue Wallet app on my…
difismak
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How do you import an air-gapped created multisig wallet from Coldcard to Electrum?

I went through the process of creating a 3/5 multisig with coldcard, air gapped. I generated an electrum wallet file, but now I'm struggling to figure out how I use electrum to import the multisig wallet (as a watch-only). Thanks
karns
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Sent funds to ColdCard BIP 32 address, how can I transfer them out to a different address?

The Setup I purchased a genuine ColdCard, verified its authenticity, set it up, backed up my key and all that good stuff. I then wanted to transfer some BTC from an exchange but I was being paranoid and did not want to even connect a MicroSD from my…
BearsEars
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Setting Up Multisig Correctly

I'm looking into setting up a multisig setup using Sparrow, and wanted to see if anyone can find any flaws in my set up, and potentially accessing my funds if I lose a key. set up = 2 of 3 Key store 1 = Passport HWW Key store 2 = Cold Card HWW Key…
Paranoid BTC Novice
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When using a hardware wallet, how do I know that the change address is one that I own?

When signing a transaction on my coldcard, I see a change address that is not listed (at least on the first 30 addresses) on my coldcard. I believe coldcard would only allow me to sign a transaction to a change back address that I own, but how do I…
Guerlando OCs
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