{"id":8706,"date":"2022-06-08T21:00:00","date_gmt":"2022-06-08T21:00:00","guid":{"rendered":"http:\/\/ci02a33c516000269e"},"modified":"2025-01-28T15:25:37","modified_gmt":"2025-01-28T15:25:37","slug":"how-to-use-bitcoin-coldcard","status":"publish","type":"post","link":"https:\/\/bitcoinmagazine.com\/guides\/how-to-use-bitcoin-coldcard","title":{"rendered":"An Easy Guide To Use The ColdCard Bitcoin Hardware Wallet"},"content":{"rendered":"
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Make sure you go through the other piece \u201cUsing Bitcoin Hardware Wallets<\/a>\u201d first. I will skim through some steps and focus mostly on what is specific to ColdCard here.<\/p>\n

This guide will be appropriate for the ColdCard MK3 and the newer Mk4.<\/p>\n

Purchasing<\/h2>\n

Buy the device directly from the manufacturer, Coinkite<\/a>. This is mandatory; don\u2019t buy from Amazon, Ebay or used, to eliminate the possibility of tampering by a scammer who may later try to steal your bitcoin. You\u2019ll need to get a micro SD card as well (the smallest and cheapest will do) and for this Amazon is probably your cheapest option (or locally and quicker, Walmart or Target, etc, also usually carry them). You\u2019ll need a connection cable as well, as one does not come with the device. You might have one lying around from an old phone, or just buy one.<\/p>\n

The Coldcard Mk4 has a USB-C connection attached to the shell, and the Mk3 has a micro USB connection. You need to source your own USB cable that matches the device and your computer\u2019s USB port type.<\/p>\n

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For example, if you use a modern Mac, it\u2019ll have USB-C ports like the ColdCard does, and you\u2019ll need a cable like this:<\/p>\n

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For the Mk3 ColdCard and a computer with regular USB ports, you\u2019ll need a cable with micro USB and regular USB, like this:<\/p>\n

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In addition to the cable, you\u2019ll need a 5-volt charger, like the ones most phones use. You can connect your wallet to the computer for power, but we want to avoid that if we can, for optimal security.<\/p>\n

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When you place your order with Coinkite, ideally you shouldn\u2019t ship it to your home address, as the packaging (available to see by the entire delivery distribution chain) states that the content is a \u201cColdCard calculator.\u201d You don\u2019t want to reveal to the world that you own bitcoin, and where you live. So, use a fake name, and ship it to your place of work, or a P.O. Box. This is best practice, but probably not a devastating error if you don\u2019t.<\/p>\n

Setting Up The ColdCard<\/h2>\n

When the device arrives from Canada, make sure you inspect the tamper-evident bag for any disturbance\/compromise. There is also a number on the bag \u2013 keep it, as the device will require you to compare that number with a number the device provides from its memory, to ensure you are receiving the correct device, and not a swapped one.<\/p>\n

Power on the device, and read everything the device presents to you carefully. The keypad has arrows; use them to scroll down to the bottom of all messages. Sometimes at the end of a message, it will get you to press a specific number to prove you read the message. If you didn\u2019t read that and pressed the checkmark to proceed, you\u2019ll loop back to the start and you\u2019ll think the device is faulty.<\/p>\n

You\u2019ll be given instructions to set a PIN. The naming of the PIN is unfortunate and a bit confusing, and I\u2019ll explain. There are two PINs in fact. When you turn on your device, you\u2019ll be entering PIN-1. You will then be presented with two \u201cphishing\u201d words that are unique to your device. The words will be the same every time, and you just need to confirm you recognise those words. Recognising the words confirms you put the correct PIN-1, and that the device is really yours and hasn\u2019t been swapped without your knowledge. Once you know the device is yours, the next prompt is to enter PIN-2.<\/p>\n

The ColdCard device calls PIN-1 the PIN prefix, and when prompted for PIN-2, it says \u201center rest of PIN.\u201d<\/p>\n

When setting PIN-1 or PIN-2, you can choose 2-6 digits for each PIN.<\/p>\n

You will then be presented with the option to create a new wallet or \u201cimport existing\u201d (restore a wallet). I will go through creating a new wallet. The device will give you 24 words, one at a time. Write them down in order, and then you\u2019ll be asked to confirm the words. Just work through the prompts. Remember to make a duplicate of these words, and store the two copies in different locations to prevent total loss from a catastrophe such as a fire.<\/p>\n

Once you are finished, the device will show you the top menu which reads \u201cReady to Sign.\u201d You can then disconnect the device. Reconnect and make sure you get the hang of turning it on and entering your PIN numbers.<\/p>\n

About Passphrases<\/h2>\n

A \u201cwallet\u201d has several meanings. Here I\u2019m using it to describe the unique collection of 2^32 addresses that belong to the<\/p>\n