Nine minutes, start to finish.
Nothing here is hidden and nothing is automated on your behalf. If a step looks like it is doing something you did not ask for, it is not this product.
Before you start
What you need
A computer you can restart. A pen. Paper, or a steel backup plate if you have one. Optionally, five dice. Nothing else — no internet, no phone, no account.
What to turn off
Unplug the network cable and switch off Wi-Fi at the hardware switch if your machine has one. The kernel has no network stack, so this changes nothing technically. Do it anyway — a habit that costs nothing is worth keeping.
Verify before you boot
Check the seal on the bag. If it has been opened, stop and email support@koini.io. Then check the stick against the published SHA-256 — instructions here, one command, two minutes.
This is the step most people skip. It is also the only step that would have caught a supply-chain substitution, which is the attack that took $160M from Wintermute in 2022 through a tool that was itself honest.
Boot
Restart, hold the boot-menu key for your machine, choose the stick. Your operating system never loads. Nothing on your internal disk is mounted, read, or touched — there is no driver present that could.
You will see a plain screen. It is deliberately plain.
Add your own entropy
The tool draws randomness from the platform CSPRNG and asserts, at runtime, that the source is what it believes it is. If that check fails it refuses to generate and says so. It will never quietly substitute something weaker.
You can also roll dice and enter the results. Your randomness is combined with the machine's through a domain-separated hash, not XOR — so a hostile or broken machine RNG still cannot sink your key, because it does not know your dice.
This is not a decorative feature. In the Coldcard failure disclosed in July 2026, the users who supplied their own dice entropy were the ones who were unaffected. It is the only defence in this bug class with a proven field record. The full story →
Write it down
Your seed phrase appears once. Write it by hand. Do not photograph it. Do not type it into anything. The screen is the only place it exists and it exists there until you power off.
The tool then asks you to type selected words back. This is not ceremony — an unverified backup is the single most common way people lose Bitcoin, and it fails silently until the day you need it.
Take your addresses
Your Bitcoin receive addresses are shown alongside the phrase. Write down the first one, or several. You will fund these from an exchange or another wallet later, from a normal computer — that is fine. A receive address is public.
Power off
Pull the plug or hold the power button. Not "shut down" — off.
RAM loses its contents when it loses power. Nothing was written to any disk, because there is no driver that could have written it. There is no swap file, because no swap was configured. There is no log, because there is no logger. This is the destruction step, and it is physics rather than a promise.
The honest caveat, for the Mac edition
On Apple Silicon the ceremony runs inside macOS, in a sealed sandbox, because those machines cannot boot from a USB stick at all. macOS keeps running underneath. Destruction there is a claim we make about our software, not a property of the hardware. It is a real product and a reasonable choice, and it is a weaker guarantee than booting. We would rather say so here than let you discover it later.