Cold wallet
A cold wallet stores crypto keys on a device that is not connected to the internet, often a small dedicated hardware device. Staying offline reduces exposure to online attacks. The SEC warns that cold wallets bring a different risk: they can be physically lost or damaged.
How does a cold wallet work?
The keys are created and kept on hardware that stays offline. When you want to send crypto, the transaction is prepared on a connected computer or phone, but the signature is made on the cold device. The key itself does not need to touch the internet.
NIST observes that many users keep their keys on special secure hardware for exactly this reason. Paper backups of the recovery words are another offline form of storage.
What does a cold wallet protect against, and what not?
| Threat | Cold wallet helps? |
|---|---|
| Remote hacking of an online device | Yes, keys stay offline |
| Losing or breaking the device | No, you need a backup |
| Approving a scam transaction yourself | No, a signed transfer is final |
| A platform failing | Yes, if you hold the keys yourself |
What happens if a cold wallet breaks?
Say your device is dropped in water. The crypto is still recorded on the blockchain. What matters is whether you kept the seed phrase. The SEC notes it can restore a wallet if the wallet or key is lost, so a new device plus the words gets you back in. No backup, and the access is gone.
What are the risks of a cold wallet?
- Physical loss or damage, which the SEC names directly for offline wallets.
- A missing or exposed backup. The recovery words carry the same power as the device.
- Human error when sending. NIST notes transfers generally cannot be undone, so a wrong address or a scam approval stays final.
- A false sense of safety. Offline storage does not stop someone persuading you to sign a transfer.
Frequently asked questions
Does a cold wallet store my coins?
No. It stores keys. The coins are recorded on the blockchain, and the cold wallet holds the means to move them.
Is a cold wallet the same as self-custody?
A cold wallet you control is one form of self-custody. The SEC points out that self-custody makes you alone responsible for the keys, so backups and safe storage are your job.
Sources
- SEC, Crypto Asset Custody Basics for Retail Investors – Investor Bulletin (Dec 2025) — investor.gov (accessed 2026-10-02)
- NIST IR 8202, Blockchain Technology Overview (2018) — nvlpubs.nist.gov (accessed 2026-10-02)