Cold Wallet

A cold wallet is a cryptocurrency storage method where private keys are kept offline, completely disconnected from the internet. This is the highest-security method for holding cryptocurrency. Hardware wallets like Ledger and Trezor are the most common cold storage devices, small USB-like devices that generate and store private keys internally, never exposing them to the connected computer.

When signing a transaction, the transaction details are sent to the device, reviewed on its screen, and signed internally. The private key never leaves the device. Paper wallets represent the extreme: a private key printed on paper and stored in a safe. Air-gapped computers that have never connected to the internet can also serve as cold storage. The security trade-off is convenience.

Moving funds from cold storage requires physical access to the device. For long-term holdings, this is ideal, major assets should never be exposed to internet-connected systems where malware can steal keys. Hot wallets, browser extensions and mobile apps, sacrifice security for convenience.

The best practice is keeping only spending money in hot wallets and the majority of holdings in cold storage, just as you'd keep most savings in a bank rather than your pocket.