Cold Storage

Cold storage is any method of holding a private key offline, beyond the reach of internet-based attackers. Common forms include a dedicated hardware wallet or an offline computer used only for signing transactions. The defining feature is the air gap: because the key never touches an online machine in normal use, remote malware and phishing cannot steal it. Cold storage trades a little convenience for a large reduction in attack surface, which makes it well suited to larger balances and long-term holdings. To spend from cold storage, a transaction is prepared and signed in a controlled way, then the key returns to its offline rest. It contrasts with a hot wallet, which stays connected and convenient but more exposed.