Cold Wallet

Definition

A cold wallet is a cryptocurrency wallet that stores private keys entirely offline — on a dedicated hardware device that never connects to the internet, or on a paper record. Because the keys are not accessible from any online system, cold wallets are resistant to remote attacks.

Key Characteristics

• Offline: Private keys never touch the internet
• Secure: Immune to remote malware and phishing attacks
• Requires physical access: Transaction signing requires the physical device
• Best for: Long-term storage and significant holdings

Types

Hardware Wallets

Dedicated physical devices that generate and store private keys in a secure element. Popular options: Ledger, Trezor, ShapeShift KeepKey.

Security properties:

• Keys generated and stored in tamper-resistant hardware
• Transactions signed on the device, private key never exposed to host computer
• PIN protection + optional passphrase

Paper Wallets

A physical printout or handwritten copy of a private key or seed phrase, stored offline.

Security properties:

• No digital attack surface
• Vulnerable to physical theft, fire, water, loss
• Not recommended without metal backup for non-trivial amounts

Related

• [Hot Wallet](/glossary/hot-wallet/)
• [Self-Custody](/guides/bitcoin-self-custody-tradeoffs/)
• [Seed Phrase](/guides/seed-phrases-what-they-are-and-how-people-lose-them/)