Paper Wallet
A paper wallet is a Bitcoin private key and address printed on a piece of paper. Once considered a cold storage method, paper wallets are now widely discouraged due to numerous security pitfalls and the availability of far superior alternatives.
How It Works
A paper wallet is created by generating a Bitcoin key pair and printing the private key (usually as a QR code and WIF string) alongside the corresponding address on paper. The idea was simple: if the key never touched an internet-connected device after generation, it was cold storage. In theory, this works. In practice, paper wallets have caused massive amounts of lost bitcoin.
The first problem is generation. Most paper wallet generators run in a web browser, which is a hostile environment for cryptographic key generation. Even offline browser-based generators can be compromised through supply chain attacks, cached malware, or insufficient entropy. The second problem is spending: when you spend from a paper wallet, you must import the private key into software, which exposes it to whatever device you use. If you spend only part of the balance, the change goes to a new address — but many users do not realize this and think the remaining funds are still on the paper wallet.
Paper itself is fragile. It burns, degrades in water, fades over time, and can be easily damaged. For the same cost as a printer cartridge, you could buy a metal backup plate. And for not much more, you could buy a proper hardware wallet that eliminates every single issue paper wallets have. There is no good reason to use a paper wallet today.
Key Points
- Private key and address printed on paper — a deprecated cold storage method
- Dangerous to generate: browser-based generators are a security minefield
- Spending pitfall: change goes to a new address, causing unexpected fund loss
- Paper is fragile — vulnerable to fire, water, fading, and physical damage
- Hardware wallets are superior in every way — do not use paper wallets