In the Bitcoin world, you are your own bank. Bitcoin ownership is materialized by a private key, or a private master seed. Computers are not great at protecting such data, especially considering that whenever you sign a transaction your key must be read and stored in the application memory. If your computer is compromised, then your keys are, and your bitcoins are gone forever.
Ledger Wallet protects your keys with a secure micro-processor certified against all types of attacks (both physical and logical). This technology has been used in the banking industry for decades (think credit card chips). Our hardware wallet will do all the Bitcoin cryptographic heavy lifting such as signing transactions inside its secure environment. You can therefore use your Bitcoins with maximum trust, even on an insecure or compromised computer.
Cold storage (such as a paper wallet in a physical safe) can be a very effective solution to secure your bitcoins. The benefit of Ledger Wallet is that it keeps the same level of security but adds convenience. Indeed, cold storage prevents by definition all usage of your bitcoins. As soon as you need to spend them, you’ll have to import your private keys on your computer, and you’ll have the same security problem if it has been compromised.