How does a typical transaction take place using the KeepKey?
Users initiate transactions in the computer client just as they did before using a KeepKey. The computer client no longer stores private keys, and is therefore not able to sign transactions. The computer client must pass transactions to the KeepKey, requesting they be signed. Once a request is received by the KeepKey, it displays the transaction details and prompts the user for manual confirmation via a button. Once approved by the user, the transaction is signed and returned to the computer client to be announced on the Bitcoin network.

Do I need to install drivers in order to use my KeepKey?
KeepKey is a USB HID-class device (like keyboards, mice, and game controllers). It doesn’t require drivers when used on Windows, Mac, or Linux. Some applications with limited USB access, however, may require additional software to work with KeepKey. For example, our Google Chrome extension requires an additional Chrome app in order to communicate with the device. This is an easy installation, though, and our Chrome extension will guide you through it.

Do I need special software in order to use my KeepKey?
KeepKey must be used in conjunction with supported computer clients. At this time, KeepKey works with our Chrome app, as well as Electrum and Mycelium.

How do I backup my KeepKey incase it is lost or stolen?
When your KeepKey is initialized, you are given an opportunity to write down a recovery sentence. This recovery sentence is your KeepKey’s backup. If your KeepKey is lost or stolen, you can recover your private keys using this recovery sentence. KeepKey supports the account hierarchy standardized in BIP 44, so any software that supports BIP 44 can recover your funds. You can also recover your private keys onto a new or empty KeepKey with the recovery sentence.

What is the difference between my PIN, my recovery sentence, and my passphrase?
Your PIN prevents unauthorized users from reviewing balances and doing transactions. Your recovery sentence is an encoded version of your private key using normal dictionary words. This sentence should be kept secret: anyone knowing it can easily gain access to your bitcoins. Your passphrase is an additional word appended to your recovery sentence that is never stored on your KeepKey. We do not recommend using the passphrase feature unless you completely understand the consequences of using it.

If I forget my PIN, do I still have access to my bitcoins?
If you forget your PIN, you will be locked out of your KeepKey. You will, however, still be able to recover your bitcoins with the recovery sentence.

How many private keys and wallets can be stored on my KeepKey?
KeepKey supports BIP32 wallets, or what are commonly called HD wallets. This allows KeepKey to generate and store an unlimited number of private keys. KeepKey also supports BIP44, which allows for an organization of accounts. KeepKey can support a practically unlimited number of wallets, with an unlimited number of private keys.

Can my KeepKey be cleared and reset, deleting my private keys?
KeepKey has a device wipe feature, which will delete all private keys and settings from the device. We recommend you do this prior to selling or giving your KeepKey to anyone. If the KeepKey you intend to wipe has any funds, make sure you still have your recovery sentence, because a device wipe is irreversible.

Can I sign messages with my KeepKey?
KeepKey supports message signing; the process is very similar to transactions. In a computer client that supports KeepKey and message signing, you first create the message you intend to sign and choose the address to use for the signature. Your computer client passes the message and chosen address to the KeepKey, which in turn displays it and prompts the user for manual confirmation. Once confirmed, the signed message is returned to the computer client.

Why does the KeepKey have such a large display?
The KeepKey requires a display, first and foremost, to show the user the transaction they are confirming to be signed. We designed KeepKey to have a large display because we felt it critical that transaction details be clear and legible. A small display that is difficult to read discourages users from carefully reviewing each detail in a transaction.

Can I use my KeepKey with multiple computers?
Your KeepKey can be used with multiple computers, because it stores and secures all of your Bitcoin private and public keys: the information required to view balances and do transactions. Computer clients that have not seen your specific KeepKey before may take longer to load as it must sync the transactions corresponding to your KeepKey.