UPDATE (22nd December 13:35 GMT): BTChip has now merged with Ledger.

BTChip and GreenAddress have teamed up to launch a USB bitcoin hardware wallet designed to offer multi-signature security on a budget.

Named HW.1, the smartcard-based USB wallet was created by BTChip with security and user experience in mind. The device features multi-signature functionality provided by bitcoin wallet GreenAddress.

BTChip founder Nicolas Bacca said the device should appeal to users frustrated with the bitcoin wallets’ current security policies, saying:

“We’re pleased to be the first company to bring affordable banking grade security, while preserving bitcoin user-centred principles. And, with GreenAddress, you are protected by both the card and by the multisig provided by the wallet. It makes it very, very easy for you to access your coins.”

Bacca argued that the multisig feature enhances the user experience, as transactions are made easier, safer and faster and that the use of two-factor authentication offers a second layer of security.

USB and USB on-the-go functionality

The HW.1 can be used on standard USB ports through a Chrome app running on Windows, Mac OS X, Android or Linux. It can also be used on Android devices with USB on-the-go (OTG) functionality, including a wide range of smartphones and tablets.

Lawrence Nahum, co-founder and chief executive of GreenAddress explained:

“A combination that brings the best of two worlds: multisig and hardware wallets. I expect a lot of people to be using them. Both our Chrome app and Android app support the HW.1 with the latter in final testing and via full USB ports or micro USB OTG adapters.”

Nahum says USB OTG functionality has been tested on several popular devices, including the Samsung Galaxy S5, S3, Google/LG Nexus 5 and even the old Nexus S. The app requires Android 4.x.x to run.

Security

Nahum described GreenAddress as one of the most promising and innovative bitcoin wallet platforms, with support for multisig and HD (BIP32) features. The HW.1 is based on an open-source API available on GitHub and it is compatible with Electrum 2.0.

Nahum told CoinDesk that the recently publicised BadUSB vulnerability, an exploit that turns USB-connected devices to highly programmable attack platforms, does not affect the HW.1 wallet.

The wallet is intended to be used even in situations in which the user doesn’t trust the computer being used to transact, as it handles man-in-the-middle attacks, Nahum explained. In the case that it’s used in conjunction with GreenAddress, the user may receive an email or SMS with a two-factor authentication code.

When the HW.1 device is used with the Electrum wallet, users can verify transactions on a separate computer before making signatures, thereby making it more user friendly with GreenAddress, Nahum continued.

He said:

“It means people still have to backup once they wallet details but then don’t need to remember long mnemonic passphrases. They can bring their wallet with them at all times as it fits a legacy wallet.”

The HW.1 wallet is priced at €20 with standard shipping, while registered shipping will cost €10 extra. The company also has a time limited launch offer, whereby early adopters can get two wallets for the price of one.