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:

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.

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:

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.

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:

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.