Blockchain technology firm Blockstream, Inc. has acquired European bitcoin wallet provider GreenAddress (GreenAdressit Ltd.) for an undisclosed sum.

Founded in 2014, GreenAddress offers a per-transaction two-factor authentication, multi-signature and deterministic wallet that is claimed to deliver users unprecedented control over their transactions.

The company uses a number of systems to keep the wallet secure and yet simple, despite the fact that it does not store private keys at all. That includes quick PIN login to a wallet from any device without having to use your passphrase, and a watch-only mode that allows users to quickly check their balances or receive funds without full access to their wallet.

Post acquisition GreenAddress will continue to operate as a standalone bitcoin wallet provider with apps available for Android, iOS, and Chome; the source for the wallet will remain open source and available on GitHub.

“GreenAddress’s excellent reputation is the product of a three-person team with a deep commitment to Bitcoin,” Blockstream President Adam Back said in a blog post announcing the deal. “Their users are passionate, technically minded early adopters who have sought the highest levels of privacy and security for their bitcoin wallets.

“GreenAddress was one of the first wallets to deliver features like HD multisig, hardware wallet support, dynamic fees based on Core fee estimation, and transaction replacement,” Back added. “The team has already started on an impressive lineup of new features, too, including a new, multi-platform wallet library, privacy and security enhancements, and sidechain support throughout the platform.”

Sidechain development

Blockstream is best known as a developer of sidechain technology, blockchains that are interoperable with each other and with bitcoin that can assist in avoiding liquidity shortages, market fluctuations, fragmentation, security breaches and outright fraud associated with alternative crypto-currencies.

The acquisition of GreenAddress is part of the move by the company to begin acquiring companies in the bitcoin and blockchain technology space to increase the reach of their platform and allow them to meet the requirements of their enterprise applications.

It’s not clear whether GreenAddress had received venture backing before being acquired but Blockstream itself can certainly afford more acquisitions going forward given it has so far raised $76 million over two rounds from investors including AXA Strategic Ventures, Digital Garage, Horizons Ventures, Khosla Ventures, and Real Ventures.

Image credit: GreenAddress.