Blockstream has officially announced $21m in seed funding to continue the development of its much-anticipated blockchain technology proposal, 'sidechains'.

Announced on the Blockstream website, the round was led by LinkedIn co-founder and Airbnb board member Reid Hoffman; Khosla Ventures, which has previously invested in bitcoin API developer Chain; and Canada-based seed fund Real Ventures. In total, Blockstream indicated 40 investors took part in the round.

Blockstream CEO Austin Hill positioned the funding as proof that the wider tech industry is increasingly acknowledging the disruptive potential of the technological innovations first introduced by bitcoin through its underlying ledger.

Hill wrote:

First introduced earlier this year and released on 23rd October, the sidechains white paper seeks to enable the creation of an entire ecosystem of blockchains over which digital assets can be exchanged and transferred, with bitcoin serving as the lead chain for such activity.

Additional investment firms that contributed to the round included Crypto Currency Partners, Google chairman Eric Schmidt’s Innovation Endeavors, Future\Perfect Ventures, Mosaic Ventures, Ribbit Capital and Yahoo co-founder Jerry Yang’s AME Cloud Ventures.

The announcement comes roughly one month after the first news regarding Blockstream’s funding round leaked online via an October filing with the US Securities and Exchange Commission. At the time, the document revealed Blockstream had raised $15m in funding, and that Hoffman would serve on the company’s board of directors.

Hoffman, in turn, took to LinkedIn today to discuss his investment, penning a lengthy entry on his belief in bitcoin as a revolutionary technology that will enable innovations in commerce.

Images via Blockstream; Shutterstock