Blockchain patent filings indicate that IBM, Walmart and Alibaba are currently the most active in R&D

Patents are a way for companies or individuals to legally protect intellectual property while sharing these ideas with the public. The blockchain space—ideologically rooted in open source—has traditionally been skeptical of companies that patent novel blockchain developments. The vast majority of projects in the ecosystem is developed as open source, which means anyone can review the code, propose modifications, or even fork the project (remixing it to a new development). 

Patenting blockchain ideas still occurs fairly frequently though nearly all patents are applied for by traditional non-blockchain companies. According to The Block’s research, there are now more than 1,000 pending patent applications. Half of the pending patents have been filed by only seven companies — IBM (143), nChain (112), Walmart (54), Intel (54), Alibaba (49), Mastercard (48), and Bank of America (46).