The U.S. Patent and Trademark Office has released nine more blockchain-related patent applications filed by Bank of America.

Data collected by CoinDesk shows that the applications – which relate to conducting and settling transactions within a payment network – were all filed February 22. To date, Bank of America has filed more than 30 known patent applications related to the technology, including as many as 18 during 2016 alone.

Combined, the breadth of the applications suggests that work is being done on blockchain-based payment systems within Bank of America. At the same time, the bank has issued no definitive statements on the subject to date, and it's not clear whether any of the proposed inventions will see the light of day.

Yet past announcements from the bank hint at where some of the intellectual property may come into play.

Last September, Bank of America and Microsoft announced a joint initiative aimed at applying blockchain tech to the area of trade finance. Working with Microsoft Treasury, which handles the tech giant's corporate payments and strategic investments, the project is aimed at building a new blockchain-based system to facilitate transactions between the two companies.

Still, it remains to be seen whether the project turns into something at commercial scale. And given the pace of patent applications seen thus far during 2016, Bank of America could be pursuing other intellectual property avenues as well.

Bank of America image via Roman Tiraspolsky/Shutterstock