Hi! In the light of the recent PayPal patent, I had been doing some patent fulltext search on blockchain. And I did find something. Unfortunately, I am not really able to conclude on the significance of these patents given the law jargon used. However, some of you would probably be interested to look into it:

Winklevoss+AND+%40PD>%3D20180101<%3D20180307)&OS=ACLM/blockcha$+AND+ISD/1/1/2018->3/7/2018&RS=(ACLM/blockcha$+AND+ISD/20180101->20180307))

Bank of America+AND+%40PD>%3D20180101<%3D20180307)&OS=ACLM/ledger$+AND+ISD/1/1/2018->3/7/2018&RS=(ACLM/ledger$+AND+ISD/20180101->20180307))

MasterCard&OS=ABST/blockch$+AND+ISD/1/1/2018->3/7/2018&RS=(ABST/blockch$+AND+ISD/20180101->20180307))