ALEXANDRIA, Va., June 16 -- United States Patent no. 12,307,546, issued on May 20, was assigned to Equity Shift Inc. (Raleigh, N.C.).

"Anti-leak digital document marking using distributed ledger to generate a code uniquely corresponding to a unique value for each digital document" was invented by Thomas Marshall Gordon III (Raleigh, N.C.) and Gregory Frederick Bush (Cary, N.C.).

According to the abstract* released by the U.S. Patent & Trademark Office: "The system is disclosed for visual marking sensitive documents for leak prevention. Each time an action is taken with regard to a document (e.g., creation, viewing, downloading), that action is added to a distributed ledger, essentially creating a unique hash for a new instance of the docu...