The application for the patent was submitted in August of 2016 but was just published last week on February 15th.
SOURCE
The patent is for a system to “verify integrity of physical documents,” using a "security Blockchain.”
The patent's summary explains that an "integrity symbol" will be identified within a document, that is then converted into an "integrity map" and then compare this map to the physical document to ensure the document's integrity.
The use of digital signatures encoded into documents provides assurance that the document(s) were not modified after signing, as compared to physical ones.
READ MORE AT: https://cointelegraph.com/news/lenovo-explores-blockchain-for-document-validation-with-us-patent