The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 2018
Filed:
Mar. 16, 2016
Konica Minolta Laboratory U.s.a., Inc., San Mateo, CA (US);
Kyohei Shiraishi, San Mateo, CA (US);
Rabindra Pathak, San Jose, CA (US);
KONICA MINOLTA LABORATORY U.S.A., INC., San Mateo, CA (US);
Abstract
In a digital rights management system, layers are defined for each document and user permissions are specified for each layer, to control user access at the layer-level. The layers are ordered by depth, where a layer completely contained inside another layer is deemed deeper than the other layer. The layers are encrypted in a deep-to-shallow order, each by its own encryption key. The entire document is then encrypted. When a user requests access to a document, the system generates an ordered sequence of encryption keys based on the user's access rights for each layer. The document open program on the user's client computer attempts to decrypt the various layers using the ordered sequence of keys. The client program and the system's key sequence generating algorithm are designed to give the result that only layers that the user has access to are successfully decrypted and displayed at document open time.