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:
Feb. 15, 2011
Filed:
Sep. 18, 2006
Andrew Dellow, Gloucestershire, GB;
Peter Bennett, Bristol, GB;
Rodrigo Cordero, Bristol, GB;
STMicroelectronics Limited, Bristol, GB;
Abstract
A memory stores data in an encrypted form. A modifiable register stores a memory address, a, defining a boundary separating the memory into two regions. The lower region stores data encrypted using a key B, and the upper region stores data encrypted using a different key A. Data stored on the boundary address is encrypted using key A. Accordingly, when data is read from a memory address a, key A is used to decrypt the data if a≧a, and key B is used if a<a. However, when data is written to a memory address a, then key A is used to encrypt the data if a≧a+1, key B is used if a<a+1. When data is written to the boundary address, a, the position of the boundary is caused to increase by one unit.