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. 14, 2023
Filed:
Dec. 11, 2020
Applicant:
Cryptography Research, Inc, San Jose, CA (US);
Inventors:
Ambuj Kumar, Sunnyvale, CA (US);
Ronald Perez, Piedmont, CA (US);
Assignee:
Rambus Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04L 9/00 (2022.01); H04L 9/08 (2006.01); G09C 1/00 (2006.01);
U.S. Cl.
CPC ...
H04L 9/0861 (2013.01); G09C 1/00 (2013.01); H04L 9/085 (2013.01); H04L 9/0891 (2013.01);
Abstract
A secret key value that is inaccessible to software is scrambled according to registers consisting of one-time programmable (OTP) bits. A first OTP register is used to change the scrambling of the secret key value whenever a lifecycle event occurs. A second OTP register is used to undo the change in the scrambling of the secret key. A third OTP register is used to affect a permanent change to the scrambling of the secret key. The scrambled values of the secret key (whether changed or unchanged) are used as seeds to produce keys for cryptographic operations by a device.