US 12,393,702 B2
Protecting cryptographic keys stored in non-volatile memory
Mark Evan Marson, Carlsbad, CA (US); and Michael A. Hamburg, Laguna Beach, CA (US)
Assigned to CRYPTOGRAPHY RESEARCH, INC., San Jose, CA (US)
Filed by CRYPTOGRAPHY RESEARCH, INC., San Jose, CA (US)
Filed on Jun. 30, 2022, as Appl. No. 17/854,295.
Application 17/854,295 is a continuation of application No. 16/963,724, granted, now 11,416,625, previously published as PCT/US2019/015765, filed on Jan. 30, 2019.
Claims priority of provisional application 62/679,317, filed on Jun. 1, 2018.
Claims priority of provisional application 62/624,694, filed on Jan. 31, 2018.
Prior Publication US 2022/0405404 A1, Dec. 22, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 21/60 (2013.01); G06F 1/24 (2006.01); G06F 12/14 (2006.01); G06F 21/79 (2013.01); H04L 9/08 (2006.01)
CPC G06F 21/602 (2013.01) [G06F 1/24 (2013.01); G06F 12/1408 (2013.01); G06F 21/79 (2013.01); H04L 9/0822 (2013.01); H04L 9/0894 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
storing a volatile key in a volatile memory;
storing a masked cryptographic key in a non-volatile memory, wherein the masked cryptographic key is produced by combining a cryptographic key and a device root key; and
storing a masked device root key in the non-volatile memory, wherein the masked device root key is produced by combining the device root key and the volatile key.