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. 24, 2026
Filed:
Jun. 26, 2024
GM Global Technology Operations Llc, Detroit, MI (US);
Mohamed A. Layouni, Fraser, MI (US);
Brian Farrell, Troy, MI (US);
Christopher J. Kloote, Livonia, MI (US);
Manohar Reddy Nanjundappa, Cedar Park, TX (US);
Kenneth Junk, Marshalltown, IA (US);
GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US);
Abstract
Methods for updating 256-bit cryptographic keys by a cryptographic key update system include transmitting a first transmission, a second transmission, and a third transmission. The second transmission is a symmetric key encryption under a key encryption key of a concatenation of a plurality of parameters and a new cryptographic key. The sender derives the key encryption key by transforming an authentication key and a bit string of constant values based on a one-way compression function that is one of the following: a modification detection code 2 (MDC-2) cryptographic hash function with a 128-bit advanced encryption standard (AES-128) as the underlying block cipher, a modification detection code 4 (MDC-4) cryptographic hash function with the 128-bit advanced encryption standard (AES-128) as the underlying block cipher, the Hirose compression function with the 256-bit advanced encryption standard (AES-256) as the underlying block cipher, and a 256-bit hash function.