Patent · US Active

Key expansion logic using decryption key primitives

US9967092B2 · kind B2 · utility

7Cited by

34References

21Claims

0Family size

Assignee

VIA Technologies, Inc. · TW

Inventors

G. Glenn Henry · Austin, US
Terry Parks · Austin, US
Brent Bean · Austin, US
Thomas A. Crispin · Austin, US

Key dates

Filing date	Oct 15, 2015
Grant date	May 8, 2018
Priority date	—
Expiry date	Oct 15, 2035

Classification

Technology area (CPC H)Electricity
CPC primaryH04L2209/20
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

A secure memory, key expansion logic, and decryption logic are provided for a microprocessor that executes encrypted instructions. The secure memory stores a plurality of decryption key primitives. The key expansion logic selects two or more decryption key primitives from the secure memory and then derives a decryption key from them. The decryption logic uses the decryption key to decrypt an encrypted instruction fetched from the instruction cache. The decryption key primitives are selected on the basis of an encrypted instruction address, one of them is rotated by an amount also determined by the encrypted instruction address, and then they are additively or subtractively accumulated, also on the basis of the encrypted instruction address.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.