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:
Aug. 20, 2024
Filed:
Dec. 08, 2021
Microsoft Technology Licensing, Llc, Redmond, WA (US);
Stefan Saroiu, Redmond, WA (US);
Varun Gandhi, Boston, MA (US);
Alastair Wolman, Seattle, WA (US);
Landon Prentice Cox, Seattle, WA (US);
MICROSOFT TECHNOLOGY LICENSING, LLC, Redmond, WA (US);
Abstract
A health ticket minting process operates in a secure enclave on a computing device to ensure liveness of the enclave should a maliciously-compromised operating system deny service to starve the enclave. Cryptographically-secured health tickets provided by the minting process reset an authenticated watchdog timer (AWDT) that reboots the device from a hardware-protected recovery operating system if the timer expires. The health tickets are written to a secure channel using a symmetric key that is provisioned by repurposing an existing Intel SGX (Software Guard Extension) Versioning Support protocol that enables migration of secrets between enclaves that have the same author. In the event that the enclave fails to make forward progress and health tickets are not minted, then the AWDT expires and forces the reboot and re-imaging to a known good state to evict the malware from the computing device.