US 12395359

An analysis of United States Patent 12,395,359 reveals the following details. A search of the United States Court of Appeals for the Federal Circuit (CAFC) dockets for 2026 found no public record of this patent.

Summary of U.S. Patent 12,395,359

Title: Method of implementing a physical unclonable function

Assignee: Thales DIS France SA. The assignment history also includes Thales DIS Design Services SAS.

Inventors:

• Benjamin Duval
• Alexandre Berzati
• Olivier Fourquin

Filing Date: September 17, 2021

Issue Date: August 19, 2025

Abstract: The patent describes a method and an electronic device for repairing the output of a Physical Unclonable Function (PUF). A PUF generates a unique digital response from the physical characteristics of a device. The invention provides a way to detect errors in this response, identify the specific faulty bits, and replace them with pre-selected, reliable "additional output bits." The process involves creating and storing a "repair list" that maps the erroneous bits to their replacements, ensuring the PUF's response remains correct and stable over time.

Plain-Language Overview of Independent Claims

The patent includes four independent claims which define the core of the invention.

Independent Claim 1: This claim outlines a method for repairing the digital "fingerprint" (response) from a PUF. The steps are:

1. Generate the PUF's response.
2. Detect if there is an error in the response.
3. Pinpoint the exact incorrect bit(s) by systematically replacing each bit in the response, one by one in a random order, with a test value until the error is corrected.
4. Find a reliable, spare "additional output bit" that can serve as a permanent replacement.
5. Store the location of the bad bit and its corresponding good replacement bit in a "repair list."
6. Finally, replace the erroneous bit in the PUF's response with the good bit from the repair list.

Independent Claim 6: This claim describes a method almost identical to the one in Claim 1, with one key difference. When determining which response bits are erroneous (step 3), the one-by-one replacement of each bit is done in a predetermined order, rather than a random one.

Independent Claim 12: This claim describes the physical electronic device that performs the method detailed in Claim 1. The device is equipped with the necessary components, including:

• Active electronic primitives (the basis for the PUF).
• PUF circuits to generate the response.
• A processor and memory.
  The device is configured to execute all the steps of the repair method, including the search for erroneous bits in a random order.

Independent Claim 14: This claim also describes an electronic device, but one that is configured to perform the method outlined in Claim 6. It comprises the same types of hardware as the device in Claim 12. The distinguishing feature is that this device is configured to identify the faulty PUF bits by replacing them one-by-one in a predetermined order.