Frame Counter Memory Layout for Low-Energy Replay Protection

Solution Overview

Problem

Energy limited devices face challenges in maintaining frame counter mechanisms due to the high energy consumption and time requirements of traditional Flash memory storage, making it difficult to implement secure frame counting and prevent unauthorized signal retransmission by hackers.

Innovation Solution

A method and device for recording a frame counter in an energy limited device using a memory component that allocates space based on a predetermined maximum frame counter number, converting empty space indicia to frame counter indicia without erasing, and accessing bit positions efficiently to maintain frame freshness checking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional Flash memory is used to store frame counter, then secure frame counting can be implemented, but energy consumption increases and update time increases

Engineering Contradiction:

Improveframe counter securityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent divides the frame counter storage into two separate memory components: a first memory component for storing the current frame counter value and a second memory component for storing the previous frame counter value. This segmentation allows the system to implement secure frame counting by comparing current and previous values without requiring expensive erase operations in traditional Flash memory, thereby reducing energy consumption while maintaining security against replay attacks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the storage parameter from traditional Flash memory to a different memory component that supports faster write operations without erase requirements. This parameter change enables the system to achieve both security (through frame counter comparison) and low energy consumption (by avoiding erase operations), directly resolving the technical contradiction.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If traditional Flash memory is used to store frame counter, then secure frame counting can be implemented, but update speed decreases

Engineering Contradiction:

Improveframe counter securityVSAvoidupdate speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent divides the frame counter storage into two separate memory components: a first memory component for storing the current frame counter value and a second memory component for storing the previous frame counter value. This segmentation allows the system to implement secure frame counting by comparing current and previous values without requiring expensive erase operations in traditional Flash memory, thereby reducing energy consumption while maintaining security against replay attacks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the storage parameter from traditional Flash memory to a different memory component that supports faster write operations without erase requirements. This parameter change enables the system to achieve both security (through frame counter comparison) and low energy consumption (by avoiding erase operations), directly resolving the technical contradiction.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If frame counter is not recorded, then energy consumption is low, but security against hacked signal retransmission is lost

Engineering Contradiction:

Improveenergy consumptionVSAvoidsignal security

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements preliminary action by storing the previous frame counter value in advance in a second memory component before the current frame counter is updated. This allows the system to perform security verification by comparing the current frame counter with the previously stored value, preventing hacked signal retransmission while maintaining low energy consumption through efficient memory operations that avoid expensive erase cycles.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a second memory component as an intermediary to store the previous frame counter value. This intermediary enables security verification without requiring expensive erase operations in traditional Flash memory, allowing the system to achieve both low energy consumption and high signal security through efficient comparison operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20260037314A1Frame counter recordal and an energy limited device

Publication Date: 2026.02.05 SCHNEIDER ELECTRIC ASIA PTE LTD

AI summary

A method of recording a frame counter in a memory component of an energy limited device and an energy limited device are provided, the method comprising, accessing the memory component; wherein for a first recordal, allocating a memory space of the memory component based on a value of a predetermined maximum frame counter number for the energy limited device, with each bit of the allocated memory space being populated with an empty space indicia; and wherein for the first recordal and each subsequent recordal, accessing a first bit position with the empty space indicia based on a predetermined writing instruction and converting the empty space indicia of the first bit position to a frame counter indicia wherein the first bit position with the frame counter indicia indicates a current frame counter number.