Secure Non-Volatile Logging in Active RFID Tags
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing active RFID tags lack secure non-volatile logging capabilities, particularly for longer observation periods, and are vulnerable to unauthorized data access and modification due to unrestricted access to the non-volatile memory at 13.56 MHz frequency band.
Innovation Solution
The method initializes the RFID tag to prevent writing in the logging area by setting lock flags, allowing only secure logging of essential data characterizing the process in the tagged article, using a password-protected system to safeguard the memory areas and reducing data volume by converting acquired values into less numerous data within specified limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the sampling period is extended to cover longer observation periods (e.g., ship transport), then the logging duration is improved, but important process events may be missed due to insufficient sampling frequency
Solution Approach 1:
The patent implements dynamic sampling where the sampling period adapts based on process conditions. The system uses multiple sampling rates (e.g., 10 minutes for normal conditions, 1 second for critical events) and automatically adjusts the sampling frequency based on whether critical thresholds are exceeded, thus resolving the contradiction between long logging duration and accurate event detection
Solution Approach 2:
The patent combines multiple sampling strategies into a unified logging system that operates at different time scales simultaneously. It merges long-term monitoring (extended logging duration) with short-term critical event detection (high sampling frequency when needed) into a single adaptable system that covers both requirements
2Ease of operation
If access to the non-volatile memory is unrestricted to allow any interrogator to read and write data, then the ease of operation is improved, but the security against unauthorized access and data falsification deteriorates
Solution Approach 1:
The patent applies different access rights to different memory areas. The logging area has restricted write access (only during initialization and automatic logging) while other memory areas may have different permissions. This local differentiation of access quality allows easy reading operation while securing critical logging data against unauthorized modification
Solution Approach 2:
The patent implements preliminary security measures by setting lock flags and password protection during initialization before any data logging occurs. This preliminary action ensures that once logging starts, the data is protected against falsification, maintaining both security and operational ease for authorized users
3Loss of information
If all acquired sensor values are logged in detail, then the completeness of process information is improved, but the memory capacity is exhausted too quickly, limiting the logging period
Solution Approach 1:
The patent extracts and logs only the most critical process information rather than all raw sensor data. It identifies key parameters and critical threshold exceedances to log, removing unnecessary detailed data while preserving essential process information, thus extending the logging period within limited memory capacity
Solution Approach 2:
The patent changes the parameter representation by logging processed information (e.g., threshold exceedance events, critical parameter changes) rather than raw continuous sensor values. This parameter transformation reduces data volume while maintaining the ability to reconstruct important process characteristics
Data Source
AI summary
Prior to logging of a process flags for locking at all addresses of a logging area of a tag are set to state 1 by means of an interrogator. A high limit (h) and a low limit (l) of an interval (l-h) of such values (v) of a physical parameter are determined, which are proper for preserving usability of a tagged article. Said values (v) acquired with a sensor and acquisition times related thereto are converted into less numerous data characterizing the process by observing said limits (h, l). Said data characterizing the process are logged in said logging area. Said process log cannot be modified in any way at a later stage. The invention also provides for an efficient observation of longer period of the process in the tagged article in order to inspect the usability thereof.