NFC Tag Configures Ultra Low Power Bluetooth Encryption Keys
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultra low power wireless devices, such as energy harvesting sensors, face challenges in secure communication due to limited power budgets, making it difficult to receive configuration data and maintain secure encryption keys, which can lead to insecure data transmission and impersonation risks.
Innovation Solution
The use of Near Field Communications (NFC) to configure and share encryption keys between an ultra low power network device and a configuration tool, enabling secure key creation and periodic refreshment without the need for power-intensive data reception, using elliptic curve Diffie-Hellman key exchange and NFC tags for energy-efficient communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ultra low power device receives BLUETOOTH® communications to obtain configuration data and encryption keys, then secure communication is enabled, but power consumption increases significantly
Solution Approach 1:
The patent introduces NFC as an intermediary communication mechanism for key exchange. The NFC tag stores configuration data and encryption keys that are transferred to the ultra low power device through NFC communication, which consumes minimal power compared to BLUETOOTH® reception. This intermediary approach allows the device to obtain secure communication credentials without activating power-intensive BLUETOOTH® receive circuitry.
Solution Approach 2:
The patent implements preliminary configuration where encryption keys and configuration data are pre-loaded into the NFC tag before the ultra low power device operates. This preliminary action enables the device to acquire all necessary security credentials during initial NFC-based setup, eliminating the need for subsequent power-consuming BLUETOOTH® communication sessions for key acquisition.
2Use of energy by moving object
If the device uses pre-configured encryption keys to conserve energy, then power consumption is reduced, but security is compromised due to potential key compromise
Solution Approach 1:
The patent implements periodic refreshment of encryption keys using NFC communication. At predetermined intervals, the ultra low power device wakes up to perform NFC communication with a configuration tool to receive refreshed encryption keys. This periodic action maintains security by regularly updating keys while consuming minimal power, as the device remains in sleep mode between refresh cycles and only activates NFC (not full BLUETOOTH® reception) for key updates.
3Use of energy by moving object
If the device eliminates receive circuitry to save power, then power consumption is minimized, but configuration and key management become impossible
Solution Approach 1:
The NFC tag serves as an intermediary that carries configuration data and encryption keys to the ultra low power device during initial setup and periodic refreshes. This intermediary mechanism enables configuration and key management without requiring the device to have active BLUETOOTH® receive circuitry, as all configuration exchanges occur through the low-power NFC interface.
Data Source
AI summary
An ultra low power network device is disclosed. The network device utilizes a Near Field Communications (NFC) tag to enable ultra low power communications with a configuration tool. The configuration tool writes information to the NFC tag that is accessible by the processing unit on the ultra low power network device. Additionally, the processing unit can write information into the NFC tag that is readable by the configuration tool. By exchanging messaged in this manner, the ultra low power network device and the configuration tool may create a shared encryption key. The ultra low power network device utilizes this shared encryption key when transmitting BLUETOOTH® packets. The configuration tool may then transmit the shared encryption key to either another BLUETOOTH® device or to a remote server. The ultra low power network device may also periodically refresh the shared encryption key.