Privacy and Security for Resource-Constrained IoT Devices and Networks: Research Challenges and Opportunities

Leveraging Larger AES Keys in LoRaWAN: A Practical Evaluation of Energy and Time Costs

Internet of Things (IoT) devices increasingly contribute to critical infrastructures, necessitating robust security measures. LoRaWAN, a low-power IoT network, employs the Advanced Encryption Standard (AES) with a 128-bit key for encryption and integrity, balancing efficiency and security. As computational capabilities of devices advance and recommendations for stronger encryption, such as AES-256, emerge, the implications of using longer AES keys (192 and 256 bits) on LoRaWAN devices' energy consumption and processing time become crucial. Despite the significance of the topic, there is a lack of research on the implications of using larger AES keys in real-world LoRaWAN settings. To address this gap, we perform extensive tests in a real-world LoRaWAN environment, modifying the source code of both a LoRaWAN end device and open-source server stack to incorporate larger AES keys. Our results show that, while larger AES keys increase both energy consumption and processing time, these increments are minimal compared to the time on air. Specifically, for the maximum payload size we used, when comparing AES-256 to AES-128, the additional computational time and energy are, respectively, 750 ms and 236 μJ. However, in terms of time on air costs, these increases represent just 0.2% and 0.13%, respectively. Our observations confirm our intuition that the increased costs correlate to the number of rounds of AES computation. Moreover, we formulate a mathematical model to predict the impact of longer AES keys on processing time, which further supports our empirical findings. These results suggest that implementing longer AES keys in LoRaWAN is a practical solution enhancing its security strength while not significantly impacting energy consumption or processing time.

Evaluation of Correlation between Temperature of IoT Microcontroller Devices and Blockchain Energy Consumption in Wireless Sensor Networks

Blockchain technology is an information security solution that operates on a distributed ledger system. Blockchain technology has considerable potential for securing Internet of Things (IoT) low-powered devices. However, the integration of IoT and blockchain technologies raises a number of research issues. One of the most important is the energy consumption of different blockchain algorithms. Because IoT devices are typically low-powered battery-powered devices, the energy consumption of any blockchain node must be kept low. IoT end nodes are typically low-powered devices expected to survive for extended periods without battery replacement. Energy consumption of blockchain algorithms is an important consideration in any application that combines both technologies, as some blockchain algorithms are infeasible because they consume large amounts of energy, causing the IoT device to reach high temperatures and potentially damaging the hardware; they are also a possible fire hazard. In this paper, we examine the temperatures reached in devices used to process blockchain algorithms, and the energy consumption of three commonly used blockchain algorithms running on low-powered microcontrollers communicating in a wireless sensor network. We found temperatures of IoT devices and energy consumption were highly correlated with the temperatures reached. The results indicate that device temperatures reached 80 °C. This work will contribute to developing energy-efficient blockchain-based IoT sensor networks.

Lightweight Digital Certificate Management and Efficacious Symmetric Cryptographic Mechanism over Industrial Internet of Things

The certificate authority, a trusted entity, issues digital certificates which contain identity credentials to help Industrial Internet of Things (IIoT) devices to represent their authenticity in a secure means. The crucial challenge of a digital certificate is to how design a secure certification authority management system that can counteract cyberattacks on the IIoT network. Moreover, current IIoT systems are not capable of implementing complex mathematical operations due to their constrained power capacity and processing capability. This paper proposes an effective, secure symmetric cryptographic mechanism (ESSC) based on the certificate authority management and Elliptic Curve Diffie Hellman (ECDH) to share a digital certificate among IIoT devices. The proposed certificate authority is used to securely exchange the shared secret key and to resolve the problem of spoofing attacks that may be used to impersonate the identity of the certificate authority. Also, ESSC uses the shared secret key to encrypt the sensitive data during transmission through the insecure communication channel. This research studies the adversary model for ESSC on IIoT and analyzes the cybersecurity of ESSC in the random oracle model. The findings that result from the experiments show that ESSC outperforms the baseline in terms of communication, computation, and storage costs. ESSC thus provides an adequate lightweight digital certificate management and cryptographic scheme which can help in the detection and prevention of several cyberattacks that can harm IIoT networks.