Lightweight and post-quantum safe security solutions for IoT systems
Creators: name: Khan, Muhammad Nauman
Publisher: name: RMIT University
Year: 2024
Subjects: classificationCode: 460403
subject: Data security and protection

description: The recent emergence and expansion of the Internet of Things (IoT) and its applications have dramatically changed the IT services supporting domains such as manufacturing, energy management, intelligent transportation, smart cities and defence. These IT services interconnect Internet-based cloud systems with IoT or smart devices, such as cars, fridges, light bulbs, TVs and home security devices, to transform the physical world into the cyber world. As a result, IoT has applications in a broad spectrum of areas such as smart homes, smart cities, healthcare, water and sanitation, transportation, defence, environment and agriculture.

The integration of IoT with emerging technologies, such as Edge, Fog, and Cloud computing, opens up endless opportunities and benefits for its users but also poses numerous security challenges. These security challenges are mainly due to the resource-constrained nature of IoT devices. Several computationally lightweight cryptographic protocols exist for these resource-constrained IoT devices. However, due to the asymmetric computational nature of end-to-end IoT-based systems with resource-limited and resource-rich devices, lightweight cryptographic protocols could become security soft-spots and cause
critical vulnerabilities over resource-rich devices like Edge, Fog or Cloud computing. These vulnerabilities are due to the availability of computational resources at these platforms (Edge, Fog and Cloud) for multi-tenancy/-programming and their operations in relatively more malicious environments.

This research is motivated by the lack of cryptographic schemes that take into account the asymmetric and heterogeneous nature of IoT systems. Most cryptographic protocols do not address the asymmetric computational nature of devices across IoT-based systems. The resource-rich components (e.g., Edge, Fog and Cloud), possibly operating in highly contaminated environments (e.g., Internet), need stronger security protocols than their resource-limited counterparts in an IoT-based system. With the addition of vulnerabilities due to evolving quantum computing (i.e., cryptographic primitives that can be broken by quantum computers), the attack surface of the IoT-based systems also increases. Hence, there is a need for asymmetric cryptographic protocols that can adapt to the asymmetric computational nature of devices across IoT architecture and protect
against quantum attacks.

We are interested in both theoretical and technical aspects of the asymmetric computational nature of devices across IoT. We begin with critically analyzing the resource constraints of the range of devices at Cloud, Fog, Edge and smart nodes and the feasibility of existing lightweight cryptographic protocols on these devices. First, we conduct a comparative analysis and classify the existing lightweight cryptographic protocols against security requirements, including confidentiality, privacy, authentication, access control, resource asymmetry, etc. After analyzing these cryptographic protocols, we identify that the major portion of the literature is related to IoT communication protocols, authentication, vulnerability and attacks on IoT systems, while a few recent works partially address the asymmetric capabilities of devices in IoT systems. Second, we highlight the need for a cryptographic protocol with elasticity that can adapt to the asymmetric capabilities of different devices across the IoT structure.

The development of elastic cryptographic protocols that can adapt according to the resources of the devices in IoT systems is a crucial task. One way to achieve this is by taking advantage of the resourceful parties involved in the communication to perform
computations on ciphertext without leaking any information or compromising the privacy of the communicating parties. Proxy re-encryption schemes are widely used to outsource ciphertext to edge nodes (proxy) and can perform computations on that
outsourced data. We propose a proxy re-encryption scheme that transforms the ciphertext to make it suitable and secure on smart and resource-rich devices. For this, we design an efficient ABE-IBE proxy re-encryption scheme that converts the ciphertext encrypted under ABE with classical encryption to IBE with post-quantum safe encryption and then converts ciphertext re-encrypted under IBE with post-quantum safe encryption to IBE with classical encryption. In this proposed scheme, we use bilinear pairing (classical cryptography) for ABE and IBE schemes at sender and receiver ends, while re-encryption and re-decryption use lattice-based cryptography (post-quantum safe) at proxy (fog/edge) nodes. We conduct the experimental and security analysis of our proposed proxy re-encryption scheme and compare the results with the existing classical ABE-IBE proxy re-encryption scheme.

Post-Quantum construction of various algorithms is an interesting field of research. We use the post-quantum safe learning with error (LWE) problem from lattice-based cryptography to improve the results of our proposed ABE-IBE proxy re-encryption scheme. In this part of our research, we explicitly demonstrate the structures of post-quantum secure ABE and IBE schemes (using lattice-based LWE) to design the first-of-its-kind Post-Quantum secure ABE-IBE proxy encryption scheme without using the classical encryption schemes. This lattice-based proxy re-encryption scheme improves the security of proxy nodes and smart end devices (sender and receiver) from quantum adversaries.