ResearchSpace :: Browsing by Author "Ledwaba, Lehlogonolo PI"

Browsing by Author "Ledwaba, Lehlogonolo PI"

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A delegated proof of proximity scheme for industrial internet of things consensus
(2020-10) Ledwaba, Lehlogonolo PI; Hancke, GP; Mitrokotsa, A; Isaac, Sherrin J
Recently, work with Distributed Ledger Technologies (DLTs) has focussed on leveraging the decentralised, immutable ledger for use outside of cryptocurrency. One industry poised to benefit from DLTs is the Industrial Internet of Things (IIoT); as the inherent cryptographic mechanisms and alternative trust model make DLTs an attractive solution for distributed networks. Existing DLTs are unsuitable for the IIoT, owing to the large computational and energy requirements for consensus operations and the slow throughput of validated blocks. With limited processing, energy and storage resources and a deadline sensitive operational environment, DLTs in their current state could serve to introduce intolerable latency into IIoT processes and deplete constrained, device resources. Designed for the IIoT context, and based off Delegated Proof of Stake, this work serves to introduce a new consensus mechanism called Delegated Proof of Proximity (DPoP). Using existing location discovery processes, nodes in close proximity to a sensor event are elected as delegates; whose role is to handle consensus and block generation. In using information already known to IIoT devices, DPoP aims to reduce wasted effort, improve throughput by limiting the number of nodes required for consensus operations and improve scalability and flexibility of DLT solutions as the IIoT network continues to grow.
Developing a secure, smart microgrid energy market using distributed ledger technologies
(IEEE, 2019-07) Ledwaba, Lehlogonolo PI; Hancke, GP; Isaac, Sherrin J; Venter, HS
The ability for the smart microgrid to allow for the independent generation and distribution of electrical energy makes it an attractive solution towards enabling universal access to electricity within developing economies. Distributed Ledger Technologies (DLTs) are being considered as an enabling technology for the secure energy trade market however the high processing, energy and data exchange requirements may make them unsuitable for the Industrial Internet of Things technologies used in the implementation of the microgrid and the limited connectivity infrastructure in developing technologies. This work serves to assess the suitability of DLTs for IIoT edge node operation and as a solution for the microgrid energy market by considering node transaction times, operating temperature, power consumption, processor and memory usage, in addition to mining effort and end user costs.
Evaluating trust models for the IoT-enabled peer to-peer energy market
(2025-07) Leotlela, B; Ledwaba, Lehlogonolo PI; Coetzee, M
The decentralised nature of peer-to-peer (P2P) energy markets creates an environment where trust is difficult to establish. Supported by Internet of Things (IoT) devices, trust and security challenges arise, due to the absence of central oversight and the risk of uncooperative participant behaviour. A comparative analysis of existing trust management models and schemes is conducted in this study comparing how they are designed to encourage cooperation and ensure reliable interactions in decentralized energy markets. Emphasis is placed on how these models integrate security mechanisms to build trust and on their computational efficiency for IoT constrained environments. The analysis highlights the trade offs between trust management and IoT device performance, identifying limitations in scalability and latency as participation scales. Results indicate that while several models effectively build trust and promote cooperation, many impose significant resource demands, underscoring the need for balance between trust assurance and operational efficiency. This work provides a comprehensive evaluation of trust mechanisms in transactive energy systems and offers insights into their practical viability in resource-constrained, decentralized environments.
Investigating distance bounding for delegated proof-of-proximity consensus within IIoT
(2022-06) Ledwaba, Lehlogonolo PI; Hancke, GP; Isaac, Sherrin J
With limited processing, energy and storage along with a deadline sensitive operational environment, the combination of the Industrial IoT (IIoT) with distributed ledger technologies (DLTs) could serve to introduce intolerable latency into network processes; counteracting the potential advantages that come from combining the two technologies. In an effort to improve the compatibility of DLTs for the industrial informatics context, the authors developed a lightweight consensus for IIoT environments based off delegated proof of stake (DPoS), called Delegated Proof of Proximity (DPoP), to limit the processing and energy effort required by DLTs. DPoP will, however, require an existing, IIoT neighbour discovery process to facilitate a proof of proximity for the consensus process. Thus, this preliminary work aims to evaluate distance bounding as a possible mechanism for establishing a secure proof of proximity and neighbour discovery between nodes during the DPoP consensus process to improve the scalability and flexibility of DLT solutions, like Ethereum, for IIoT use cases.
Open hardware: a role to play in wireless sensor networks?
(MDPI, 2015-03) Fisher, R; Ledwaba, Lehlogonolo PI; Hancke, GP; Kruger, Carel P
The concept of the Internet of Things is rapidly becoming a reality, with many applications being deployed within industrial and consumer sectors. At the ‘thing’ level—devices and inter-device network communication—the core technical building blocks are generally the same as those found in wireless sensor network implementations. For the Internet of Things to continue growing, we need more plentiful resources for building intelligent devices and sensor networks. Unfortunately, current commercial devices, e.g., sensor nodes and network gateways, tend to be expensive and proprietary, which presents a barrier to entry and arguably slows down further development. There are, however, an increasing number of open embedded platforms available and also a wide selection of off-the-shelf components that can quickly and easily be built into device and network gateway solutions. The question is whether these solutions measure up to built-for-purpose devices. In the paper, we provide a comparison of existing built-for-purpose devices against open source devices. For comparison, we have also designed and rapidly prototyped a sensor node based on off-the-shelf components. We show that these devices compare favorably to built-for-purpose devices in terms of performance, power and cost. Using open platforms and off-the-shelf components would allow more developers to build intelligent devices and sensor networks, which could result in a better overall development ecosystem, lower barriers to entry and rapid growth in the number of IoT applications.
Performance costs of cryptography in securing new-generation Internet of Energy endpoint devices
(IEEE, 2018-01) Ledwaba, Lehlogonolo PI; Hancke, GP; Venter, HS; Isaac, Sherrin J
In past years, cryptography has been considered a difficult task to achieve on sensor nodes for the Internet of Energy (IoE) owing to the resource-constrained nature of 8-bit and 16-bit microcontroller units (MCUs). Previous attempts at implementing cryptographic services on wireless sensor nodes have resulted in high power consumptions, long operating times and the depletion of memory resources. Over the last decade, however, processors for the IoT and IoE have improved; with increased operating power and memory resources, longer data bus widths and low power consumption. With the improvements made to processors suitable for building IoT devices, the question remains whether endpoint nodes should still be considered capable of only supporting the most lightweight of cryptographic mechanisms. We evaluate the capabilities of a device family (Cortex-M series processors) commonly found in programmable logic controllers (PLC) to implement standard, verified software cryptographic libraries in terms of execution times, memory occupation and power consumption in order to determine their adequacy for use in smart grid applications. It was seen that the MCUs were easily capable of running standard cryptographic algorithms. However, the use of public key cryptography may still require the inclusion of a hardware crypto accelerator or the use of a secure MCU implementing public key cryptography; as the relatively long execution times seen during the operation of, for example, ECDSA could be intolerable within a real time, IoE application.
Smart microgrid energy market: Evaluating distributed ledger technologies for remote and constrained microgrid deployments
(2021-03) Ledwaba, Lehlogonolo PI; Hancke, GP; Isaac, Sherrin J; Venter, HS
The increasing strain on ageing generation infrastructure has seen more frequent instances of scheduled and unscheduled blackouts, rising reliability on fossil fuel based energy alternatives and a slow down in efforts towards achieving universal access to electrical energy in South Africa. To try and relieve the burden on the National Grid and still progress electrification activities, the smart microgrid model and secure energy trade paradigm is considered— enabled by the Industrial IoT (IIoT) and distributed ledger technologies (DLTs). Given the high availability requirements of microgrid operations, the limited resources available on IIoT devices and the high processing and energy requirements of DLT operations, this work aims to determine the effect of native DLT algorithms when implemented on IIoT edge device so to assess the suitability of DLTs as a mechanism to establish a secure, energy trading market for the Internet of Energy. Metrics such as the node transaction time, operating temperature, power consumption, processor and memory usage are considered towards determining possible interferences on the edge node operation. In addition, the cost and time required for mining operations associated with the DLT-enabled node are determined in an effort to predict the cost to end users- in terms of fees payable and mobile data costs- as well as predicting the microgrid’s growth and potential blockchain network slowdown.
A threat-vulnerability based risk analysis model for cyber physical system security
(AIS Electronic Library, 2017-01) Ledwaba, Lehlogonolo PI; Venter, HS
The ability to network machinery and devices that are otherwise isolated is highly attractive to industry. This has led to growth in the use of cyber-physical systems (CPSs) with existing infrastructure. However, coupling physical and cyber processes leaves CPSs vulnerable to security attacks. A threat-vulnerability based risk model is developed through a detailed analysis of CPS security attack structures and threats. The Stuxnet malware attack is used to test the viability of the proposed model. An analysis of the Natanz system shows that, with an actual case security-risk score at Mitigation level 5, the infested facilities barely avoided a situation worse than the one which occurred. The paper concludes with a discussion on the need for risk analysis as part of CPS security and highlights the future work of modelling and comparing existing security solutions using the proposed model so to identify the sectors where CPS security is still lacking.
Trust requirements and mechanisms in peer-to-peer energy markets
(2024-11) Leotlela, Boitumelo; Ledwaba, Lehlogonolo PI; Coetzee, M
Peer-to-peer (P2P) energy markets are emerging as a promising solution to address the challenges faced by traditional energy systems. However, the decentralised nature of these markets necessitates robust trust mechanisms to ensure secure and reliable energy transactions. This paper presents a comprehensive review of trust requirements and trust-building mechanisms in P2P energy markets. It explores the role of blockchain technology, zero-trust architecture, and reputation systems in establishing trust among market participants. It identifies several trust requirements, including security, privacy, transparency, fairness, and reputation. The study further highlights the limitations of existing works and proposes future research directions to enhance trust and security in P2P energy markets. By addressing these limitations, the full potential of P2P energy trading can be unlocked, contributing to a more sustainable and resilient energy future.

Browsing by Author "Ledwaba, Lehlogonolo PI"

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