Chameleon: a Blind Double Trapdoor Hash Function for Securing AMI Data Aggregation

Data aggregation is an integral part of Advanced Metering Infrastructure (AMI) deployment that is implemented by the concentrator. Data aggregation reduces the number of transmissions, thereby reducing communication costs and increasing the bandwidth utilization of AMI. However, the concentrator poses a great risk of being tampered with, leading to erroneous bills and possible consumer disputes. In this paper, we propose an end-to-end integrity protocol using elliptic curve based chameleon hashing to provide data integrity and authenticity. The concentrator generates and sends a chameleon hash value of the aggregated readings to the Meter Data Management System (MDMS) for verification, while the smart meter with the trapdoor key computes and sends a commitment value to the MDMS so that the resulting chameleon hash value calculated by the MDMS is equivalent to the previous hash value sent by the concentrator. By comparing the two hash values, the MDMS can validate the integrity and authenticity of the data sent by the concentrator. Compared with the discrete logarithm implementation, the ECC implementation reduces the computational cost of MDMS, concentrator and smart meter by approximately 36.8%, 80%, and 99% respectively. We also demonstrate the security soundness of our protocol through informal security analysis

5G-Wi-SUN for Building Management System

With higher data rates and lower latency, 5G constitutes a mobile alternative to both wired networks and less capable wireless solutions. However, the performance of 5G requires expensive hardware and high energy consumption, making it less suitable for energy-constrained edge devices. Combining the capabilities of 5G for Wide Area Network (WAN) access, with the benefits of other wireless networks purpose-built for low-power embedded systems, a Building Management System (BMS) based on 5G can be deployed anywhere in a building with 5G coverage extended with a suitable LPWAN connectivity for IoT devices of the BMS. In this paper, the LPWAN of choice is the Wireless Smart Utility Network (Wi-SUN), a low-power sub-GHz connectivity based on IEEE 802.15.4g, offering mesh and multi-hop features for improved reliability and range, alongside competitive data rates. The performance of a 5G-Wi-SUN hybrid network was evaluated with a fibre-broadband hybrid network, a 5G-only network and a Wi-SUN-only network to determine the feasibility of 5G-Wi-SUN network. Test results show a significant performance of our 5G-WiSUN network, with a round-trip times below half a second in most cases, and a trimean of 115ms, only 27ms more than the fibre broadband-WiSUN network in our experiment. Consequently, the results have demonstrated the ability of a 5G-Wi-SUN network to provide a versatile alternative to fibre broadband-WiSUN, while maintaining a comparable performance

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Studies on Characteristics of Rain Fade at 23 GHz for Terresterial Links

-Terrestrial links operating at frequencies higher than IO GHz suffers degradation due to rain. Various researches have been conducted to study rain-induced degradations such as rain attenuation. Apart from rain attenuation, rain fade is also a major factor affecting the performance of a terrestrial microwave link. This paper therefore, seeks to investigate the impacts of rain fade to the performance of terrestrial microwave links. In this paper, rain fade slope and rain fade depth are investigated and analyzed. The superposition of rain attenuation and rain fade is also investigated. Signal fall time and recovery time are also major concern n this paper. All the analysis leads to understanding on the impacts of rain fade on the performance and reliability of microwave terrestrial links

Energy/bandwidth-Saving Cooperative Spectrum Sensing for Two-hop WRAN

A two-hop wireless regional area network (WRAN) providing monitoring services operating in Television White Space (TVWS), i.e., IEEE P802.22b, may employ a great number of subscriber customer-premises equipments (S-CPEs) possibly without mains power supply, leading to requirement of cost-effective and power-saving design. This paper proposes a framework of cooperative spectrum sensing (CSS) and an energy/bandwidth saving CSS scheme to P802.22b. In each round of sensing, S-CPEs with SNRs lower than a predefined threshold are excluded from reporting sensing results. Numerical results show that the fused missed-detection probability and false alarmprobability could remainmeeting sensing requirements, and the overall fused error probability changes very little. With 10 S-CPEs, it is possible to save more than 40% of the energy/bandwidth on a Rayleigh channel. The principle proposed can apply to other advanced sensing technologies capable of detecting primary signals with low average SNR