Physical-Layer Encryption Using Digital Chaos for Secure OFDM Transmission

Due to the broadcasting nature of passive optical network (PON), data security is challenging. For the transmission of orthogonal frequency division multiplexing (OFDM) signals, the high peak-to-average power ratio (PAPR) is considered as one of the major drawbacks. This chapter reviews the digital chaos-based secure OFDM data encryption schemes, where the transmission performance is improved via PAPR reduction. The digital chaos is incorporated into the signal scrambling approaches: selective mapping (SLM), partial transmit sequence (PTS); and precoding approaches: discrete Fourier transform (DFT) and Walsh-Hadamard transform (WHT) for PAPR reduction. Multi-fold data encryption is achieved with a huge key space provided by digital chaos, to enhance the physical-layer security for OFDM-PON, while the pseudo-random properties of digital chaos are applied for PAPR reduction, which consequently improves the transmission performance. The evidences of these encryption approaches are presented in terms of theories, simulations, as well as experimental demonstrations. The chaotic data encryption schemes could be promising candidates for next-generation OFDM-PON

The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden

High-rate continuous-variable measurement-device-independent quantum key distribution

We report the first continuous-variable measurement-device-independent QKD system generating secret keys at 5 MBaud without frequency and phase locking. We achieve this using a relay structure based on a polarization 90-degree optical hybrid and well-designed DSP

Industry approaches in handling online exploitation of children: A comparative study of the policy, guidelines and best practices in Malaysia, Singapore and Australia

AbstractChild Exploitation on the Internet is an issue of international importance. Despite notable efforts taken by nations to prevent the online exploitative use of children, the problem remains a serious issue. Although one entity cannot take responsibility for regulating the material, there seems to be an added responsibility placed on Internet Service Providers as gatekeepers of information on the Internet to take possible measures to regulate the material. This study focuses on industry regulatory initiatives, including policy, guidelines, and best practices that are enforceable by the communications and multimedia industry, with a focus on Content Service Providers in handling online exploitation of children in Malaysia. This article begins by examining the current legislative framework provided in the Communications and Multimedia Act of 1998 and the Content Code in Malaysia. The article then examines the Online Safety Act 2021 of Australia and the Online Safety (Miscellaneous Amendments) Act 2022 of Singapore, which was passed in Parliament on 9 November 2022, and takes effect from first NaN Invalid Date with a focus on industry service provider towards content regulation. Finally, the article concludes by proposing recommendations from the Australian and Singaporean legislative frameworks as points of reference for best practices in regulating content in Malaysia

Effects of imbalanced modulation in continuous-variable quantum key distribution

We experimentally investigate the impact of non-optimal state preparation on a Gaussian-modulated coherent state CVQKD system. We show that modulation with imbalanced strength in the amplitude and phase quadratures reduces the optimal key rate over certain distance.</p

Continuous-Variable Quantum Key Distribution Over 60 km Optical Fiber With Real Local Oscillator

We report the first continuous-variable quantum key distribution experiment that enables the generation of secure key over a 60 km fiber channel with locally generated local oscillator. This is achieved by controlling the excess noise using machine learning for phase noise compensation while operating the system at a low modulation variance

Practical Network Encryption with Quantum Cryptographic Keys

We present a state-of-the-art continuous-variable quantum cryptographic prototype that operates at 1550 nm and distributes keys across a 10 km fiber channel to network encryptors operating at 1300 nm and using the same (wavelength-multiplexed) channel for data link layer encryption