SACM - United Kingdom
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9667
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Item Restricted Exploring the Hardware Design Space for Practical Lattice-Based Post-Quantum Cryptography(Saudi Digital Library, 2026) Alotaibi, Ahmed; Benaissa, MohammedAs quantum computing advances threaten to undermine classical encryption schemes, cryptography must evolve to maintain secure communication. Modern cryptographic standards will soon be replaced by recent Post-Quantum Cryptography (PQC) standards developed to mitigate the risks posed by quantum computing. However, this transition introduces increased computational overhead, creating a heightened demand for efficient hardware accelerators to achieve practical performance. Among PQC propositions, lattice-based schemes are considered leading contenders due to their robust mathematical security foundations. Nevertheless, their practical deployment is hindered by performance bottlenecks, notably the computational cost of polynomial multiplication, which drives key generation, encryption, and decryption. This thesis addresses this challenge by investigating the optimisation of polynomial multiplication in lattice-based schemes through hardware acceleration. It reviews both time-domain (e.g., schoolbook, Karatsuba, Toom–Cook) and frequency-domain (e.g., Number Theoretic Transform (NTT)) methods, identifying modular arithmetic as the primary bottleneck. To tackle this, the thesis presents two constant Barrett modular multiplication algorithms: the constant Barrett and a novel Truncated Modulus-Size Constant Barrett (TMSCB) variant. Complexity analysis and FPGA implementations demonstrate that the proposed TMSCB algorithm achieves up to a 2.8$\times$ reduction in area--time product compared to classical Barrett and up to a 1.4$\times$ reduction compared to constant Barrett at larger operand sizes, while reducing register usage by approximately 16.7\%. These algorithms are then integrated into scalable NTT hardware accelerators for ML-DSA and Falcon schemes. The designs exploit DSP slice efficiency, achieving execution-time reductions of up to 46.7\% and hardware area savings of up to 35.4\%, while improveing speed and resource utilisation. In addition, a parametric and scalable schoolbook-based polynomial multiplier is proposed for time-domain multiplication, exploiting coefficient splitting and truncation for power-of-two moduli and achieving execution-time reductions of 36--51\%. Overall, this research enhances the practicality of post-quantum cryptographic hardware by optimising polynomial multiplication, enabling high-performance and deployable implementations.4 0Item Restricted Demographic Patterns and Transfusion Implications of Foetal Haemoglobin (HbF) in Blood Donors in England(Saudi Digital Library, 2025) Alotaibi, Ahmed; Wright, SaraBackground Foetal haemoglobin (HbF) normally declines to <1 % in healthy adults, but persistence can complicate haemoglobinopathy screening, neonatal transfusion, and laboratory interpretation. In the United Kingdom (UK), the adult threshold of <1 % was derived from predominantly White cohorts using pre-high-performance liquid chromatography (HPLC). Contemporary donor-based data are limited, and the relevance of this cut-off in a diverse donor base is uncertain. Aim To estimate the prevalence of elevated HbF (>1 %) in a current National Health Service Blood and Transplant (NHSBT) donor cohort and assess demographic associations with sex, ethnicity, and age. Methods A retrospective cross-sectional study analysed 579 anonymised donations processed at NHSBT Filton in June 2025. HbF was quantified on a Tosoh HLC 723 G8 HPLC platform (limit of quantification 0.1 %, coefficient of variation (CV) < 2 %). Prespecified non-parametric analyses included Mann-Whitney U (sex), Kruskal-Wallis H (ethnicity), and Rho-Spearman’s correlation coefficient (ρ) (age). Wilson and bootstrap methods generated 95 % confidence intervals for prevalence estimates. Results HbF ranged from 0.10 % to 2.90 % (median 0.50 %, interquartile range [IQR] 0.30-0.60 %). Twenty-nine donors (5.01 %) had HbF > 1.0 % (95 % confidence interval [CI]: 3.51-7.10, bootstrap CI: 3.28-6.91). Females had significantly higher HbF than males (p < 0.001, rank biserial correlation coefficient [r_rb] = 0.192). No significant differences were observed between White, Asian, and Black donors (p = 0.152), and HbF showed a weak inverse correlation with age (ρ = –0.083, p = 0.045). Conclusions One in twenty screened blood donors in this cohort had HbF > 1 %. These data suggest mild HbF elevations may be more common in contemporary donors than assumed. Larger, multi-centre studies with genetic and clinical follow-up are needed to determine whether sex- or context-specific thresholds improve diagnostic specificity without compromising haemoglobinopathy detection.11 0Item Restricted Effectiveness of the NIST Cybersecurity Framework in Small and Medium Enterprises (SMEs) in the UK.(Saudi Digital Library, 2025-05) Alotaibi, Ahmed; Lamoyero, ZaynabSmall and medium-sized enterprises (SMEs) in the UK confront more sophisticated and frequent cyber risks in today's linked environment. This research examines UK IT-related SMEs' adoption and efficacy of the NIST Cybersecurity Framework (CSF). The research evaluates SMEs' cybersecurity issues, NIST CSF's response, and its implementation hurdles. The quantitative study surveys IT managers, cybersecurity professionals, and company owners to assess SMEs' cybersecurity practices, framework adoption, and problems. Results revealed that although many SMEs see the relevance of NIST CSF, complexity, lack of technical competence, and budget restrictions limit its implementation. The structure improves cybersecurity, but the absence of formal training and top management backing is a major drawback. The results suggest simplifying the framework, engaging in training, and finding external expert advice to speed up NIST CSF implementation for SMEs. The research also proposes that politicians and industry groups must raise awareness, provide funding, and create sector-specific cybersecurity frameworks. Focusing on UK SMEs and self-reported data may bias the research. Fu study should compare NIST CSF adoption across geographies and industries and examine its long-term effects. The results improve SME cybersecurity resilience and NIST CSF adoption insights31 0Item Restricted Enhancing prehospital triage for patients with suspected cardiac chest pain using prediction models(University of Manchester, 2024-05-14) Alotaibi, Ahmed; Body, Richard; Brown, Benjamin; Martin, GlenBackground: Chest pain, a primary symptom of acute coronary syndromes (ACS), frequently prompts ambulance calls and emergency department (ED) visits. Despite this, a significant number of patients transported for chest pain ultimately receive diagnoses of self-limiting, non-cardiac conditions. This leads to systematic over-triage, elevating ambulance resource utilization and contributing to crowding in EDs. Aim: To understand and improve the accuracy of current processes for telephone triage and prehospital assessment of patients with acute chest pain. For telephone triage, specific objectives included to systematically review the literature; gain consensus on the life-threatening conditions (LTCs) that should be identified by call handlers; and to derive and validate a prediction model. I also aimed to refine and validate prediction models to enhance prehospital risk stratification by paramedics. Methods: I completed (a) a systematic review searching three databases with narrative synthesis; (b) a Delphi study to define the LTCs that should guide future telephone triage; and (c) a retrospective cohort study using North West Ambulance Services (NWAS) data linked with Manchester University NHS Foundation Trust (MFT) to derive and validate a prediction model. Further, I completed secondary analyses of a multi-centre prospective diagnostic test accuracy study to create meta-models of established decision aids using stacked regression, and I validated the Manchester only Acute Coronary Syndrome ECG (MACS-ECG) prediction model in prehospital setting. Result: The systematic review identified three relevant papers supporting the feasibility of using prediction models to reduce over-triage by telephone but highlighting a paucity of data. The Delphi study identified 26 LTCs that should receive a priority 1 or 2 ambulance response. Due to a cyber-attack, results of the derivation and validation of a new prediction model for telephone triage cannot be presented. The existing MACS-ECG risk model achieved a sensitivity of 2.3% (95% CI 0.3-8.1%) and specificity of 99.5% (95% CI 98.6-99.9%) for myocardial infarction with poor calibration (gradient 0.0628, intercept 0.0852). Meta-modelling did not enhance the accuracy of established prediction models. The paramedic ECG interpretation showed a 30.8% (95% CI: 22.1-40.6%) sensitivity and 89.7% (95% CI: 87.2-91.9) specificity. Conclusions: This work has (a) identified an important evidence gap to guide telephone triage for chest pain, (b) defined outcome measures for such future research, and (c) identified that currently available prediction models do not have any advantage over human interpretation of an ECG by a paramedic. Future research should focus on completing the work to develop a new prediction model a telephone triage and supporting training paramedics for ECG interpretation.22 0Item Restricted Intraoperative blood pressure management and postoperative acute kidney injury: Systematic review(Saudi Digital Library, 2023-09-21) Alotaibi, Ahmed; Prowle, JohnBACKGROUND: Postoperative acute kidney injury (PO-AKI) represents a significant and potentially severe complication following surgery. This systematic review aims to examine the impact of goal-directed therapy (GDT) on the incidence of PO-AKI in adult patients who underwent major noncardiac surgery. METHOD: We adhered to the PRISMA guidelines to evaluate GDT versus conventional therapies in adult surgical patients. MEDLINE (via PubMed) was scoured from 2018 to May 2023 for relevant RCTs. Participants included adults undergoing major abdominal surgeries, with exclusions. Primary outcomes focused on post-operative acute kidney injury, with secondary outcomes assessing hospital stay length and 30-day mortality. RESULT: Of 27,243 initial citations, 6 single-centre RCTs were included, encompassing 652 patients and classified into Blood Flow Optimization (BFO) and Perfusion Pressure Optimization (PPO). The primary outcome was reported in all. Various AKI definitions were used, including KDIGO, RIFLE, and AKIN. BFO trials explored blood flow strategies impacting PO-AKI incidence, with mixed results. PPO studies assessed perfusion pressure's role in PO-AKI, one showing significantly reduced AKI incidence. Secondary outcomes were the hospital stay length and 30-day mortality, with no consistent trend across studies. The risk of bias assessment highlighted challenges in blinding and statistical planning, with two trials deemed low risk. CONCLUSION: The body of evidence gathered from these studies, including the OPTIMISE trial, suggests that while GDT strategies do not consistently reduce the incidence of PO-AKI, they may still influence other postoperative outcomes. Given the significant morbidity and mortality associated with PO-AKI, further research in this area is warranted to optimize perioperative care strategies. Future research should include multi-centre RCTs with larger sample sizes, consider the definition of AKI, and account for the protocol being implemented.16 0