Public PhD Viva-Voce Examination of Ms. Wafa Ahmed Naji Al-Nabhani

The Public Viva-Voce Examination for the PhD Dissertation hereto entitled, An Intelligent and Adaptive Blockchain-Based Model for Internet of Things Applications in Healthcare, submitted by Ms. Wafa Ahmed Naji Al-Nabhani, to Department of Information Technology, Faculty of Computer and Information Technology – Sana’a University, was held on Wednesday, Dhu al-Qadah 2, 1446 Hijri, corresponding to April 30, 2025. The Viva-Voce Committee, which was formed based on a resolution issued by the Post-Graduate Studies and Scientific Research Council, consisted of the following members:

• Ammar Thabet Zuhari (Main superior and chairperson),
• Adnan Yahya Al-Mutawakel (Internal Examiner), and
• Prof. Farouq Abdo Al-Fuhaidi (External Examiner)

This dissertation aimed to develop three proposed models: OABAC-HF, an enhanced version with higher performance (OABAC-HF-B), and OABAC-HF-BMT, which supports multithreading to improve response speed. This was achieved by addressing limitations identified in previous studies and exploring the impact of integrating multithreading with a batching algorithm within an access control system, simulating real-world conditions in healthcare applications.

The dissertation reached several key findings, including:

• A 99% improvement in response time compared to previous studies.
• A 95% improvement in execution time compared to prior work.
• A doubling of the number of processes that can be handled compared to previous research.

The dissertation suggests several recommendations, most notably:

• Expanding the models to operate across multiple blockchain platforms such as Ethereum, Corda, and Binance Smart Chain.
• Supporting cross-chain communication protocols for seamless data exchange in heterogeneous environments.
• Implementing the models in real-world healthcare settings to evaluate practical performance and compatibility with existing health systems.
• Investigating quantum-resistant security by developing quantum-resistant encryption algorithms.
• Employing the model in other sectors such as finance, supply chains, and smart cities.
• Integrating federated learning with blockchain to achieve secure health analytics while preserving patient data privacy.

The defense was attended by a number of academics, researchers, and interested individuals, in addition to the candidate’s colleagues and family members.

The PhD dissertation was examined and recommended by the Viva-Voce Committee for acceptance and approval. The Candidate was recommended to be awarded the degree of PhD in Information Technology.