Date of Graduation


Document Type


Degree Name

Doctor of Philosophy in Computer Science (PhD)

Degree Level



Computer Science & Computer Engineering


Brajendra Panda

Committee Member

Susan Gauch

Second Committee Member

Paul Cronan

Third Committee Member

Miaoqing Huang


Cybersecurity, Data Integrity, Data recovery, Fog Computing, Intelligent Systems, Malicious Transactions


The advancement of information technology in coming years will bring significant changes to the way sensitive data is processed. But the volume of generated data is rapidly growing worldwide. Technologies such as cloud computing, fog computing, and the Internet of things (IoT) will offer business service providers and consumers opportunities to obtain effective and efficient services as well as enhance their experiences and services; increased availability and higher-quality services via real-time data processing augment the potential for technology to add value to everyday experiences. This improves human life quality and easiness. As promising as these technological innovations, they are prone to security issues such as data integrity and data consistency. However, as with any computer system, these services are not without risks. There is the possibility that systems might be infiltrated by malicious transactions and, as a result, data could be corrupted, which is a cause for concern. Once an attacker damages a set of data items, the damage can spread through the database. When valid transactions read corrupted data, they can update other data items based on the value read. Given the sensitive nature of important data and the critical need to provide real-time access for decision-making, it is vital that any damage done by a malicious transaction and spread by valid transactions must be corrected immediately and accurately. In this research, we develop three different novel models for employing fog computing technology in critical systems such as healthcare, intelligent government system and critical infrastructure systems. In the first model, we present two sub-models for using fog computing in healthcare: an architecture using fog modules with heterogeneous data, and another using fog modules with homogeneous data. We propose a unique approach for each module to assess the damage caused by malicious transactions, so that original data may be recovered and affected transactions may be identified for future investigations. In the second model, we introduced a unique model that uses fog computing in smart cities to manage utility service companies and consumer data. Then we propose a novel technique to assess damage to data caused by an attack. Thus, original data can be recovered, and a database can be returned to its consistent state as no attacking has occurred. The last model focus of designing a novel technique for an intelligent government system that uses fog computing technology to control and manage data. Unique algorithms sustaining the integrity of system data in the event of cyberattack are proposed in this segment of research. These algorithms are designed to maintain the security of systems attacked by malicious transactions or subjected to fog node data modifications. A transaction-dependency graph is implemented in this model to observe and monitor the activities of every transaction. Once an intrusion detection system detects malicious activities, the system will promptly detect all affected transactions. Then we conducted a simulation study to prove the applicability and efficacy of the proposed models. The evaluation rendered this models practicable and effective.