Grant: Discovery Grants Program - Individual

The ubiquity of computers, in all forms, shapes, and sizes, has changed the daily life of most people in a multitude of ways. For example, we use these systems to make decisions, to entertain ourselves, to receive, record and/or broadcast all sorts of information. This undeniable presence of computers in our lives signifies the importance of the security of the systems and the information stored on or communicated through them. Any security issue on these systems can negatively impact the users' lives, in different ways. The security of computer systems can be studied from different perspectives including hardware, software, protocols used in the systems, physical location of the systems, and the policies around using them. In my research, I focus on cryptographical schemes used in the design of secure protocols. Generally, in cryptography, the schemes are said to be either computationally secure (comp. sec.) or information-theoretically secure (IT sec.). The security of most cryptosystems we use relies on the infeasibility of solving an underlying problem efficiently and the secrecy of the secret key, so they are comp. sec. Hence, most of these systems will not be secure if the adversary has access to the technology necessary to solve the underlying problem or to search for the key, both of which can be expedited using quantum computers. On the other hand, the security of an IT sec. cryptosystem only depends on the amount of information provided to the adversary, and not on their computational power. Thus, these systems will remain secure, regardless of the computing models used, e.g., quantum computers. Secret sharing and threshold schemes mostly provide IT security. The nature of these schemes makes them a perfect option for secure distributed storage and secure transportation of data via fragments. Various methods have been proposed for either problem; however, they mostly use comp. sec. schemes. This program of study aims to construct IT sec. schemes, to design protocols utilizing them, and to develop applications which will remain secure even after the advent of quantum computers. For the near future, the major focus will be on schemes, protocols, and applications related to IT sec. distributed systems. Towards this end, we design schemes and protocols. Then, we analyze their security properties. Finally, we implement them into real-world applications. The outcomes of this research program will benefit Canadian society overall, as well as minorities and marginalized communities. Regarding the former group, this objective is pursued through designing and implementing IT sec. distributed storage systems for public services, e.g., healthcare and civil services. The use of these schemes in the development of censorship-resistant systems for publishing, broadcasting, and file-sharing will serve the latter group more directly. Finally, the HQP trained in this program will be equipped with skills transferable to a wide range of careers.