CAREER: Quantum Cryptography: Towards New Functionalities and Foundations

Quantum computers will fundamentally change the landscape of cryptography. On the one hand, they challenge the security of widely deployed encryption schemes by efficiently solving problems such as factoring and discrete logarithms. On the other hand, the ability to process and exchange quantum information opens the possibility of realizing cryptographic functionalities that are entirely unattainable with classical capabilities alone. In recent years, the field has entered a new phase focused on understanding how quantum information and computational hardness can be combined to unlock these new capabilities. Motivated by this shift, the overarching goal of this project is to investigate how uniquely quantum phenomena, such as the no-cloning principle and entanglement, interact with computational hardness to enable new forms of security and verification. These investigations will strengthen our understanding of quantum information as a resource in cryptography and in computation more broadly, and may reveal new connections with complexity theory and algorithms. In parallel, the investigator will develop coursework in quantum computation and cryptography, mentor undergraduate and graduate researchers, and organize outreach activities that introduce high school students to quantum computing. This project will pursue three main directions. First, the investigator will design novel protocols to realize cryptographic functionalities that are unattainable classically, including copy-protection of software, and stronger forms of encryption with unclonable ciphertexts. Second, the investigator will study inherently quantum computational problems that can serve as minimal building blocks for cryptography, with the goal of characterizing the computational assumptions necessary and sufficient for quantum cryptography. Third, the investigator will develop simple and efficiently verifiable protocols for demonstrating quantum advantage using cryptographic techniques, with the goal of reducing the complexity of existing protocols and enabling implementations on near-term devices. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.