In Jan-May 2026, I will be teaching CS7260: Post-Quantum Cryptography.

Course Description


The course will cover the exciting impact on cryptography created by the advent of quantum computers. Quantum computers, which harness the power of quantum mechanics, have demonstrated surprising power over classical computers -- in particular, a famous algorithm by Shor demonstrates that most of modern cryptography, believed to be secure against classical computers, is completely insecure against quantum computers. Moreover, significant progress has been made in recent times to develop quantum computers, so it is an urgent need to base cryptography on problems that remain hard against quantum attackers. The field of post-quantum cryptography was born to fill this very gap.

In this course, we will study the mathematical foundations of post-quantum cryptography. This is an exciting emerging area with many many more questions than answers. We will study how to build cryptography from the hardness of problems in lattices, codes, multivariate quadratics and isogenies which are believed to withstand quantum attacks. We will pay particular attention to the cryptographic schemes that underlie the finalists of the NIST PQC competition. We will study the evidence we have for the hardness of these problems, and the properties of these mathematical structures that lend themselves to crypto design. We will NOT get into quantum computing at all.

Administrative Information


Lectures are Thursdays 2:00- 3:15 pm and Fridays, 3:30-4:45 pm.

Pre-requisites.

The course CS 6111 (Foundations of Cryptography) is not a pre-requisite for this course though it is helpful if you have studied it. This course requires mathematical maturity, in particular comfortable working knowledge of linear algebra and probability. The course will be entirely mathematical in nature and the material could be considered challenging, so please only sign up if you are really excited by puzzles and cryptography.

Requirements.


Policies and Grades.

Collaboration is encouraged but you must write up solutions on your own. You must also write the names of all the people you discussed the problem with. In case you find material that will help you in solving some problems, you should mention the source in your writeup. Class participation will also be taken into account when assigning grades.
I expect all students to behave according to the highest ethical standards. Any cheating or dishonesty of any nature will result in failing the class.

Resources.

For code based cryptography, we will follow these lecture notes by Thomas Debris-Alazard. For isogeny based crypto, we will follow these notes by Luca De Feo. For lattices, we will follow these notes by Regev.