General Information

Instructor: Huijia (Rachel) Lin, rachel(at)cs

TA: hanjul (at) cs

Time and location:

• Class: Monday/Wednesday 10:00am-11:20pm, CSE2 271

Office hours:

• Rachel Lin: Monday 4:00pm-5:00pm, CSE 652 and on Zoom
• Hanjun Li: Tuesday 4:00pm-5:00pm, Allen 5th Floor Breakout and on Zoom

Discussion: We are going to use Edstem Board. Notes and reading material will also be posted at Edstem.

Homework: Homework will be handled using Gradescope (UWnetid protected).

Topics

Cryptography provides important tools for ensuring the confidentiality and integrity of sensitive digital data. Core cryptographic tools, such as encryption, message authentication codes, and hash functions, are widely deployed to protect data that is communicated across the Internet and that is used in every domain including finance, commerce, healthcare, infrastructure, and national security. Our entire modern way of life would collapse without these tools. As society adapts to enjoy new computing technologies (e.g., artificial intelligence, precision health, and smart devices) that reap the benefits of learning from private data, the conflict between privacy and utility is becoming increasingly contentious. It is thus imperative to develop tools that enable utilizing the data while protecting them simulatneously. To this end, magical cryptographic objects, such as zero-knowledge proofs, secure multi-party computation, fully homomorphic encryption, and program obfuscation have emerged.

This course gives an introduction to these gems in cryptography, as well as the the mathematical frameworks and methodologies that modern cryptography has developed over the past decades. The first half of the class will focus on core cryptographic tools (e.g., encryption, message authentication, hash functions, etc.) while the second half will introduce more powerful objects (e.g., fully homomorphic encryption, program obfuscation). In order to cover all these gems, we will put more emphasis on ideas, and perfer simple constructions for illustrating a notion, over the most efficient and optimized versions.

Prerequisite: Most importantly, students should be ready to read and write (and even enjoy!) mathematical definitions and proofs. We will assume basic knowledge of discrete probability (e.g., events, random variables, expectations, conditional probability, Chernoff, union bound) / basic algebra (e.g., modular arithmetics, matrixes, vectors, some group theory that can be picked up along the way) / number theory (e.g., primes, greatest common divisor), and theory of computing (e.g., the big-Oh notation, running time analysis, NP reduction). If a student is mathemathically mature, most of these prerequisite can be picked up along the way.

Resources

There is no mandatory textbook. Notes and reading material will be posted on Edstem. Following is a list of great resources to reference to.

• Boaz Barak. An Intensive Introduction to Cryptography (Recommended! we will follow a similar pace as this class.)
• R. Pass and a. shelat. A Course in Cryptography (fun and intuitive lecture notes for an undergrad crypto class, focusing on theory)
• O. Goldreich. The Foundations of Cryptography (a thorough and formal textbook on foundations.)
• J. Katz and Y. Lindell. Introduction to Modern Cryptography (a textbook, relatively easy entry)
• D. Boneh and V. Shoup A Graduate Course in Applied Cryptography (a textbook on applied cryptography)

Grading:

There will be four homework, each of which accounts for 10% of points. Students are responsible for scribing notes for one or two class, which together with attendence, in person or virtually, counts as 10% of the points. The remaining 50% of the points will be assigned to either a take-home final exam, or a project, by your choice. Homework can be solved in teams of 2, and each team has a total of 6 late days for homework submission, which can be used in any fashion.