Foundations of Cryptography

CS60088, Spring 2026, LTP: 3-1-0

Notices and Announcements

• First test to be held on 16th of February 2026 during class hours
• Approval decisions for subject registration will be based on CGPA. Those who are not familiar with the course prerequisites (mentioned below) are strongly discouraged from joining this course.
• Classes start on 5rd of January 2026.

Prerequisites

We assume basic familiarity with probability theory, algebraic structures (groups, rings, fields), linear algebra and algorithms. Some exposure to computational complexity is useful as well. These topics will not be covered in the course. No prior exposure to cryptography is necessary.

Syllabus (Tentative)

• Introduction to Cryptography
• Perfect secrecy -- definition, equivalent definitions, one-time pads, limitations of perfect secrecy, Shannon's theorem
• Computational secrecy -- motivating the need for computational secrecy, formalising security under different threat models, reductionist arguments and hardness assumptions
• Symmetric Encryption from psedorandom generators, pseudorandom functions and permutations
• Message authentication codes (MACs), hash functions and their security definitions, provably secure constructions
• Practical Constructions of symmetric encryption, MACs and hash functions
• Public key encryption
• Signatures
• Introduction to one-way functions, constructing one-way functions from assumptions such as RSA, Discrete logarithm, hard-core predicates, construction of pseudorandom objects from one-way functions

References

• Jonathan Katz and Yehuda Lindell, Introduction to Modern Cryptography, Chapman and Hall/CRC Press, 2007.
• Shafi Goldwasser and Mihir Bellare, Lecture Notes on Cryptography, 2008 (available here).
• Oded Goldreich, The Foundations of Cryptography, Volume 1 and Volume 2, Cambridge University Press, 2001 and 2004.
• Mike Rosulek, The Joy of Cryptography, MIT Press, 2017 .
• Wenbo Mao, Modern Cryptography: Theory and Practice, first edition, Pearson Education, 2004.

Evaluation (tentative)

Tests/Exams

Term paper + Presentation

Below is a list of topics for the term paper. You are free to choose any topic outside of this list as long as it aligns with the theme of the course. Please contact the instructors if you need help finding reading material related to your topic.

The report (prepared in LaTeX) should discuss in detail atleast one non-trivial result with a complete analysis. It should be self-contained with an introduction explaining the importance of the topic. Pay attention to language aspects such as grammar and spelling. You are allowed to use material from other sources. But, you must understand and express in your own language and provide proper references. Directly copying from other sources is forbidden and will be heavily penalised.

Evaluation criteria are as follows.

Report:

• introduction,
• clarity of exposition,
• content covered,
• insights/criticisms/comments of your own, if any.

• level of understanding,
• clarity of presentation,

Lectures