Introduction to cryptography
I teach Introduction to cryptography [NDMI100] in the summer semester of 2025/2026. The lecture will cover the basics of both theoretical and practical cryptography, focusing on protocols currently used on the Internet.
Lectures will be on Tuesdays from 10:40 in S3.
If you want to consult anything, please write an e-mail to mares+kry@kam.mff.cuni.cz and we will discuss possibilities.
| date | topics | recording |
|---|---|---|
| 17. 2. | Cryptographic primitives: symmetric and asymmetric ciphers, hash functions, random generators. Protocols and roles. Kerckhoffs principle. Simple protocols: multi-party communication, signatures (symmetric and asymmetric) hybrid ciphers and signatures, challenge-response authentication. Designing an auction protocol: padding, nonces, sequence numbers, signatures, session IDs. | video |
| 24. 2. |
Plan:
Basic types of cryptographic attacks. Security level.
Different kinds of "Birthday attacks".
One-time pad and Vernam's cipher.
Perfect security and its limits.
Secret sharing and threshold schemes (Shamir's construction with polynomials).
Exercise: How to toss a coin over a phone call? |
Sources
- Previous runs of the lecture: 2025 (with video recordings), 2024 (with video recordings), 2023 (with video recordings), 2020 (partial recordings), 2019 (with Czech video recordings).
- My notes (in Czech), also for Double Ratchet and TLS.
- Study text (in Czech, very much work in progress)
- Niels Ferguson, Bruce Schneier: Practical Cryptography. Wiley Publishing, 2003.
- Jonathan Katz, Yehuda Lindell: Introduction to Modern Cryptography, 2nd Edition. CRC Press, 2015.
- Douglas Stinson, Maura Paterson: Cryptography – Theory and Practice. CRC Press, 2018.
- Dan Boneh, Victor Shoup: A Graduate Course in Applied Cryptography.
- Mike Rosulek: The Joy of Cryptography.
- Ross Anderson: Security Engineering, Wiley Publishing, 2008.
- Martin Mareš: Algoritmy okolo teorie čísel (in Czech).
- Ivan Ristić: Bulletproof SSL and TLS, Feisty Duck Publishing, 2nd edition, 2021.
- Moxie Marlinspike, Trevor Perrin: The Double Ratchet Algorithm