Modern Cryptography
JHU 601.442/642 · Spring 2026
Course Information
- Time
- 3-4:15pm, Tuesday and Thursday
- Location
- Hodson 203
- Instructors
-
- Harry Eldridge
- Email: heldrid2@jhu.edu
- Office Hours: Tuesday 11am-12pm, Malone 307
- Aditya Hegde
- Email: ahegde3@jhu.edu
- Office Hours: Wednesday 4-5pm, Malone 307
- Harry Eldridge
- TA
-
- Shruthi Prusty
- Email: sprusty1@jhu.edu
- Office Hours: Thursday 1-2pm, Malone 216
- Shruthi Prusty
- Grading
- 15% Midterm 1, 25% Midterm 2, 30% Final, 25% Homework, 5% Class Participation
- Website
- adishegde.github.io/modern_crypto_sp26
- Discussion Board
- Canvas
- Homeworks
- Submit via Canvas
- Syllabus
Homeworks
Homeworks are due at 11:59pm Eastern Time on the listed due date. You have a total of 48 late hours without penalty1. Exceptions and extensions can be given in exceptional circumstances; please contact the course instructor to discuss your circumstances.
Collaboration on homeworks is allowed, though the final words used in the assignment must be your own. When collaborating with other students you are required to state at the beginning of the submission the names of the students you collaborated with.
All homework submissions must be typeset (no handwritten submissions). We highly recommend writing in LaTeX or Typst. You might find this LaTeX solution template helpful to get started.
- Homework 1. Release Date: January 22, 2026. Due Date: January 29, 2026.
- Homework 2. Release Date: January 29, 2026. Due Date: February 5, 2026.
- Homework 3. Release Date: February 5, 2026. Due Date: February 12, 2026.
- Homework 4. Release Date: February 19, 2026. Due Date: February 26, 2026.
Solutions
Homework solutions can be found in Canvas under “Modules” => “Homework Solutions.”
Resources
There is no required textbook. We recommend using “A Graduate Course in Applied Cryptography” by Dan Boneh and Victor Shoup as supplemental text (aka the Boneh-Shoup book). Any references to this book in additional readings correspond to version 0.6. A few additional references are listed below.
Lecture Notes:
- Fall 2022 Lecture Notes
- A Course in Cryptography, Rafael Pass and Abhi Shelat
- Lecture Notes on Cryptography, Shafi Goldwasser and Mihir Bellare
- Introduction to Modern Cryptography, Mihir Bellare and Phillip Rogaway
- Intensive Introduction to Cryptography, Boaz Barak
Books:
- Introduction to Modern Cryptography, Jonathan Katz and Yehuda Lindell.
- Foundations of Cryptography: Volume 1, Basic Tools, Oded Goldreich.
- Foundations of Cryptography: Volume 2, Basic Applications, Oded Goldreich.
Definitions:
A list of the definitions that we discuss in class can be found here
For example, you could submit homework 1 three hours late, homework 2 ten hours late, and homework 5 thirty-five hours late and receive no penalty. Homeworks submitted at any time past the hour count as consuming a late hour. For example, submitting a homework at 1:00am Eastern Time the day after it is due would consume two late hours. Homeworks submitted after all 48 late hours have been consumed will be worth 0.↩︎
Class Schedule
| Date | Topic | Slides | Notes |
|---|---|---|---|
| Jan 20 | Introduction and Prerequisites | Required Reading: Notes on prerequisites | |
| Jan 22 | Perfect Security | Additional Reading: Sections 2.1.1 and 2.1.2 from the Boneh-Shoup Book. | |
| Jan 27 | Limitations of Perfect Security | Additional Reading: Section 2.1.3 from the Boneh-Shoup Book. | |
| Jan 29 | Computational Security | Additional Reading:
|
|
| Feb 3 | Pseudorandomness | Additional Reading: Sections 3.1 to 3.3 from the Boneh-Shoup Book. | |
| Feb 5 | Pseudorandomness II | Additional Reading: Sections 3.4 to 3.12 from the Boneh-Shoup Book. | |
| Feb 10 | Pseudorandomness II and Proof Techniques | Additional Reading:
|
|
| Feb 12 | Pseudorandomness III and Midterm Review | ||
| Feb 19 | Pseudorandomness IV and Encryption I | Additional Reading: Sections 5.1-5.4 from the Boneh-Shoup Book, which go over constructing encryption schemes for messages of variable length. |
|
| Feb 24 | Encryption II |