Math 252: Mathematics of Public-Key Cryptography (Spring 2023)

This course concerns the mathematical problems underlying public-key ciphers and digital signatures, as well as algorithms to solve them. Topics include discrete logarithms, integer factorization, elliptic curves, and lattices. These topics provide an appealing introduction to several topics in number theory, abstract algebra, and algorithms.

The course is designed for students with no prior experience in abstract algebra or programming. It serves as an introduction to those topics, meant to prepare students for more advanced courses. Students with prior experience are welcome, however.

You can find materials from previous offerings of this course here: 2022, 2020, 2019, 2016, 2015. The 2015 and 2016 courses, taught at Brown, were slightly different in style and emphasis.

Time and location

  • Monday, Wednesday, and Friday, 10:00-10:50am in SMUD 014.

Help hours

  • My office hours in SMUD 401:
    • Tuesday 2:00-3:30
    • Wednesday 2:30-4:00
    • Friday 1:30-2:30
  • Our math fellow (TA), Cailin Plunkett, will have office hours at the following times.
    • Monday 6:00-7:30pm in SMUD 007
    • Wednesday 6:00-7:30pm in SMUD 007

Handouts

Homework

Exams

  • Midterm 1 will be on Friday 3/10, in class.
    • Exam / Solutions
    • Remember to make a one-page note-sheet (front and back)! Tables 2.2 and 2.3 from the textbook (summary of Diffie-Hellman and Elgamal) will be included in the exam packet, so you do not need to copy any of that information to your note sheet.
    • Coverage: Anything discussed by Friday 3/3, and included on PSets 1 through 5. This includes the following textbook sections: 1.2, 1.3, 1.4, 1.5, 2.1, 2.2, 2.3, 2.4, 2.7 (but not 2.5 or 2.6).
    • Some old exams, for review. Note that coverage and emphasis differs on these exams, and in particular the 2015 and 2016 exams are somewhat more difficult that ours is likely to be. Solutions will be posted in the week before the midterm.
  • Midterm 2 will be on Friday 4/28, in class.
    • Exam / Solutions
    • Remember to make a one-page note-sheet (front and back)! Summary tables for all cryptosystems we’ve studied will be included in the exam packet, so you do not need to copy any of that information to your note sheet.
    • Coverage: Anything discussed by Wednesday 4/19, and included on PSets 6 through 10. This includes textbook sections 2.8-9, 3.1-4, 4.1-3, 6.1-4.
    • Some old exams, for review. Note that coverage and emphasis differs on these exams, and in particular the 2015 and 2016 exams are somewhat more difficult that ours is likely to be. Solutions will be posted in the week before the midterm.
  • The final exam will be on Thursday 5/18, 2-5pm, in SMUD 206.
    • Exam / Solutions
    • Remember to make a one-page note-sheet (front and back)! Summary tables for all cryptosystems we’ve studied will be included in the exam packet, so you do not need to copy any of that information to your note sheet.
    • Coverage: cumulative, including all course material. The material after Midterm 2 will have slightly higher weight, since it has not yet been covered on an exam.
    • Some old final exams.