CO 485The Mathematics of Public-Key Cryptography
- Units
- 0.50
- Faculty
- Mathematics
When it runs
- F24
- W25
- S25
- F25
- W26
- S26
- F26
- W27
- S27
Ran in 3 of the last 7 terms. Winter 2027: not on the schedule. Spring 2027: schedule not out yet.
An in-depth study of public-key cryptography. Number-theoretic problems: prime generation, integer factorization, discrete logarithms. Public-key encryption, digital signatures, key establishment, elliptic curve cryptography, post-quantum cryptography. Proofs of security.
Prerequisites
- Complete all of the following
- Complete 1 of the following
- Must have completed at least 1 of the following:
- Must have completed at least 1 of the following:
- PMATH345
- PMATH346
- Earned a minimum cumulative overall average of 80
- Complete 1 of the following
Antirequisites
None listed.
Leads to
No course lists it as a requisite.
Fall 2026 sections
| Section | Class | Enrolled | Meets |
|---|---|---|---|
| LEC 001 | 5963 | 13 / 20 | TTh 11:30–12:50 |
Reviewed on UW Flow
92% liked it30% easy75% useful
From 12 ratings and 2 comments on UW Flow. The most helpful comments, quoted as written, without names. Read them all on UW Flow.
Amazing course that covers "the fun crypto" if you're a mathy person like me.
Included in my offering: review and deeper treatment of basic number theory, a formal look at RSA, elliptic curves with some algebraic geometry, isogenies and a glimpse of pairings towards the end. Implementation details (e.g. efficient computation of 2^n/3^m-isogenies) are covered, which is great.Dec 2020 · liked itOn UW FlowRemove this
This is cross-listed with CO 685, which is a first year grad course, so prepare to do some work. Very mathy but overall an interesting course to get into mathematical security.
Dec 2015 · liked itOn UW FlowRemove this
Discussed on r/uwaterloo
30 posts and comments in 25 threads mention CO 485, March 2015 to December 2024. Quoted word for word, newest first; each reply sits under the post and the comment that started its branch. Search r/uwaterloo for newer posts.
Fall 2023
I don’t know what to do with my degree 1 point, 14 comments
“I'm in my 2A term as a math student and my initial plans were to get into data science, but due to my average being lower than the cutoff that did not happen. …”
u/Organic_Midnight1999: “Bro a Math degree is underrated. As the world advances the problems we face just get harder and harder. We move towards more high level, abstract, and data driven problems - guess what? …”
u/jadedwolf12: “… CO 454 - similar to 353, with a bigger focus on scheduling algorithms CO 485/487 - both cover cryptography, though 485 is more theoretical and focused on public-key, and 487 covers more breadth CO 481 - quantum algorithms (crosslisted with CS 467/PHYS 467) This is not an …”
About cryptography co-ops! 2 points, 2 comments
“I am an ug math student majoring in pure math and combinatorics/optimization at Waterloo. Are there any research opportunities in Waterloo on cryptography, mainly with David Jao. …”
u/Solid_Phrase: “He's also teaching CO 485 this term. Maybe you want to sit in his class go talk to him afterwards?”
Fall 2020
PSA: piazza has ads now 95 points, 19 comments
“smh is nothing sacred”
u/tendstofortytwo: “Fuck Piazza. One of my courses has been using Campuswire and it's been awesome. I hope more courses switch to using it soon.”
u/Spencer_Wilson: “CO 485?”
People losing their minds in CO330 after no updates from Prof for 2 weeks 532 points, 31 comments
u/femaths: “All of the CO courses this semester are jokes. For my CO course, the prof didn’t even post the assignment until Monday. It’s worth 20%, it’s fucking programming, and I’ve had 4 days to do it. …”
u/Spencer_Wilson: “Also David Jao's CO 485.”
CO 485 Grading Scheme? 2 points, 0 comments
u/puzzle_me: “For anyone that's enrolled in CO 485, I was wondering what the grading scheme this term looks like. Considering swapping into the course but not sure right now.”
Synchronous Lectures 73 points, 11 comments
“Just wanted to give a shout out to my three professors who decided to schedule their lectures at the same time and strongly recommend I attend the synchronous sections! …”
u/DrSeafood: “how is this even possible lol?? Did the profs just make up some other meeting times outside the scheduled timeslot? That sounds incredibly irresponsible”
u/djao: “… I have synchronous lectures for CO 485 and I was unable to find a 100% conflict-free time so I just picked the least conflicting time and will hope for the best.”
Fall 2019
PMATH 334 + 336 vs 345 + 346 vs 347 4 points, 9 comments
u/baktix: “I have a really big love for cryptography and want to take CO 485 at some point. While looking at the prereqs, I noticed any of the above 5 courses will do. From what I've gathered, 334 and 336 are "baby" versions of the content in 347. …”
CO 485 sample midterm 3 points, 0 comments
u/standardtrickyness1: “Does anyone have old sample midterms for CO 485 public-key cryptography?”
Spring 2019
Has anyone taken CO 485? 18 points, 0 comments
u/wandering_illusion: “Just wanted to know your experience with the course. I couldn't find much info about it. Mostly interested in knowing how interesting is the content and how hard it was.”
Spring 2018
Any math elective recommendations? 3 points, 7 comments
“I'm in need of a fifth course to enroll into for next term- can anyone recommend a math course that does not have ridiculous workload (I already have all my non-math credits)? …”
u/lippyrogue: “CO 485. Assignment+take-home midterm+ Final when I took it. There are like 5 assignments and all of them are short and easy (compared to other math courses)”
Interested in getting into cyber security field, is the math co-op program going to open opportunities for me? 3 points, 11 comments
“Title says it all, applied and got into math co-op. I feel like a math degree would be applicable to this field but I'm not too sure.”
u/Gibstick: “You can get a CS minor and take math crypto courses”
u/Gibstick: “CO 485, CO 487, and all of the CS minor-level courses that aren't "business" focused. CO 485 has nontrivial prerequisites.”
Winter 2018
Admissions Megathread (Fall 2018 Incoming Students) 57 points, 466 comments
“Hello UW applicants, This thread is specifically for those who are applying/applied to UW to discuss different admission issues and ask current UW students for help and advice. …”
u/r_a_m_e_n: “I'm in grade 11 this year so frankly, I have a while but I might as well ask sooner than later. If I want to go into cryptography, what should I apply to: math or computer science? …”
u/RogueBaneling: “Most of the cryptography courses are graduate-level, there are some introductory courses like CO487 & CO485 that you can take regardless of whether you are a CS or math student. I will say, it is easy to transfer from CS to math but not easy to transfer the other way. …”
Check it elsewhere for Fall 2026
- Undergraduate Calendar, 2026–27The official entry
- Requirements for Fall 2026Waterloo’s requisite checker
- Schedule of Classes, Fall 2026Instructors, rooms, live seats
- Quest Class SearchWhere you enrol
- Course outlinesSyllabi from past terms (UW login)
- UW FlowStudent ratings and reviews
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