Very interesting facts about number theory, the base of Cryptography. Although I'm mathematician, I've learnt new important facts in this course (especially those that refer to history or computation, including algorithms like trial division, Miller Rabin and RSA).

However, a couple mistakes were found in the correct answers of the graded assessments.

In my opinion, the slides are nice, but not enough. There should be a formal document to explain in more detail and more rigorously each step of the mathematical procedures, since several of them cannot be explained in a video or in a slide.

Also, the assessment should include more mathematical and programming exercises to put in practice the things we've learnt through the course.

To conclude, very nice and indispensable content, but not as excellent and well prepared as in the first course lessons.

This is one of the worse courses I've taken on Coursera. It seems almost abandoned. The additional material linked are simply wikipedia pages and the video lectures simply talk through the subjects with very little explanation or examples. You end up scrubbing through the videos to find the two seconds that you need to answer quiz questions. I found myself using external resources so much to answer questions that I had that it made this course almost useless. Many of the quiz questions are unnecessarily tedious. I need to understand the algorithm not prove that I can do arithmetic that will always be a fraction of the speed of a computer.

The instructor goes through content too fast. Not enough practices are given before the assignment. Overall quality is not ideal for the new learner.

I love the way that this course presents the basic group theory and number theory concepts central to so much cryptography. For example, I've tried to teach myself about the the Chinese Remainder Theorem and its use through my own self-study, but never really grokked it until this course. The same is true of primality testing.

The lectures really are outstanding, and the practice and graded assessments are extremely well constructed to help one get a real sense of what the theorems and algorithms do. The numbers in many of the problems are chosen to make certain things clear if you do those problems "by hand".

My only criticisms are not about substance, and are things that may not apply to your sessions or have been addressed by the time you are reading this. There were some errors in the early problem sets, the course slides are distributed at powerpoint only (and not PDF), and during my session there was virtually no interaction with staff or fellow students on the forums. These are minor issues, probably specific to the session I was in, but in combination are why I'm rating this four stars instead of five.

It is hard for me to assess how accessible this course is for most of the people who might take it. I found it "easy", but I've been doing self-study of this sort of stuff for a while. I also think that this is a "what you get out of it depends on what you put into it" sort of things. I got a lot out of it, but that is because I did the exercises both by hand, and then also wrote code to solve those same sorts of problems with bigger numbers.

To whom it may concern,

I love cryptography since it is an interesting subject. I enrolled for this course seeking from basics. but some concepts were not explained well. So I had to refer other materials as well. Hope it would be better if perhaps the explanations were simple and broad with more examples.

Thank you.

Go check your e-mail. You’ll notice that the webpage address starts with “https://”. The “s” at the end stands for “secure” meaning that a process called SSL is being used to encode the contents of your inbox and prevent people from hacking your account. The heart of SSL – as well as pretty much every other computer security or encoding system – is something called a public key encryption scheme. The first article below describes how a public key encryption scheme works, and the second explains the mathematics behind it: prime numbers and mod n arithmetic

Helped me a lot, i was using several algorithms without knowing the math behind them, know i understand a little more thanks to the course, thanks guys

I strongly recommend doing the 3rd and 4th course first in this series to get a bit more solid mathematical foundation if you have none. Additionally, Google the terms and watch YouTube clips for simpler explanations instead of just listening to the chapters.

Good course - but could do with worked examples of the math problems and some problem sets to practice with. This course told me what to learn and related it to crypto but I had to go to youtube to actually learn the math

This course very good for beginners, but the drawback is that explanation by the mentors are not good enough to understand completely.

The teaching was not at all good, he was just reading it.

Es magnifico reibir cursos de gran calida y super interesantes, me parecio de enriquesedor, me gustaria seguir recibiendolos

It was an awesome course, I found the idea of cryptography deeply. After 10 years I fullfilled one of my dream.

Great course for Cryptography beginners. Well explained topics and good implementation based quizzes.

Very interesant course. A very practical approach to modular arithmetics.

Lessons are OK, but you need to watch in x1.25-x1.5 speed, to be honest. There were quite a few errors in quizzes, that made general impression worth.

This course does a really nice job introducing you to the basics of math for cryptography and at the same time getting a broad understanding of how the concepts apply to real life. As a complete beginner to this topics, this course was really interesting and useful

I found this course very challenging which I enjoyed. Zillion thanks to lecturer William Bahn for opening my eyes in how Mathematics needed in Cryptography. I will do more practices and practices in this new skill.

I enrolled for this course because Number Theory is my area of interest. This course has helped me to spend my time effectively during this lockdown period. Thank you Coursera.

Very interesting course which is starting to be challenging to the occasional student and throws the basis for real comprehnsion of facts always accepet as true.