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Learner Reviews & Feedback for Cryptography I by Stanford University

4,239 ratings

About the Course

Cryptography is an indispensable tool for protecting information in computer systems. In this course you will learn the inner workings of cryptographic systems and how to correctly use them in real-world applications. The course begins with a detailed discussion of how two parties who have a shared secret key can communicate securely when a powerful adversary eavesdrops and tampers with traffic. We will examine many deployed protocols and analyze mistakes in existing systems. The second half of the course discusses public-key techniques that let two parties generate a shared secret key. Throughout the course participants will be exposed to many exciting open problems in the field and work on fun (optional) programming projects. In a second course (Crypto II) we will cover more advanced cryptographic tasks such as zero-knowledge, privacy mechanisms, and other forms of encryption....

Top reviews


Jan 13, 2020

Provides a comprehensive introduction to cryptographic history, current technology, best practices and known attacker techniques. A great deal of material is covered in a relatively compact program.


Dec 15, 2017

This course gives is perfect to start learning cryptography, explanations are detailed, topics carefully selected combining theory with real world examples and making emphasis in important details.

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51 - 75 of 875 Reviews for Cryptography I

By Preet D

Jan 8, 2022

The Course instructor is good no doubt but the main quandary I faced was it went from 0 to 100 to expeditious what I betoken is that at start the fundamentals was thought but suddenly the caliber of course went very advance and that led me to leave this course incomplete


Oct 28, 2021

For me there is no benefits from this course.

Same explanation and same slides, when I was in college.

By Ryan T

May 27, 2020

This course does an excellent job of explaining the fundamentals of cryptography and showing real-life applications built on these constructions. Moreover, it provides the student with useful abstractions and frameworks for evaluating the security of cryptographic constructions. What I really enjoyed about this course was getting my hands dirty with some of the programming exercises. Each week has a programming exercise, some of which give you an opportunity to leverage well-known vulnerabilities to mount attacks on various cryptographic constructions.

I gained a deep appreciation for the science, as well as the art, of cryptography from this course. I'm excited to learn more in the second course this fall to expand upon the concepts introduced in this course.

One thing that I think is worth mentioning, however, is that you should really expect this course to take up around 10-15 hours of your time per week (depending on your commitment and speed with completing the programming exercises). The course material is very dense, and there are some mathematical concepts later in the course that may take you some time to wrap your head around if you are unfamiliar with or haven't had recent exposure to them. I say this because Coursera provides its own estimates for each part of the course (lecture, quiz, programming exercise), but you should know that these are completely inaccurate. The lecture videos are rich with content and move very quickly, so you will need to pause them frequently to catch up on notes and absorb the concepts.

By Istvan S

Sep 4, 2017

This is a fabulous course. Professor Boneh did an admirable job teaching the basics of modern Cryptography. Modern Cryptography was born at Stanford University founded by Martin Hellman and two students. It used at first intuitive ideas linking complexity theory to cryptography. The old cryptography, that is cryptography at around the Second World War was a a rigorous theory based on Information Theory and founded by Claude Shannon. Modern cryptography was based on the idea that if a cryptographic system cannot be broken in billions of years, then it is for all practical purposes just as secure as a theoretically unbreakable system. In the last 30 years or so the proper definitions were found to make this intuitive idea precise, making modern cryptography a rigorous science. Professor Boneh presents this rigorous theory in this course.

By Yuval G

Nov 9, 2016

The course is very interesting and very challenging,

As an firmware engineer who never had the chance to learn Crypto. the course gave me a grate introduction to this field.

It is very fascinating to understand the different Crypto. methods and their vulnerabilities, and it made me more aware and gave me the ability to evaluate strength of Crypto. systems that I encounter.

Before every topic there were a detailed overview on the Math theory required to learn it, the explanations followed by real life examples and it feels like the team put a lot of effort to make the lectures comfortable and easy to follow.

The Homework are challenging and very help-hull to understand the learned topics.

By Advaith G

Aug 24, 2020

I took this course right before starting my undergraduate degree in Computer Science. While I would agree that the level of difficulty was high, and the mathematics was very detailed, I can honestly say that the professor does a very good job explaining it. I took detailed notes from the beginning and reading the references combined with paying attention to the lectures really helped me understand the concepts really well. The problem sets were amazing and tested a thorough understanding of the topics which made them very fun to solve. I would recommend this course for anyone looking to get into cryptography who doesn't mind putting a lot of effort into learning the basics of the field.

By Gregory V

Nov 13, 2017

Outstanding coverage, very fast paced.

I enrolled in this course to gain an understanding of cryptography beyond material designed for the consumption of the non-technical audience. The lectures by Prof. Boheh were very clear and well organized, with emphasis on fundamental definitions. The section on basic number theory was most helpful. While taking the course, I was also learning the Python programming language, so I attempted most of the optional programming assignments in Python. This reinforced the material a great deal. I will recomment this course highly and will definitely enroll in Cryptography II when it becomes available.

Thank you for a great learning experience.

By Nastassia M

Dec 7, 2019

Amazing course! Enjoyed it so much! Many thanks to Professor Dan Boneh.

Although the lectures are quite short they contain a lot of useful information. You might want to watch them more then once!

The quizzes are designed in such a way that you have to understand the material in order to pass them - just memorizing won't be enough. That's a sign of high quality.

Don't skip the practice quizzes - they are challenging, thought-provoking and help you understand the topic much better.

Bear in mind that the course requires certain math background in discrete probability and number theory. You'll find some books recommended to fill in the gaps at the beginning of the course.

By Maxim B

Feb 19, 2020

That was the hardest thing i've ever learned in my whole life, but I'm well satisfied by this course. Thank's to this course I finally understood the way I have to use crypto without risk of being hacked because of simple mistake I made. I also wanna say THANK YOU SO MUCH! to professor Dan Boneh for the best possible explanation of the course's material and THANK YOU SO MUCH! to Coursera for giving me an opportunity to learn this high quality educational material while being in the middle of nowhere. Sometimes there were a tiny problems with sound, but it's not critical. Anyway, it's much better then the education that I could get in my region.

By Wolfgang G

Mar 8, 2018

Very interesting and intense course, covers probably more than twice as much material as some other courses in the same time. The lecturer Dan Boneh is very motivated and very competent. It makes a significant difference listening to someone who is an expert than just reading a book about it. That said, having a textbook in addition to the videos is a great help, as it gives you a different perspective, which helps a lot with understanding. The questions and programming exercises are interesting and challenging (unfortunately I did not have the time to do the coding exercises), though some of the questions could be formulated a bit clearer.

By Aryanadi I C

Dec 4, 2021

It's been such a wonderful leaning curve for me to learn and study Cryptography from Prof. Dan Boneh. I came from zero background and skill in Cybersecurity so I really had no clues what Cryptography was when I enthusiastically enrolled in this course until I listened to the What is Cryptography video lecture. One thing for sure, I will continue studying and exploring Cryptography algorithm and I hope the certificate I've just received can always be a kick-start my new life goal in becoming Cryptographer & Cybersecurity expert. I'll do my best. Thank you, Prof. Dan Boneh for this enlightenment for me.

By Jens N

Jul 29, 2017

Very good introduction for someone who wants to understand cryptography at a level deeper than "This is the Crypto API". After the course it is not only clear "what to (not) do" but also "why". Some mathematical understanding is required (I'd say university entry level).

The pace is just right. The questions dispersed throughout the lectures really help the process of understanding because they force to think about the problem at hand. Also very good is that each session starts with a short summary of the last session. Very helpful, if you watch this course in the evening after a workday.

By shreyash m m

Mar 30, 2021

This was a really great course, being an undergrad it felt a bit dense but still doable, the mathematical discussion was just enough so it won't scare away a computer engineer but won't piss off a mathematician, However at certain times I felt that I was loosing track of what's happening in the grand scheme. The optional programming assignments were probably the most fun past of the course, don't skip them!!, even if you don't know how to code, quickly take up a simple language like python. Overall a great introduction to the subject, can't wait for the follow up crypto 2 course.

By Deleted A

Feb 4, 2020

Really good course. The professor knows what he is talking about and he explains as easy to understand as possible. As engineer it was sometimes difficult but not impossible for me to understand everything right away.

The only thing in my opinion that could make the course way more understandable are step by step examples with real numbers/text/messages. The examples in the course are good but too general to understand without a strong mathematical background.

I would recommend this course and I would say it is one of the best cryptography courses you'll find in internet.


By Ian K

Aug 16, 2020

A very thorough and rigorous course covering the primitives of modern cryptography. While all the math needed is included in the course, I highly recommend you have some kind of background in how mathematical proofs work, as the notation and ability to follow the logic of all the symbols can be overwhelming if you're new to them. Professor Boneh is excellent, and even a cursory internet search shows that he is highly regarded in his field. It was a privilege learning from someone so knowledgable, and I look forward to Cryptography II whenever it is released.

By Hasan K

Sep 18, 2021

One of the best courses I had so far. This course requires patience, a lot of thinking. It rewards you with great learning experience. This course encouraged me to go further into details of cryptography. I will still be reviewing my notes and what I learned from this course in coming months and enroll to the second course from Prof. Boneh. It definitely worth it. I also strongly recommend investing some more time into number theory (at least first four chapters of Viktor Shoup's book) to feel good about the theory of public key cryptography.

By Fabio T

May 25, 2023

I'm no more a student as I'm well over the mean age of a student, anyways I currently work in IT sector as a System Engineer and Cryptography as been always something similar to black magic to me :) This course was quite an experience and a opening eyes one! Professor Boneh even over a "cold" video has been able to communicate his strong passion for this field and I'm really grateful to him and Coursera for letting me have the opportunity to learn from such a valuable mentor.

I will always remember this course and the things I've learned.

By Marte M

Sep 21, 2016

I had to review college algebra and some of the prerequisite, optional material to get by. I found myself thinking I understood until I got to the quiz. There are a lot of spaces where he assumes you know things or that you will figure out that a+b=c (like putting 2 and 2 together). Notes should probably be taken in outline format. After watching a couple weeks you can tell how he organizes it. The teacher is very knowledgeable and explains concepts very well. The material can still be incredibly hard and gets easier as you repeat it.

By Yehor B

Oct 25, 2019

Extremely useful course that allowed me to get into computer security without any SUBJECT-SPECIFIC knowledge. Background in mathematics and programming definitely required to successfully complete the course, but if you have it, you can easily grasp concepts and constructions defining fundamental building blocks of modern computer security. I really hope that advanced course will land sometime, or at least extension of this one covering topics digital signatures, authenticated key-exchange and other good stuff.

By Sophie

Sep 22, 2019

Clearly structured, well explained first course on the subject.

At times it appears too thin as mathematical proofs are not detailed, but as the course goes on, references to further readings are included which allows a more advanced understanding of the subject ( in maths and computing). This allows for a rather large range of topics to be introduced. Well done and last but not least, thank you so much, Dan !

Note: The pace of the course is also flexible. This course is perfectly doable ( on top of any job).


Mar 15, 2021

Very interesting course, with the right balance between mathematical underlying considerations and practical implementation. There is a good progression and order of introduction of various crypto mechanisms. Explanations / demonstrations are clear (a bit quick though). Overall, the course is very dense and requires quite some side / review work. The quizz are well done and really allowed myself to identify the area that I didn't well understand in first pass. Thank you to Dan for this great course !

By Petr S

Jun 21, 2020

Great course, thank you!

This is a great introduction to Cryptography. Before this course, I was a complete beginner and now I am reasonably comfortable with the basics. I am definitely planning to take Cryptography II sometime in the near future.

One comment - working full time and taking this class was not easy. For future classes, it might be easier if you make each week less packed, possibly even splitting each week into 2 weeks. This would make it easier to keep up with the schedule.

By Athanasios M

Jul 6, 2020

This course is the Α and Ω about Cryptography and Security. It provides a very thorough overview of the basics of Cryptography from a theoretical point of view, albeit including including real life examples. Definitely recommended even for persons already familiar with cryptographic or security concepts. Professor Boneh is extremely illustrative and provides his expert knowledge in a very practical manner. I sincerely thank you for the amount of knowledge provided in this course!

By Markus S

Apr 5, 2017

This is a fantastic introduction to the world of cryptography! You learn about the basic concepts of encryption, authentication, authenticated encryption, public and private keys and the underlying mathematical principles that (should) make it hard to break the ciphers! You also learn about historical developments, real world applications and current challenges that would bring you instant fame in the crypto world. Also it is not a disadvantage if you really love solving puzzles!

By Piero C

Sep 13, 2017

I'm the Technical Director of an electronic company. I didn't know very much (certainly not enough) about cryptography, except some vague general information. My company needed to gain first hand knowledge to protect a new line of products, for which online reprogramming will be necessary. This crash course about cryptography has been extremely enlightening, to address the development of these procedures.

Thank you Dan for your good work and carry on with it.