Lecture 7: Introduction to Galois Fields for the AES by Christof Paar

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  • Опубликовано: 29 янв 2014
  • For slides, a problem set and more on learning cryptography, visit www.crypto-textbook.com

Комментарии • 287

  • @Qbabxtra
    @Qbabxtra 7 лет назад +353

    Such shame he has to tell his students to be quiet and pay attention. This lecturer is brilliant! 10x better than ours.

    • @bonbonpony
      @bonbonpony 7 лет назад +6

      Yeah... here where I live he could simply smack them through their heads or kick off the classroom :q

    • @Falaxuper
      @Falaxuper 6 лет назад +4

      Yeah, the students are fucking dickheads

    • @beckychiang2667
      @beckychiang2667 5 лет назад +8

      Had I had a teacher like Prof. Paar, I would have absolutely devoted to my study.

    • @maxinator80ify
      @maxinator80ify 5 лет назад +7

      Normally it's really quiet compared to other lectures, however sometimes a few people talk and he will immediately call them out.

    • @amynguy
      @amynguy 4 года назад +11

      students are propably also discussing the course material.It happens

  • @Josearnaldomanuel2
    @Josearnaldomanuel2 5 лет назад +45

    So many times he has to ask for students to be quiet.
    His students should appreciate this subject, he's really good. We don't even have this subject in my alma mater.

  • @dpraajz
    @dpraajz 4 года назад +84

    4:45 Intro to Finite Fields (Galois Field)
    29:20 Prime Fields (GF(p))
    44:20 Extension Fields (GF(p^m))

  • @peterosudar1636
    @peterosudar1636 7 лет назад +35

    At 17:00 "Don't work through chapter four by yourself". Wiser words never, ever spoken.

  • @gototcm
    @gototcm 9 лет назад +175

    This Prof who I suspect has a native language of German is more coherent than most native English Profs in the USA. Excellent course

    • @chrism7574
      @chrism7574 4 года назад +3

      That's simply not true. I don't even know why you'd think that.
      He has better English than some foreign professors, but not American professors. That's simply because English is very common in Germany.

    • @rumpelstilzchen4202
      @rumpelstilzchen4202 4 года назад +27

      @@chrism7574 He's not talking about the Quality of the English, but about the coherency of it. You can have excellent well spoken english but still fail at actually teaching with it.

    • @arekkrolak6320
      @arekkrolak6320 3 года назад

      This guy is unable to make two sentences together without throwing in a word in German

    • @majormalachi1901
      @majormalachi1901 3 года назад

      dunno if anyone gives a shit but if you are stoned like me atm you can stream all of the new series on instaflixxer. Have been streaming with my gf during the lockdown =)

    • @prestonamir3585
      @prestonamir3585 3 года назад

      @Major Malachi Yup, have been watching on InstaFlixxer for since december myself =)

  • @CryingMG
    @CryingMG 3 года назад +10

    If only i could've studied in your university. Im pretty sure all professors are absolutely top notch. Having to tell people to not talk during the lecture is .... just... i don't even know. Lecture is so so interesting, so brilliant, would've been drowning myself in coffee and listening with both my ears. Much thanks for your work professor.

  • @omarespino964
    @omarespino964 Год назад +5

    Prof. Paar NOTHING boring about your class. You are a great and excellent teacher. THANK YOU for all the videos of your class It has sparked my interest and passion for cryptography. Best wishes for you and family. You don't have to worry about me sleeping in your class. I'm ALWAYS AWAKE!

  • @nwildner
    @nwildner 7 лет назад +66

    Came here to learn about AES, and learned a lot of Math. Not disappointed :). Thumbs up for your lecture.

    • @bonbonpony
      @bonbonpony 7 лет назад +8

      It was the opposite for me: I came here to learn about Galois fields, and I learnt how the AES internals really work as a bonus :) (to this day, I only knew how to do the computations by using precalculated "multiplication tables" - now I can conjure up those tables myself :) )

  • @jiaxian7470
    @jiaxian7470 4 года назад +3

    Thank you Prof Paar for making a whole lecture series on cryptography. Your explanation is super clear and easy to understand. This is saving me a lot of hours reading my textbook.

  • @chaithanyaks5425
    @chaithanyaks5425 5 лет назад +16

    This was an absolutely brilliant lecture. I had been trying to understand the galois theory used in AES for a while and this lecture just saved me. Thank you so much.

    • @taopaille-paille4992
      @taopaille-paille4992 4 года назад +1

      this is not galois theory. galois theory is a different beast and a branch of maths. what he did is presenting the basic arithmetic properties of GF(2^m), which are sometimes called Galois fields

  • @muppalaneninitin
    @muppalaneninitin 5 лет назад +1

    Thank you so much for putting your course online, Prof. Paar. You are an outstanding teacher. I just ordered your book and eagerly waiting for it to be delivered.

  • @avrelyy
    @avrelyy 10 лет назад +20

    Best(easiest) explanation for fields I have ever heard! Thanks!

  • @vincentvegas899
    @vincentvegas899 8 лет назад +7

    Much better than my professor. Going to continue watching the series Prof. Paar. Thanks for uploading.

  • @harirao12345
    @harirao12345 5 лет назад +1

    Extraordinary! A very complex theory handled in a very logical way in just 90 minutes. Thank you 🙏

  • @JYGamerDad
    @JYGamerDad 8 лет назад +2

    Thank you, this lecture was really helpful. I am giving a short presentation in class on Reed Solomon codes, but didn't fully understand Galois fields, and this helped tremendously!

  • @nerojrnde
    @nerojrnde 8 лет назад

    Really good supplement to my course at school that uses your book. Thank you for making these videos.

  • @muhammadumair3992
    @muhammadumair3992 5 лет назад +2

    Such an interesting lecture. Came here to get a basic idea on finite field, but stayed on till the end. It is almost the end of my Semester at Unimleb (Course: Crypto) and I have an exam next week but it was only until today that I was really able to understand a lot more than what I wanted to know. Thanks, Professor Paar (many thumbs up).

  • @HDjonnern
    @HDjonnern 6 лет назад +1

    Excellent explanation of GF, groups and rings. And I finally understand the reason for the "AES polynomial".

  • @messpilo
    @messpilo 7 лет назад +1

    thank you very much. Clear presentation . I always look for clear explanations to watch and your presentation is very clear .

  • @rohitrohra8828
    @rohitrohra8828 6 лет назад +1

    A brilliant brilliant explanation ....thank you so much. Teachers like you are the reason why education is so much fun and interesting. Otherwise the teachers in universities like mumbai university make the students hate the subject so that they have to put less efforts in classrooms .

  • @nick9198
    @nick9198 5 лет назад +2

    This guy is awesome. Wish all my lecturers were like this guy.

  • @Karim-nq1be
    @Karim-nq1be Год назад

    Very good lecture. I don't get how someone would fall asleep by hearing about Galois Fields for the first time, it's so fascinating.

  • @aok9969
    @aok9969 2 года назад

    Excellent lecture. Highly proficient lecturer. Would recommend this lecture series to almost anyone.

  • @mr.shanegao
    @mr.shanegao 3 года назад +6

    Motivation AES 2:00
    intro FF 5:00
    prime field arithmetic 30:00
    extension field arithmetic 45:00

  • @markbordelon1601
    @markbordelon1601 3 года назад

    ich moeche darauf hinweisen, dass ich, waehrend der youtube-lektion, wirklich nicht geredet habe! :-) Aber ernsthaft: wie viele anderen hier kommentierten, haben Sie auch mich endlich ueber das Mysterium Galois Fields verklaert. Vielen Dank, Herr Paar! Sie verdeinen Respekt!

  • @TanmayDasiitp
    @TanmayDasiitp 6 лет назад +1

    Good explanations ! I liked the way you teach, looking forward to your other videos.

  • @kyllobrooks8928
    @kyllobrooks8928 Год назад

    This material is exceptional and has helped me study for a undergrad fourth year course in cryptography.

  • @gototcm
    @gototcm 6 лет назад +4

    Great teacher. I'd get a PhD if this guy was my advisor.

  • @viorelspinu
    @viorelspinu 8 лет назад +2

    Great course, very well explained, a lot of useful info. Thanks a lot!

  • @ashayshirwadkar
    @ashayshirwadkar 6 лет назад +1

    Wow.. it's really amazing as well as interesting Introduction to Galois Fields (which was helpful to understand mathematics involved behind RAID 6 as well.)

  • @dailygrowth7967
    @dailygrowth7967 Год назад

    Wow - i am so glad i found this lecture. Danke Professor Paar!

  • @kthwkr
    @kthwkr 4 года назад

    Good lecturer. Well organized presentation. Good video production. Good audio.
    Easy to read the chalk board.
    I wish all the class room videos could be this good.
    This should be the example of the industry standard for filming a classroom lecture.
    I have watched the entire series and I am pleased that the mystery of encryption is gone from my mind.
    I've tried to watch other lecture series but disappointed that the production was not as good as this one.

  • @dechicken
    @dechicken 7 лет назад +6

    Awwww I want to learn about division! Damn lazy stupid undergrads! You guys were lucky to have this professor.

  • @Olivia-jx5pw
    @Olivia-jx5pw 6 лет назад +1

    Thank you so much your a life saver. I really enjoyed your lecture, it helped me allot in understanding the mix columns step in AES

  • @liukaiyu683
    @liukaiyu683 3 года назад +1

    Legendary resource on RUclips, Thanks Prof!

  • @kindoblue
    @kindoblue 9 лет назад +1

    Enjoyed the lesson. Excellent work. Thanks Prof. Paar

  • @odgreat
    @odgreat 10 лет назад +1

    Excellent lecture !
    Just what I needed to fill in the missing gaps in my understanding of AES.
    Tried to understand the material from several sources, but nowhere was it as clear as the professor explains in this video.
    Worth the 90 minutes spent.

    • @bonbonpony
      @bonbonpony 7 лет назад

      Fun fact: this can also help you understand CRC (Cyclic Redundancy Check) checksums as a bonus :)
      (AES could be thought of as a glorified version of a CRC)

  • @Queen_Popsicle
    @Queen_Popsicle 9 лет назад

    My current professor has great understanding, but lacks the ability to communicate the concepts well. Thank you so much for laying out these tough topics in a way that is easy to understand!

  • @shumymikaball
    @shumymikaball 5 лет назад +4

    That board cleaning was relaxing.

  • @udaydungarwal1072
    @udaydungarwal1072 8 лет назад +4

    Superb explanation.. will follow for the full semester !!

  • @huyanh995
    @huyanh995 6 лет назад +2

    Thank you so much. Your lecture helped me a lot to my final exam in next week :D

  • @EmekaI
    @EmekaI 4 года назад +1

    Thanks all the way from Cambridge University. I missed my last lecture but this definitely makes up for it!

  • @suryasikharej8116
    @suryasikharej8116 6 лет назад

    had a tough time understanding....but wow this lecture is so good...now my concepts are crystal clear ...i have exams next week thanks sir...respect

  • @TheDreams0000
    @TheDreams0000 8 лет назад +1

    thank you so much ....you finished one of my chapters in 90 minutes

  • @kingsleyokoli3986
    @kingsleyokoli3986 Год назад

    Interesting lecture. Prof Paar did a lot of work in there! Thank you

  • @nordvpnnordvpn
    @nordvpnnordvpn Год назад

    Man today I just chosed my subject for my presentation about different algorithms and I drawn "finite fields and it's appliance in cryptography" and since 4 hours I am sitting listening and reading about them and I was so angry at the beginning that I had such hard topic but now I feel really entertained lol I wish I had a teacher like you in my univeristy. Greets

  • @NikitaSilin
    @NikitaSilin 10 лет назад +1

    I would hit "thumb up" 1000 times if I could. Thank you very much, it was very helpful!

  • @Farhanali-kq2wj
    @Farhanali-kq2wj 3 года назад

    Such a great lecture. Thank you very much for uploading

  • @mintmao6142
    @mintmao6142 6 лет назад +1

    Thank you Prof! Thank you very much for your brilliant lecture! :)

  • @user-zy3kd4xj7z
    @user-zy3kd4xj7z Год назад

    Can't believe this is a uni lecture. Last time I heard ''be quiet'' and 'dont fall asleep 'was in high school😵‍💫

  • @mariaisabelmartinezcastill4438
    @mariaisabelmartinezcastill4438 4 года назад +10

    I'm in high school and I find these fascinating such a shame that he has to ask his students to shut up

  • @user-kc7gm9ty5o
    @user-kc7gm9ty5o 4 месяца назад

    Thank you for this wonderful lecture, Mr. Paar.

  • @ClydeDCruz_zurCDedylC
    @ClydeDCruz_zurCDedylC 5 лет назад

    Thank you! Wonderful teaching!

  • @2019RS3
    @2019RS3 7 лет назад

    Thank you Dr. Parr, I'm not joking when I say you saved my buttocks. I am using the same book in my Crypto course but was baffled by how exactly reduction takes place after my professor's explanation. I watched your course from start to finish, took notes, and now I understand. Thank you! Now, on to the Extended Euclidean Algorithm. Thank you again Dr. Pharr, this was an excellent lecture.

  • @GuoFuTseng
    @GuoFuTseng 3 года назад

    Very helpful course! Big thanks for sharing.

  • @FelipeMontealegreS
    @FelipeMontealegreS 8 месяцев назад +1

    This man is an American hero

  • @rasb421
    @rasb421 3 года назад

    Awesome lecture. Students are gifted

  • @goebbelsx
    @goebbelsx 9 лет назад +2

    Excelent!! Thank you profesor.

  • @hevalderishky9696
    @hevalderishky9696 8 лет назад

    Hello... Dr. Christof Paar ...Thank you so much i leaston you lucture on the You Tube its very Good..

  • @Tristoo
    @Tristoo 3 года назад +1

    Ironic that I skip all my actual classes but then spend hours watching stuff like this at home. Thank you for this and great job.

    • @dailygrowth7967
      @dailygrowth7967 Год назад

      I do this too. i actually feel like i can learn better in my comfortable home space. What do you think is the reason why you do that?

    • @dailygrowth7967
      @dailygrowth7967 Год назад

      Also, not all lecturers are as good as the ones found on RUclips. There are lectures by legends in some fields (think Reinforcement Learning by Dr. David Silver)

  • @hojiayi
    @hojiayi 8 лет назад +16

    lol @ those two students fighting when he's cleaning the board

    • @beback_
      @beback_ 6 лет назад

      When was that?

    • @arij843
      @arij843 6 лет назад +1

      At around 59:00

  • @RahulChauhanart
    @RahulChauhanart 8 лет назад +1

    Thanks prof. paar for the lecture :)

  • @abhijithrangudu4383
    @abhijithrangudu4383 6 лет назад +1

    The video was really very helpful. We would love to listen about the irreducible polynomials p(x) from you immediately after the term is introduced in lecture-4 as primitive polynomial

  • @startreck9204
    @startreck9204 2 года назад

    Thank you for the book and the lectures!

  • @samgregg7
    @samgregg7 7 лет назад

    Fantastic lecture, thanks very much.

  • @pratikshethcool
    @pratikshethcool 10 лет назад +5

    Way better than my professor...!

  • @beback_
    @beback_ 7 лет назад

    Amazing that junior undergrads get to learn this. So jealous of these kids!

  • @Mahdi-jd7kk
    @Mahdi-jd7kk 6 лет назад

    Excellent course, thanks.

  • @lamasleem7569
    @lamasleem7569 7 лет назад

    great great great explanation. Thank you

  • @davelloyd-
    @davelloyd- 5 лет назад

    This REALLY helped. thank you so much

  • @piyushsuthar9088
    @piyushsuthar9088 4 года назад +1

    Really helped a lot.thanks professor...

  • @azagogh
    @azagogh 10 месяцев назад

    A pleasure to watch, ty.

  • @plushiie_
    @plushiie_ 3 года назад

    Love it when he talks about his past :D

  • @krishnaMurari48
    @krishnaMurari48 8 лет назад

    cleared all my doubts about finite fields . danke

  • @__noob__coder__
    @__noob__coder__ 5 месяцев назад

    Thanks professor for this amazing lecture !

  • @1mursyid1
    @1mursyid1 3 года назад

    Thank you prof, learnt tons!

  • @TheBSpaZZ
    @TheBSpaZZ 5 лет назад

    Wonderful lecture. Thank you.

  • @T-She-Go
    @T-She-Go 4 года назад

    Wow. Thank you so much. You just helped me to connect the dots :D

  • @zee1598
    @zee1598 2 года назад

    Best lesson on encryption ever.

  • @indrakumari1854
    @indrakumari1854 8 лет назад

    Thank you sir ....great lecture

  • @ghffrsfygdhfjkjiysdz
    @ghffrsfygdhfjkjiysdz 9 лет назад +1

    Thank you for a good and interesting lecture. One suggestion and one question. Suggestion: when discussing Galois say from the beginning that the definition is applicable to modular math. It feels like a cheap-shot to just bring it up at the end, with the buildup having viewer puzzled how the fields could possibly work in non-modular math. The question is this: in modular math with numbers the size of the set was used for modulation (mod2 for 0 and 1; modP for 0,1,2...P-1) What is the justification to be using a prime polynomial rather that a set size with polynomial modulation? Or perhaps the Largest polynomial+1, so for 3-bit case would be X^2+X+1+1=X^2+X? Thanks again for interesting lecture.

  • @defenderwahlang5684
    @defenderwahlang5684 Год назад

    Such an amazing explanation, in india professor makes things complicated

  • @SalvatoreCao219
    @SalvatoreCao219 7 лет назад

    Thank you for the super video.

  • @mohsennoor
    @mohsennoor 10 лет назад

    Thanks.
    perfect teacher

  • @fionarozario
    @fionarozario 8 лет назад +1

    Thank you, so much!

  • @leemerlin7537
    @leemerlin7537 5 лет назад

    very clear, thank you so much

  • @shankarsamrath2259
    @shankarsamrath2259 2 года назад

    Thank u so much prof for lecture, it was really amazing

  • @mahsailaghi5554
    @mahsailaghi5554 5 лет назад

    Perfect . you helped me so much...

  • @yusufmohamedsalh8321
    @yusufmohamedsalh8321 8 лет назад

    I loved your lecture ,sir ,Thanks a lot. I am trying to guess the words in German would be "Don't speak for the video" or similar ,Also you made me enjoy cryptography a lot,once again Thanks Prof.Paar :D .

  • @vijayakumark5190
    @vijayakumark5190 7 лет назад

    Thank you professor!

  • @hishamalshaheen750
    @hishamalshaheen750 8 лет назад

    Thank you so much for the lecture. I have one question please. How can compute the coefficients from GF(2^8) and compute the inverse of the coefficient?

  • @psy0rz
    @psy0rz 4 года назад

    Started with 8 and now going to learn about this Galois magic.

    • @zoranhacker
      @zoranhacker 4 года назад +1

      same, just finished this one but I think I'm off to Lec. 11 now, down the rabbit hole we go!

  • @tavrion
    @tavrion 2 года назад

    Wonderful explanation of GF(p^n), thank you

  • @user-ml6qs4zk8z
    @user-ml6qs4zk8z Месяц назад

    Thanks for the great explanation since I am looking for the answer about AES GCM message authentication ❤

  • @andrewalaniz6656
    @andrewalaniz6656 7 лет назад +8

    When you draw the diagram of the structures in the beginning, you should draw the groups as the largest circle, and as you add structure/operations it makes the set of elements smaller and smaller i.e. all fields are rings and all rings are groups. The way you draw it makes it seems like all groups and rings are fields, which is nonsense. Very interesting though:)

    • @introductiontocryptography4223
      @introductiontocryptography4223  7 лет назад +16

      I see your point and that could actually help some students. On the other hand, I always pictured the structured as follows: every ring contains a group and every field contains a ring and groups. Thus, I am not sure what the best approach is pedagogically speaking. Thanks for your thoughts, though. christof

    • @bonbonpony
      @bonbonpony 7 лет назад

      If that was the case, then the diagram should have contained two instances of the group ;) (one for addition, the other one for multiplication), pretty much sharing the common set (except 0 being excluded from the multiplicative group's set).
      Another possible way to draw it that could be more intuitive to IT engineers could be to use an inheritance diagram similar to those used in programming languages like C++ or Java ;)

    •  5 лет назад

      Totally agree!

    • @nannimmamvong2741
      @nannimmamvong2741 5 лет назад

      ​@@introductiontocryptography4223 , in addition to your point, making the group the largest circle might also defy the fact that the group is defined by only one operation. Because you will end up having all the other operations contained in the bigger circle which represents a group. I therefore agree more with your own structure. Thanks a lot for this brilliant lecture.

  • @shashankbj3804
    @shashankbj3804 2 года назад

    Thank you very much Professor..

  • @test1test2-zv3xn
    @test1test2-zv3xn 5 месяцев назад

    Thank you for the lecture

  • @fredrik4876
    @fredrik4876 3 года назад +1

    Excellent lecture! You even get help to develop an intuition for finite fields. Only someone with deep knowledge can make something this difficult seem simple. Recommend watching the lecture in x1.5 speed.

  • @suneel1942
    @suneel1942 5 лет назад

    Sir it's excellent explanation. Can you share how to find multiplicative inverse of a number in GF2,8

  • @futurDaFutur
    @futurDaFutur 9 лет назад

    Thank you so much !!!