The Mathematics of Cryptography

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  • เผยแพร่เมื่อ 23 พ.ย. 2024

ความคิดเห็น • 226

  • @zachstar
    @zachstar  5 ปีที่แล้ว +91

    Hope you guys enjoy! And here's part 2: th-cam.com/video/xmwxDHX6xUc/w-d-xo.html

    • @PKPS01238
      @PKPS01238 5 ปีที่แล้ว +1

      MajorPrep Hey MajorPrep, thanks for creating these videos, I’m a freshman CS major and am interested in cryptography, so these videos really help!

    • @dancepants3399
      @dancepants3399 5 ปีที่แล้ว

      i read a really good book called the code book all about cryptography. it also covers ciphers like rsa... you should read it

    • @Boss-3guru
      @Boss-3guru 2 ปีที่แล้ว +1

      Sir .. group theory in cryptography ma bi ya example LA saktay

    • @chinmayrath8494
      @chinmayrath8494 ปีที่แล้ว

      We did, thanks a lot

    • @johnsantavicca5016
      @johnsantavicca5016 6 หลายเดือนก่อน

      Do you get paid in cash to secretly do peoples homework? That is a tricky subject because I wouldn't learn. It's actually more like you get paid to tutor. Extra credit

  • @dragonrykr
    @dragonrykr 5 ปีที่แล้ว +775

    Khoor friends

    • @skylark.kraken
      @skylark.kraken 5 ปีที่แล้ว +21

      iulhqgv*

    • @kevin780313
      @kevin780313 4 ปีที่แล้ว +22

      khoor zruog!

    • @xofyu
      @xofyu 4 ปีที่แล้ว +7

      d564145aa1bae0255dc21dacfe33b258370b3c7cec44956af2d1366f5025a5ad

    • @evm6177
      @evm6177 3 ปีที่แล้ว +3

      Scifi talks about transferring thoughts through something like brain waves. Crypto to me is a step in the direction of future communication as it evolves. 🍷👄💬

    • @xxdxx3776
      @xxdxx3776 3 ปีที่แล้ว +1

      @@xofyu "friend" in SHA256

  • @jordancarpenter676
    @jordancarpenter676 4 ปีที่แล้ว +88

    Simon Singh wrote a famous book detailing all of this in 1999 called “The Code Book”. With an impressive challenge of 10 ciphers to beat at the end that had a monetary prize. It was fascinating.

    • @jasonbates9906
      @jasonbates9906 2 ปีที่แล้ว +3

      Read The Code Book as a kid. Loved it.

    • @jordancarpenter676
      @jordancarpenter676 ปีที่แล้ว

      @God Slayer I don’t know what this means. Sanskrit name so what?

    • @jordancarpenter676
      @jordancarpenter676 ปีที่แล้ว

      @God Slayer that’s not even punny. You’ve spoke a lot without saying anything.

  • @channelofoxford2131
    @channelofoxford2131 5 ปีที่แล้ว +113

    This is one of the coolest math TH-cam videos that I'v seen.

  • @Engel-ol5rm
    @Engel-ol5rm 4 ปีที่แล้ว +14

    Your channel was one of the factors in me wanting to study mathematics

  • @sahilkthakur
    @sahilkthakur 5 ปีที่แล้ว +73

    Because of you I'm learning mathematics with curiosity and meaning.👍👍👍

  • @91722854
    @91722854 5 ปีที่แล้ว +27

    I would like to recommend "The code book" written by Simon Singh

    • @glokta1
      @glokta1 4 ปีที่แล้ว +2

      +1. Amazing book

  • @pravatyadav3623
    @pravatyadav3623 5 ปีที่แล้ว +27

    Ur content are always original and exciting....makes me want to rewatch it time and again

    • @zachstar
      @zachstar  5 ปีที่แล้ว +4

      Thank you!

  • @haseebtubing
    @haseebtubing 5 ปีที่แล้ว +66

    Dude, you smart. More power to you.

    • @theulmitter5725
      @theulmitter5725 4 ปีที่แล้ว

      That's what I think in most of these videos, I keep watching even if I don't understand anything

    • @mk_4567
      @mk_4567 3 ปีที่แล้ว

      @Benjamin 😭😭 please don't say that, I can't understand. Can you help me?

    • @mk_4567
      @mk_4567 3 ปีที่แล้ว

      @Benjamin after the mod part it is complicated for me

  • @ilyaaslunat8382
    @ilyaaslunat8382 5 ปีที่แล้ว +65

    This is a really good video. I’m doing coding and cryptography as a module in my final year maths, and your covering the main points 😁😁😁

    • @enjoyablehistory5958
      @enjoyablehistory5958 2 ปีที่แล้ว +1

      Is enjoyable to study cryptography

    • @oyaoya2468
      @oyaoya2468 2 ปีที่แล้ว +1

      I'm currently studying abstract algrebra (group theory,ring theory,...) anh yeah, it along with number theory are really useful stuff for cryptography

  • @MrTokyo-wc6xr
    @MrTokyo-wc6xr 5 ปีที่แล้ว +35

    I was half way through then I released I hadn't yet subscribed, my bad dude. Love your channel

  • @majaano
    @majaano 5 ปีที่แล้ว +6

    Perfect in terms of detail, depth and presentation, thank you. On a level that I can just about grasp most of it, but not all of it without stopping and perhaps writting stuff down. I wish more topics were covered on TH-cam on such a level.

  • @computeon727
    @computeon727 5 ปีที่แล้ว +142

    You ever think about changing the name of your channel? You are doing lots of new amazing videos that are more geared towards the applications of mathematics to STEM fields, as opposed to talking about college majors as you did more frequently in the past. I like this transition of content in your channel as it attracts a wider audience instead of just college students. You could grow huge if your channel focused on these types of videos. Your college major videos were great and informative in the past, don't get me wrong, but now you've established a theme of mathematical applications that make your channel really unique and interesting!

    • @zachstar
      @zachstar  5 ปีที่แล้ว +40

      I have been thinking about this! I haven't really thought about changing the name because there are still majors I want to talk about but I have really enjoyed showing these applications of math to STEM fields and they seem to be received pretty well. I think I'm still just playing around with what people enjoy and what I like making so we will see what happens moving forward. Definitely a positive that these apply to a wider audience though which is something I have to think about. Thanks for the comment though and hope you continue to watch!

    • @jackmaison4209
      @jackmaison4209 4 ปีที่แล้ว +8

      Look how times have changed.

    • @iampaapa
      @iampaapa 4 ปีที่แล้ว +4

      Now, I really want to know what his old name was 😂😂😂

    • @bigbrothersinnerparty297
      @bigbrothersinnerparty297 4 ปีที่แล้ว

      Paapa Kwesi Quansah it is in his channel description

    • @bigbrothersinnerparty297
      @bigbrothersinnerparty297 4 ปีที่แล้ว

      Paapa Kwesi Quansah it’s MajorPrep

  • @simonmultiverse6349
    @simonmultiverse6349 3 ปีที่แล้ว +1

    The problem of passing notes in class is NOT ONLY that of secrecy. If someone knows that you have passed a note, even if they don't know what's in the note, you are STILL in trouble. Therefore, you have to (1) conceal the _contents_ of the note; (2) conceal the very _existence_ of the note.

  • @turtlemun
    @turtlemun 2 ปีที่แล้ว +1

    The beginning, one after the caesar cipher, is actually called the Vigenerre cipher! It's much easier to decode with an alphabet grid- you use one side as the ciphertext letters, and the other for the Key phrase. Match each letter in the ciphertext to its key counterpart and bam. Same deal for encryption.

  • @loserkingclinton9244
    @loserkingclinton9244 3 ปีที่แล้ว

    100 youtube tutorials later I finally understood modulo arithmetic!Dude you a genius.

  • @NovaAnimations
    @NovaAnimations 4 ปีที่แล้ว +18

    Honestly I really don't like doing math but this was so much fun to learn

  • @arunmalik790
    @arunmalik790 ปีที่แล้ว

    BEST VIDEO THAT EXPLAINED THIS MATH PROPERLY

  • @behnamasid
    @behnamasid 3 ปีที่แล้ว +1

    You explaining things could not get any simpler. I'm really happy to be a subscriber to your channel

  • @Bill_W_Cipher
    @Bill_W_Cipher 8 หลายเดือนก่อน +1

    1:29
    What if the other person thinks you are trying to say, "You can't rust me" instead of "You can trust me"?

  • @0ijm3409fiwrekj
    @0ijm3409fiwrekj 2 ปีที่แล้ว +1

    Cryptography was my second favourite module in my Maths degree.... only behind Number Theory ;)

  • @Nocbsocbsox
    @Nocbsocbsox 4 ปีที่แล้ว +5

    Today I learned that literally every number you can possibly think of had at least one thing in common.
    Relatively prime.

  • @chinmayrath8494
    @chinmayrath8494 ปีที่แล้ว

    thank you, i finally understand what congruence is about now ! The video until the end, absolutely great !!

  • @vlhz69420
    @vlhz69420 5 ปีที่แล้ว +1

    Imitation Game is the best movie on this topic till now

  • @perx5171
    @perx5171 3 ปีที่แล้ว

    Best video I have come across so far. Thank you for sharing!

  • @sharathkumar8422
    @sharathkumar8422 5 ปีที่แล้ว +2

    I'm about to go to sleep and this is the perfect way to start a good night's sleep. Very good presentation. Keep it up.

  • @AjayKumar-fd9mv
    @AjayKumar-fd9mv 4 ปีที่แล้ว +2

    It's super easy to understand when you explain to us, Thanks , but how someone had to think about it and invent it for first time?

  • @ericj4094
    @ericj4094 5 ปีที่แล้ว

    More common (civilians) AES-128 symmetric key encryption with RSA-2048 as key exchange mechanism (military) AES-192 or AES-256 symmetric key encryption with RSA-4096 as key exchange mechanism

  • @worldedit8784
    @worldedit8784 5 ปีที่แล้ว +1

    Thanks for this video. I wanted to learn more about this before desided to do it in university.

  • @elsie1379
    @elsie1379 3 ปีที่แล้ว

    This will help me with my cryptology paper for my number theory class! Thanks!

  • @purnendushukla8463
    @purnendushukla8463 2 ปีที่แล้ว +2

    It seems like you are highly interested in cryptography as i can see an elelment of it in every of you video.
    Btw well laid and explained 😌

  • @johnadriandodge
    @johnadriandodge ปีที่แล้ว

    Shalom
    Your clones caught me off guard.
    Your explanations are splendid.
    Thank you for sharing.

  • @johnadriandodge
    @johnadriandodge ปีที่แล้ว

    If you have not seen these movies, you might want to look into them!
    A Beautiful Mind, Good Will Hunting, The Imitation Game, Stand and Deliver and The Theory of Everything

  • @purityvsprofanity2962
    @purityvsprofanity2962 2 ปีที่แล้ว +1

    Still doing my IGCSEs and this isn't part of the syllabus, but why not learn it anyway??!! thanks for the video

  • @vinnaroonie
    @vinnaroonie 5 ปีที่แล้ว +4

    Great vid! Can you make a video on combinatorics? Taking it rn in undergrad and it’s chipping way at my life🙃😂

  • @JarppaGuru
    @JarppaGuru ปีที่แล้ว

    2:12 no need calculate just make 2 rings bigger and smaller with A-Z then turn smaller ring what key is to A first would be C under A now you look whats under Y yes there is B. no need calculate.
    same thing with long strip paper A-Z and A-ZA-Z "smaller is 2x longer" so its easy.
    was that so hard move key letter under A then look whats under letter you try encode that cipher letter. same it works backward move current key under A then look cipher letter then look whats is it decoded

  • @mancillagarfiasabraham8392
    @mancillagarfiasabraham8392 ปีที่แล้ว +2

    Hackers: WRITE THAT DOWN!! WRITE THAT DOWN!!

    • @gnt10
      @gnt10 25 วันที่ผ่านมา

      They know that stuff alredy😅
      That is if they actually are hackers😑

  • @dannys2817
    @dannys2817 5 ปีที่แล้ว +2

    Clear explanation, thank you

  • @HandsomEnchilada
    @HandsomEnchilada 4 ปีที่แล้ว +1

    never knew this existed .But im glad i found it .

  • @richkillertsm6664
    @richkillertsm6664 5 ปีที่แล้ว

    Two big mistakes:
    1. Vigenère and not vigener
    2. You don't need many messages to decipher Vigenère when the key is short, you can decode fairly short messages with other analysis methods. The only problem comes when the key is in the same length as the message (or close to it) and the key is random, which basically turns the cipher into One-Time-Pad.

    • @zachstar
      @zachstar  5 ปีที่แล้ว

      Thanks for the corrections. And I’m assuming you mean the cipher becomes more secure when it essentially turns into the one time pad? (Assuming one time use).

    • @richkillertsm6664
      @richkillertsm6664 5 ปีที่แล้ว

      Yeah, it's perfectly secure when we're using a random key in the same length as the message ONCE (hence the name One-Time-Pad). When used that way it is mathematically impossible to know the plaintext without the key.

    • @zachstar
      @zachstar  5 ปีที่แล้ว

      Okay yeah that makes sense. I was actually going to include a one time pad example using xor operations but didn’t have time.

    • @richkillertsm6664
      @richkillertsm6664 5 ปีที่แล้ว

      You can define OTP (One-Time-Pad) under with any modulo as long as the key is random. XOR is addition under modulo 2. When working with letters in Vigenère we work under modulo 26, and can be turned into OTP as described. Besides that there's no difference, and they both result in perfect security.

  • @zajec11
    @zajec11 4 ปีที่แล้ว

    Understanding 7:25 is the most important part, and without understanding that, you won't fully understand the rest

  • @brandonfox9618
    @brandonfox9618 3 ปีที่แล้ว

    10 congruent to 6 mod 4 isn't really the best way to put it because it contradicts part of the "Division Algorithm". Specifically, the part where it states that integer remainder "r" is greater than or equal 0 and less than integer "n" (0 < or = 6 not < 4).
    THIS IS JUST WHAT I HAD LEARNED FROM CONGRUENCE MODULO "n"!

  • @jaspaw.5473
    @jaspaw.5473 5 ปีที่แล้ว +2

    Hey, could you please do a video on Computational mathematics? Am taking it I would really appreciate if I could get your point of view about the program. Thank you in advance!

  • @kittymeow3298
    @kittymeow3298 4 ปีที่แล้ว

    An eighth grader learning cryptography.... Juuuuuust great

  • @alperenorsdemir4164
    @alperenorsdemir4164 ปีที่แล้ว

    I didn't know this guy is actually teaching technical stuff.

  • @SubduedRadical
    @SubduedRadical 4 ปีที่แล้ว

    a =- b (mod c) means "a has a remainder of b when divided by c", then?
    Seems that'd be an easier way to say it...

  • @vadimneonov6172
    @vadimneonov6172 ปีที่แล้ว

    I don't think at 9:47 'x' is any integer, because it doesn't work for 'x' that is divisible by 5. Please correct if i am mistaken.

  • @catherine_404
    @catherine_404 ปีที่แล้ว

    If we decided to pass notes in the class so that no one could decipher them if caught, the best method is us speaking some exotic language. Chinese or Japanese would be sufficient. There are many small living languages which do not have translator in Google.

  • @MatiGebreyehans
    @MatiGebreyehans 7 หลายเดือนก่อน

    What if we use algebric equation like y=4x+4 0r y=4y+4 is it too easy for computers to crack

  • @samuelfey4924
    @samuelfey4924 5 ปีที่แล้ว +1

    I love computer security I wish I was a super hacker but I ended working as a game developer I hope some day I get into computer security

  • @cubicardi8011
    @cubicardi8011 5 ปีที่แล้ว +2

    8:42 fermat reference right here

  • @sidneylc281
    @sidneylc281 5 ปีที่แล้ว +3

    Are there some books you can recommend about the math in cryptography? I know the basic stuff like theory and application by using libraries but I want to understand it deeply. Do you have a series or books ordered by difficulty? I know a book can't explain all about cryptography but you that explains must know a path I can take to master the math in cryptography. And also, awesome video, nir easy nir hard.

    • @zachstar
      @zachstar  5 ปีที่แล้ว +2

      'The code book' is a really good one to get started with cryptography. Then I personally haven't gone through a specific cryptography textbook before but this reddit post should help. From a mathematics side number theory is definitely a good place to start though.
      www.reddit.com/r/crypto/comments/287y7j/best_intro_book_to_cryptography/

  • @raulmogos1282
    @raulmogos1282 5 ปีที่แล้ว +1

    I really enjoy your videos! Please make a video on computational science and engineering (master specialisation). :)

  • @tuesdaymartesvr1942
    @tuesdaymartesvr1942 2 ปีที่แล้ว

    You needed to get nord von to sponsor this omg

  • @starshinesun738
    @starshinesun738 ปีที่แล้ว

    If use x=6 and p=3, that formula doesn't hold. Right?

  • @moustafaabousalem1411
    @moustafaabousalem1411 9 หลายเดือนก่อน

    Definitely earned a sub. You really helped me.

  • @leosacademy
    @leosacademy 3 ปีที่แล้ว

    Wow!!! very good video. I have learned many things. Thank you Zach Star

  • @johnohm8067
    @johnohm8067 4 ปีที่แล้ว

    you have to intialize a handshake and an ever changing multi algorithm encryption

  • @AkashDeep-bu9fu
    @AkashDeep-bu9fu 4 ปีที่แล้ว +1

    Can we say relatively prime numbers as coprime numbers?

  • @kd8691
    @kd8691 3 ปีที่แล้ว

    In the example at 7 minutes 10=6 (mod 4) >> 5=3(mod 4) why would you not perform the same operation on the mod? If you did would it not be correct? 5=3(mod 2)

  • @aiden359
    @aiden359 5 ปีที่แล้ว

    Information from your channel is so valuable

  • @giladlad
    @giladlad 5 ปีที่แล้ว +4

    Great video, but I think you made a small mistake.
    at 9:40 you are reffering to Fermat's little theorem , but in order to use the equation you used you need an integer x which is not divisable by p, and not just any integer you would like.
    for example if you use: x=4 & p=2 4^(2-1) != 1 mod(2) .

    • @zachstar
      @zachstar  5 ปีที่แล้ว +1

      Thanks! And yes definitely right, forgot to mention that part.

    • @99bits46
      @99bits46 5 ปีที่แล้ว

      giladlad Khoor nerd

  • @jonelong4020
    @jonelong4020 5 ปีที่แล้ว +28

    I have one idk what it is called
    IETRNCUOTOMOHSEM
    So, count all the letters which is 16.
    Square root of 16 is 4.
    Write the letters in a square form
    I E T R
    N C U O
    T O MO
    H S E M
    Read it downwards
    'In the costume room'

    • @xavierlondres6519
      @xavierlondres6519 5 ปีที่แล้ว +4

      hi mate its called ceazar's box. Correct me if im wrong mate.

    • @HandsomEnchilada
      @HandsomEnchilada 4 ปีที่แล้ว

      so written in asian scrolls style?

    • @SunSunSunn
      @SunSunSunn 4 ปีที่แล้ว +1

      @@HandsomEnchilada Why did you refer to scrolls from Asia? All scrolls work that way??

    • @HandsomEnchilada
      @HandsomEnchilada 4 ปีที่แล้ว

      @@SunSunSunn sorry don't even understand what i typed .I guess I was watching TH-cam during my TH-cam rabbit hole journey and forgot . I possibly was referring to "Asian scrolls "because from what I've seen in movies, scrolls often appear to be written verticaly

    • @RifqiPriyo
      @RifqiPriyo 4 ปีที่แล้ว

      It looks like columnar transposition cipher.

  • @W1LDGAMING.
    @W1LDGAMING. 5 ปีที่แล้ว

    Can we have some more videos on cryptography

  • @alleygh0st
    @alleygh0st 3 ปีที่แล้ว

    can't I just find a common factor and see if the results can be divided by the modular?

  • @sidstam
    @sidstam 5 ปีที่แล้ว

    Very impressive presentation and explanations.

  • @lucioleepileptique9195
    @lucioleepileptique9195 5 ปีที่แล้ว +3

    What is the message length of the universe ?

    • @clayz1
      @clayz1 5 ปีที่แล้ว +2

      Frank HEUSER 42

  • @aanya7607
    @aanya7607 3 ปีที่แล้ว

    I LIKE YOUR VIDEOS THEY ARE AMAZING
    LOVE FROM INDIA

  • @awkweird_panda
    @awkweird_panda 5 ปีที่แล้ว +6

    At 10:46 You should have said "how many positive integers....". You got me guessing infinity😂😂

    • @zachstar
      @zachstar  5 ปีที่แล้ว

      haha my bad! I did so many takes where I said 'numbers' instead of 'integers' and I was so focused on not messing that up.

    • @awkweird_panda
      @awkweird_panda 5 ปีที่แล้ว

      @@zachstar Haha. I really appreciate the Hardwork you put in.

  • @nitamishra9645
    @nitamishra9645 3 ปีที่แล้ว

    But at 7:11 shouldnt you also divide the mod4 by 2 which would equal to 5 = 3(mod 2) which would be correct

  • @sab2597
    @sab2597 5 ปีที่แล้ว

    Ø(7)=6x1 then how come its relative prime numbers include 1

  • @neelamsuryawanshi1137
    @neelamsuryawanshi1137 5 ปีที่แล้ว

    How do you explain someone that cryptography is use of mathematics majorprep?

  • @SBVCP
    @SBVCP 5 ปีที่แล้ว +2

    I laughed because the first time i tried to make a cesa cipher i ended up doing a variation of vigenere lol (it has a few complicatiosn but not that many)

  • @anuragpandey8996
    @anuragpandey8996 4 ปีที่แล้ว

    what if 10 ≡ 6 mod 4 devided by 2 equals 5 ≡ 3 mod 2?? check video at 6:18

  • @souling8773
    @souling8773 5 ปีที่แล้ว +1

    I don't understand euler's theorem at 11:45 . Can someone please explain or give me the name of the theorem?

    • @Gekreuzigt
      @Gekreuzigt 3 วันที่ผ่านมา

      That's Euler's totient theorem

  • @brendawilliams8062
    @brendawilliams8062 3 ปีที่แล้ว

    Nice I guess it is a math that some people really like.

  • @RickyPisano
    @RickyPisano 3 ปีที่แล้ว

    What about a cipher and key with letters, numbers and symbols as follows:
    TR#DUTR#DU6J23DAXX3 using key = 1#L-H1#L-HBEQ9-WNN9
    This is only a portion of it. Thanks.

  • @YoshikaKehelpannala
    @YoshikaKehelpannala 3 ปีที่แล้ว

    10:51, the primes under 10 should be 2,3,5,7. Nine is not a prime and 1 cannot be counted in.

  • @SAM-ft9jd
    @SAM-ft9jd 5 ปีที่แล้ว +12

    Your videos are truly stunning. The production is top tier considering the content you're putting out there. If anything you truly deserve more subs. Hopefully I can gain you a few by sharing your content on reddit? Eitherway just want to say keep this up, hope you don't ever doubt yourself or your content.

    • @zachstar
      @zachstar  5 ปีที่แล้ว +2

      Thanks so much! And yes please share the videos wherever you can, really appreciate it.

    • @SAM-ft9jd
      @SAM-ft9jd 5 ปีที่แล้ว

      @@zachstar Btw think it's possible you could do a few videos on information technology and mechatronics?

    • @zachstar
      @zachstar  5 ปีที่แล้ว +1

      Mechatronics is definitely one I still need to get which I've been really slow to do. But I promise I will!

  • @hannahtang5018
    @hannahtang5018 5 ปีที่แล้ว

    LOVE your videos!!! Numberphile is too hard for a nub like me

  • @danielpetrov3023
    @danielpetrov3023 5 ปีที่แล้ว

    I have a question. I tried it and saw that this works, but why when we subtract 1 from 3^8 the number isn't divisible by 15?

    • @zachstar
      @zachstar  5 ปีที่แล้ว

      Good question and I only mentioned this briefly but at 11:54 I say that x and n have to be relatively prime which 3 and 15 are not. Try it with 4, 7, 11, 13, 14, etc instead of 3 and it'll work.

  • @JarppaGuru
    @JarppaGuru ปีที่แล้ว

    4:25 yes yes yes but your encoded E is splitted many other letters and also other letter change same ammount to others you cant see whats E. its only work if your cipher is subtition
    means
    ABCDEFGHIJLKMNOPQRSTUVWXYZ
    MRHOPKVNEWBGTAZSQDLUCIJFYX
    then we could analyze that P could be E if it apper most but its not allways
    but if you shift that lower part every letter VOLA that P not occur anymore most lol

  • @diegovergaracampos2325
    @diegovergaracampos2325 3 ปีที่แล้ว

    Hi Im doing an essay of the topic, does anyone knows any bibliography of it ?

  • @taleofkaran
    @taleofkaran 4 ปีที่แล้ว +1

    DOUBT PLEASE CLARIFY
    But 28 is congruent to 4 modulo 6 holds true when divided by 4. This should have been false since greatest common divisor of 4 and 6 is 2 not 1.. Please clarify!

  • @78anurag
    @78anurag 3 ปีที่แล้ว

    Shoutout to those Chads writing programs and doing lots of math just so that I can text 'Haha big chungus so funny'

  • @uchicha666
    @uchicha666 5 ปีที่แล้ว

    11:23 the formula makes no sense at all... fi(p) = p-1, so fi(15) should be 14 right? And just above it there is equation where fi(15) = 8...

    • @zachstar
      @zachstar  5 ปีที่แล้ว

      15 isn’t prime

  • @abdullahalmalki2464
    @abdullahalmalki2464 5 ปีที่แล้ว

    hey, at 7:55, aren't 72 and 15 both divisible by 3 so they aren't relatively prime and this still works, or did i get it wrong?

    • @Plundarr
      @Plundarr 5 ปีที่แล้ว

      The divisor and the modulus, or the 2 and the 15, must be relatively prime.

  • @duailyp5142
    @duailyp5142 5 ปีที่แล้ว

    That eulers thing is cool and confusing

  • @pawanghimirey2195
    @pawanghimirey2195 4 ปีที่แล้ว

    is x^(p-1)=1(mod p), true for any number?
    or are there any exception?

  • @guillermoflores5511
    @guillermoflores5511 3 ปีที่แล้ว

    Farm fresh to you.

  • @henribebo
    @henribebo 3 ปีที่แล้ว

    Dude i love u

  • @celleian
    @celleian ปีที่แล้ว

    I love math but I'm lazy that's why I am never able to study and learn more. and can't reach more than 60%

  • @hklausen
    @hklausen 5 ปีที่แล้ว

    I like your channel :-)

  • @bardhokajvazi2726
    @bardhokajvazi2726 5 ปีที่แล้ว

    Is not 10=2 mod(4) ? Or i am missing something ?

  • @bolivianoman1831
    @bolivianoman1831 3 ปีที่แล้ว

    Me who just finished my first chapter of cryptography and I see this video: YAMETE KUDASAI

  • @heyho8361
    @heyho8361 3 ปีที่แล้ว

    But why tho?

  • @ravirajsinhzala9535
    @ravirajsinhzala9535 5 ปีที่แล้ว

    That was amazing🤗🤗

  • @johnnybokie1325
    @johnnybokie1325 5 ปีที่แล้ว +1

    3rd ??

  • @elibenaron
    @elibenaron 3 ปีที่แล้ว

    Message: You can trust me
    Me reading it: You cant rust me

  • @mohammedaasri2774
    @mohammedaasri2774 4 ปีที่แล้ว

    Thanks