Encryption and public keys | Internet 101 | Computer Science | Khan Academy

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  • Опубликовано: 21 авг 2024
  • Mia Epner, who works on security for a US national intelligence agency, explains how cryptography allows for the secure transfer of data online. This video explains 256-bit encryption, public and private keys, SSL & TLS and HTTPS.
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    Computer Science on Khan Academy: Learn select topics from computer science - algorithms (how we solve common problems in computer science and measure the efficiency of our solutions), cryptography (how we protect secret information), and information theory (how we encode and compress information).
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Комментарии • 144

  • @Dunit1117
    @Dunit1117 10 месяцев назад +17

    She's a great teacher. It's refreshing to hear someone explain technical things nice and slow. Slowing down gives people time to process the info.

  • @TickleTwinkleTwink
    @TickleTwinkleTwink 3 года назад +110

    YOU EXPLAINED THIS SOOO WELL!!!

  • @paul-cl3el
    @paul-cl3el Год назад +8

    her explanation is by far the best I saw on youtube
    simple and easy to understand

  • @moonshine4757
    @moonshine4757 2 года назад +25

    She's so good at explaining in the most simpler way. Great job 👏

  • @gabby993
    @gabby993 Год назад +6

    This is probably the first time I watched a Khan Academy at home on my free will. Other times was at school. Just because I was curious how encryption works

  • @sphinxz_gaming
    @sphinxz_gaming 3 года назад +6

    I have an exam for CS External Encryption So I started Studying this! Fully Explained! Thank you for informing us!

  • @fabricionunes8683
    @fabricionunes8683 4 года назад +19

    I’m going to learn English with this video, I like to learn two things at the same time ❤️ thanks

  • @rcubed1979
    @rcubed1979 Год назад +8

    Great video, very easy to understand! I loved the mailbox demonstration!

  • @shermayapaul8224
    @shermayapaul8224 Год назад

    I am here revising for my IT exam and I just felt a curiousity of how encryption works. She explained this so well and made it easy for me to understand. Thank you. You are very good at your job.

  • @hamzawaheed47
    @hamzawaheed47 4 года назад +5

    I just want to THANK YOU for clarifying my thoughts!!!

  • @scooby7877
    @scooby7877 2 года назад +7

    Something to keep in mind here is that SMTP (a protocol on port 25 for mail) can be used with SSL (a protocol for how encryption is made) so that you can securely get mail even if both protocols are on different ports

  • @parker797
    @parker797 Год назад

    The mailbox analogy was the best way I've seen of explaining public key encryption; it makes so much sense this way

  • @prekshajain6935
    @prekshajain6935 3 года назад +2

    No one has explained it so well ..Thanks for sharing it

  • @MrSreenir
    @MrSreenir 2 года назад +1

    Well explained. The Public Key can be shared after authentication before exchanging messages between computers

  • @artishzone
    @artishzone 2 месяца назад

    Thanks a lot for the great lesson! Your teaching style makes learning so much fun.

  • @ber2996
    @ber2996 День назад

    Im always wondering how the public and private keys works in the basic sense, now that example makes sense

  • @ryananderson8817
    @ryananderson8817 8 лет назад +14

    "This is what I'm doing with my work and I'm always about to lose my shit" :^)

    • @johnny14980
      @johnny14980 3 года назад +7

      How did u comment this 5 years ago? It says the video was posted 2 years ago

    • @dkbroman
      @dkbroman 2 года назад +1

      @@johnny14980 WHOA HE'S HACKING

  • @avitex2441
    @avitex2441 2 года назад +1

    Best explanation ever, its too easy to understand

  • @antoniorodriguez5138
    @antoniorodriguez5138 23 дня назад

    ¡¡Woooow!! Her explanation was amazing and only she is a young girl. Incredible!!.

  • @mic9047
    @mic9047 2 года назад +1

    Amazing video. I’m glad I found this channel to learn about networking!

  • @jean-francoisbec8358
    @jean-francoisbec8358 2 года назад +3

    Wow! It makes sense and it is really easy to understand with your words ! Thank you :)

  • @vinaybabupamu6190
    @vinaybabupamu6190 3 года назад

    One of the best video in internet to get started to understand encryption. Thanks.

  • @mukundumashankar3979
    @mukundumashankar3979 3 года назад +1

    dayummmmmmmm your explanation is sooooo nice thanks for clearing out my confusions in this short and amount of time .

  • @tharunthiruseelan4252
    @tharunthiruseelan4252 4 года назад +11

    This video was amazing.

  • @miteshd81
    @miteshd81 6 месяцев назад

    My daughter loved this❤

  • @nissimbracha1
    @nissimbracha1 3 месяца назад

    Thank you for this explanation! that was very halpful

  • @NeelSandellISAWESOME
    @NeelSandellISAWESOME 4 года назад +4

    This is really cool. It seems that with 256 bit encryption, it would take 2^256 guesses. The concept of public vs private keys is cool as well --> anyone can deposit in your mailbox but only you can access the contents.

    • @skyblue1599
      @skyblue1599 Год назад

      why 2?

    • @NeelSandellISAWESOME
      @NeelSandellISAWESOME Год назад

      @@skyblue1599 For every bit, we have two choices.

    • @nilsmustermann8454
      @nilsmustermann8454 Год назад

      I was a bit confused first, because 2^256 isn’t (2^256)-1 (number in the video; 3:17), but precisely spoken you don’t have to “try” the last combination, because you already know it’s the right one after trying all others

  • @leerdoor
    @leerdoor 2 года назад +1

    Extremely well explained. Good job girl!

  • @oopsy444
    @oopsy444 3 года назад +1

    we need to get a sequel course!!

  • @claverassanvo8495
    @claverassanvo8495 8 месяцев назад

    Amazing explanation... Pretty woman 👩 with Pretty ,true and simple knowledge about encryption and description of a message 😢Many poeple try to explain 🤔 😉 but they can't elaborate it well...
    Thanks🎉🎉🎉God bless you 🙏

  • @Krishcorner
    @Krishcorner 3 года назад +2

    Amazing explanation, so simple and clear

  • @abcdefghijklmn6940
    @abcdefghijklmn6940 Год назад

    Mia Gil is so cool and also explained very clearly!!

  • @meow710
    @meow710 2 года назад

    Daaang.... This is the explaination I'm looking for. So, logical

  • @tonykososki3016
    @tonykososki3016 2 года назад

    maaan this video is so great!

  • @bhavyasharma8661
    @bhavyasharma8661 3 года назад +1

    amazing explanation and amazing explainer !!!!! Thanks a lot

  • @farhhanr
    @farhhanr Год назад

    great explanation

  • @badrii07
    @badrii07 Год назад

    Good Job, thanks

  • @adyanathkaibartya7222
    @adyanathkaibartya7222 2 года назад

    Great Job, Mam
    Conference level infinity

  • @siskahernaning
    @siskahernaning Год назад

    thank you.. your video is so well explained

  • @labuewilfred2259
    @labuewilfred2259 3 года назад

    Thanks for the simple n clear explanation

  • @ananyaimtiazhussain6816
    @ananyaimtiazhussain6816 2 года назад

    Wow! Thank you. This helped a lot.

  • @bemotivated2203
    @bemotivated2203 3 года назад

    allways changing and challenging :) very well explained in simple manner thanks

  • @luis96xd
    @luis96xd 4 месяца назад

    Amazing video, everything was well explained and I liked the Mailbox example, thanks!
    I have a doubt, we use the Public Key to encrypt messages and the Private Key to decrypt them
    But, can we encrypt messages using the private key and decrypt them using the public key? Does this has sense? or it is not possible
    Another doubt, using a number key in Caesar Cipher we swap N times as the key says, but how does key work with they have letters?

  • @janeric1810
    @janeric1810 3 года назад +1

    I thought I'm too stupid to understand this, thank you very much

  • @sushilakarki3885
    @sushilakarki3885 Месяц назад

    No it will take about 2.78 hours for a computer to brute force a 10 digit code. Love your vids btw

  • @siyn007
    @siyn007 8 лет назад +123

    you can see the long hours of coding in her eyes

  • @nielsdaemen
    @nielsdaemen 3 года назад

    *Beautiful and smart!*

  • @fetajonathan2247
    @fetajonathan2247 2 года назад

    NIce explanation. KUDOS👏

  • @wazidalikhan2775
    @wazidalikhan2775 3 года назад

    Thanks, good information.

  • @mahdisfatima3218
    @mahdisfatima3218 3 года назад

    Thanks alot... I helped me alot

  • @hello_virals
    @hello_virals 3 года назад

    You are amazing thank you so much good luck!

  • @thidevaloka6081
    @thidevaloka6081 2 года назад

    Great work sis super supportive

  • @kiu8179
    @kiu8179 4 года назад +1

    Good viedo, very thanks i like the spanish subs

  • @prajwalmishra2722
    @prajwalmishra2722 3 года назад

    Best video..thanku

  • @thakibkorede
    @thakibkorede 3 года назад

    A very educating video. Keep it up

  • @marvismeng1953
    @marvismeng1953 3 года назад

    You are talented!!!!!

  • @dmoney141414
    @dmoney141414 3 года назад

    great video! thank you

  • @severianocuellar1327
    @severianocuellar1327 11 дней назад

    TOTP code (App Authenticators) is Symmetric
    and Hardware keys (Yubikey, Feitian, etc) is Asymmetric?

  • @fernandosanchez5117
    @fernandosanchez5117 3 года назад

    thanks, really nice video.

  • @rlyehdate
    @rlyehdate 3 года назад

    What a pro!

  • @brentdelosangeles2499
    @brentdelosangeles2499 2 года назад

    Amazing video!

  • @gustavoisidor2575
    @gustavoisidor2575 11 месяцев назад

    @khanacademy what about quantum computers for decrypting the messages without the private key and trying all possible combinations?

  • @AceofDlamonds
    @AceofDlamonds 2 года назад

    Thanks!

  • @shantanurai5911
    @shantanurai5911 3 года назад

    Thnx for video

  • @anntakamaki1960
    @anntakamaki1960 2 года назад +1

    Straighforward explanation.

  • @ricardoribeiro3281
    @ricardoribeiro3281 3 года назад

    awesome video.

  • @ashikvega
    @ashikvega 3 года назад

    Thanks

  • @sorintalpis8210
    @sorintalpis8210 5 лет назад +2

    Beautiful presentation and presenter

  • @johnhack67
    @johnhack67 3 года назад

    thanks

  • @anthonyarmstrong9196
    @anthonyarmstrong9196 3 года назад

    Wow. That's heavy

  • @nomanibnhafiz3876
    @nomanibnhafiz3876 2 года назад

    Too good

  • @AnhTuPhucDerrickHoangCanada
    @AnhTuPhucDerrickHoangCanada 2 года назад

    Encryption locls my info with institutions i trust!

  • @jeffbguarino
    @jeffbguarino Год назад

    There is other information you can use to figure out a message. Like "free pizza in the cafeteria" = "kmsg rpche ps upg ehimxlwji" There is other information here. The English language is the other information. There are only a couple of thousand common words. Two letters , is, in, on, to, etc. not that many. You could possible figure out a sentence of just by counting the number of letters per word. You probably know what the general content of the letter might be. For example a military letter of orders will not be a cooking recipe, so the word basket will be limited. If this letter is sent to you at a place where there is a cafeteria, then you have more information. Maybe they have free pizza once a year and you can guess what the message is just by putting together information from diverse places. If you see an encrypted 5 letter word , as the first word of an email. There is a good chance this word is "hello".
    Consider a baby who knows no language at all. They can figure out what you are saying. It takes a while but they know, and not from the actual words but all the cumulative information gathered up from the months of watching things.

  • @8877robert
    @8877robert 3 года назад

    Bravo.

  • @eddietime1811
    @eddietime1811 2 года назад

    Me: I only wanna hear about the math
    Her: we won’t get into that now
    Me:

  • @shamelessone1987
    @shamelessone1987 3 месяца назад

    I really need to find a video that doesnt use an analogy like the mailbox, like i need one where it explains to me how the encrption actually works and doesnt allow the public key to decrypt the the information.

  • @Gary-Seven-and-Isis-in-1968
    @Gary-Seven-and-Isis-in-1968 3 года назад +2

    You're an absolute genius, thank you for a fascinating video.
    Could you tell me if it is possible to find the encryption key for an Android photo file
    if the owner mistakenly wiped the encryption key from the phone?.
    Yes it happened to me and so far nobody has been able to shed some light on this
    commonly occurring problem with Android phones.
    By default from Android 6 upwards all data on the phone is encrypted.

  • @RealTacticalMax
    @RealTacticalMax 2 месяца назад +1

    I’m just thinking of what would happen to my potato laptop if I tried to decode one of these.

  • @chiraggoel3604
    @chiraggoel3604 3 года назад

    nice video

  • @SelmanErhanekici
    @SelmanErhanekici 6 лет назад +2

    Great presentation and explanation

    • @BlueProgamer212
      @BlueProgamer212 3 года назад

      3 years ago comment on a 2 years ago video

  • @beappreciativediligent1220
    @beappreciativediligent1220 Год назад

    I dont get it . If I have a public key of someone else. And g use the key to generate an encryped file with a file of my known content . Then why can't I reverse the encryption and derive the private key?

  • @MrKennym321
    @MrKennym321 Год назад

    There are two things I don't understand: If I encrypt an email message, for example using S/MIMES, how does the person I am sending it to get the key to decrypt the email? Secondly, how is a certified signature a guarantee that the email is safe? Isn't it possible for someone to hack someone else's certified account?

  • @thekeith1221
    @thekeith1221 3 года назад

    How does she work for the dod while still in college?

  • @hi_beemo1808
    @hi_beemo1808 3 года назад

    the quantum computer be like: what only 256 bit key? I'm I a joke to you?

  • @williammangani2151
    @williammangani2151 3 года назад

    Help me guys which school teaches Computer Science on an Online at affordable price

  • @urmomasf
    @urmomasf 4 года назад +2

    im still confused :( i just i dont know how to do it in my code assignment...

  • @DarkEagle01
    @DarkEagle01 3 года назад +2

    Can’t someone reverse engineer your private key from the public one? If you know how something is encrypted, doesn’t that mean you can decrypt it?

    • @Kitulous
      @Kitulous 3 года назад

      you basically have to bruteforce 2^128 or 2^256 keys in order to guess the private key :) no, there's no way to derive a private key from the public key

    • @johnny14980
      @johnny14980 3 года назад

      The whole point of encryption is to develop methods that are essentially irreversible.

  • @itboostaustralia8498
    @itboostaustralia8498 5 лет назад +1

    great video

  • @SoulXample
    @SoulXample 3 года назад +2

    “Some math that we won’t get into right now”. That’s what I came here to try to understand aargh!

  • @ArcadianArt
    @ArcadianArt 5 лет назад +2

    What they fail to tell you here while the blow encryption out of proportion is that the NSA, CIA and five eyes do not care about cracking codes when they have backdoor access to nodes. They can tailgate any message on the internet that triggers their attention. Encryption although affective to an extent is just being hopeful. It’s all about language mixed with encryption and avoiding the surface.

    • @ArcadianArt
      @ArcadianArt 4 года назад

      Isaac W go look up who looks after proton mails servers, and where exactly their servers are located. They even state in their website if you are a “Snowden” do not use proton mail. In other words it won’t protect you. PGP is overrated and filled with flaws. Look up my videos I made a video on PGP

    • @ebentee
      @ebentee 3 года назад

      @@ArcadianArt gonna check your videos and will definitely subscribe

  • @enahmoscar-phoenix7565
    @enahmoscar-phoenix7565 2 года назад +2

    Bruh I waited 5 minutes for the math…

  • @derpr00
    @derpr00 2 года назад

    To the part where processors get smaller and smaller. We cant go any further smaller anymore

  • @chadfreddy7820
    @chadfreddy7820 2 года назад

    Help me my teacher is constantly restarting the video so we can't get on the computers. Quick someone teach me everything I need to know about this.

  • @cycnr4062
    @cycnr4062 4 года назад

    Were is Theale green at

  • @teddyjones3055
    @teddyjones3055 2 года назад

    Idk, it seems like you could get the mail out of that box with only the public key.

  • @donnievitelloni3806
    @donnievitelloni3806 3 года назад

    A quantum computer will make this process obsolete one day

  • @SoylentSoy
    @SoylentSoy 3 года назад

    Wouldn't a forced decryption by a quantum computer GREATLY decrease the amount of time needed for a brute force attack? Just by the nature of how quantum computers have a third state outside of 0 & 1?
    I wish I could remember what made me think this while watching a video on quantum computers. Something about how a Q-Bit is actually guessing values? The video I watched had nothing to do with decryption, but I remember watching the explanation of how each bit, or q-bit worked made complete sense for application towards password cracking.
    Of course, there's always the possibility that I'm a moron and got it all wrong.

  • @lisam5802
    @lisam5802 Год назад

    federal agent

  • @michaelduvwiama1370
    @michaelduvwiama1370 3 года назад

    Who's here from Solent?

  • @madebymrnda
    @madebymrnda 7 лет назад +2

    saw dood