Public key cryptography - Diffie-Hellman Key Exchange (full version)
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- čas přidán 29. 07. 2012
- The history behind public key cryptography & the Diffie-Hellman key exchange algorithm.
We also have a video on RSA here: • Public Key Cryptograph...
The color analogy is amazing. Great work simplifying a difficult and important concept.
Yes! This is the first time I have understood this concept due to the color analogy.
Analogies are so powerful
I really enjoyed this. Thanks for breaking it down.
It's good in that it's simple, however unlike the discreet logarithm problem, you would be able to make a good estimate of the secret colour based on the starting colour and one of the mixed colours. For example if Eve received the starting colour yellow, and a mixed colour green, she can infer that the secret colour mixed in must be some shade of blue, which makes her search much easier. Recognizing this threw me off a bit at first.
The concept is simple and genius.
by far the best explanation of public key encryption EVER.
thanks for watching! stick around
unfortunately, public key is completely different than key exchange. public key requires different keys to encrypt and decrypt, so there's no need for diffie hellman to agree on a secret key.
made another vid: czcams.com/video/OFS90-FX6pg/video.html
This is precisely how mathematical concepts should always be explained. You guys nailed it!
would love your feedback again czcams.com/video/OFS90-FX6pg/video.html
A great illustration. Diffie-Hellman has a well-known, fun vulnerability. Spoilers: Eve, knowledgeable herself on color theory, intercepts messages between Alice and Bob not letting their messages go directly to them. Instead she creates a color of her own. Mixing it twice with each of Alice and Bob's colors she creates two keys. She can now read Bob's message, re-encrypt, and send to Alice and pose as Bob. Same goes in the other direction. If only Alice could trust Bob's color comes from him.
an underestimatted comment
This is why you typically use a digital signing algorithm like DSA to authenticate the messages from each party.
if only (epic RSA foreshadowing)
This is called the man-in-the-middle attack.
Key signing parties!
Martin Hellman said:
The system...has since become known as Diffie-Hellman key exchange.
While that system was first described in a paper by Diffie and me, it is
a public key distribution system, a concept developed by Merkle, and
hence should be called 'Diffie-Hellman-Merkle key exchange'
if names are to be associated with it. I hope this small pulpit might help in that
endeavor to recognize Merkle's equal contribution to the invention of
public key cryptography.
I nominate this video for OSCAR !!
Yeah Oscar would definitely like this video
Computerphille uses the same technique.
"While Eve is stuck grinding away at the Discrete Logarithm Problem"
Hahaha that's definitely the best part right there.
I am typing typing this message in 29/10/2020 and this is one of the best and easiest explanation about public and private key system ever. well done.
great to know people still find this
I've watched a few videos on public key cryptography, but never really understood how it worked until I heard this colour analogy. Absolutely phenomenal video!
this is the best explanation I've seen on anything.
Time hardened Encryption just like safe hardening how much time is needed to open it. I love this, this is the best way to explain encryption ever. I love how they have IBM sage running for this video also. Amazing
Colors made it wonderful to comprehend... really impressing!
Akash Verma now. I think that I understand how my Gizmo (for online banking) from HSBC works........
I actually needed the numbers to kinda grasp the concept...
My background in advanced math concepts is somewhat limited, and so it's always been difficult for me to intuitively grasp how DH worked. After years of struggling, this is the one video that really drove the point home for me. Thank you!
dafuq YEARS? i grasped it in about 15 minutes lol
Oh my god, your content would fit SO WELL into a podcast format! It's something we need!
Funny you say that, i'm working on developing a podcast right now. I was town between just using the audio from these or doing a new conversational approach. can you listen to the demo I posted last week and give feedback? czcams.com/video/1w4Y_sCDeCE/video.html
@@ArtOfTheProblem wow sorry, I don't know why I just got this notification now, but I did listen to the demo and I loved it! Keep it up :)
One the best and simplistic explanation of what appears to be a complex algorithmic process. Thank you.
LOL ... I came for Diffe Hellman lesson. Got a lesson in Cold war politik.
THIS IS THE EASIEST EXPLANATION OF MODULAR MATH I'VE EVER SEEN
Why didn't I have this channel 10 years ago when I was in college??!!
wow finaly the video i was looking for with the best explanation and number proving examples
thank you very much I also checked your chanel realy awesome
+Malmizaur Episode 3 is up next: czcams.com/video/4qN9OvvEPr8/video.html
you are a magician !
Now i understand clearly about diffe Hellman method. Lovely and lively demo video. Thanks for making this wonderful video.
thanks please share and stick around for more content.
@@ArtOfTheProblem yes.thanks for your valuable reply.
Brilliant trick behind Diffie Hellman explanation is very clear.
Thanks a Lot.
Most amazing and simple and clean explanation of Diffie-Hellman algorithm I've came across. Great!!!
Good explanation, better than those explanations given by the professors in lectures...
My tutors can explain this to me for 1 day and I still don't get it.
Now I find this concept extremely simple.
Very nice! Hat off! One of the best explanations I have seen, and nice put into the story. however, when you swap those powers, you should use parenthesis, that is because generally, powering is not commutative. That is, a^b^c is not equal to a^c^b, modular or non modular powering. Powering is right-associative. But (a^b)^c=a^b*a^b*...a^b (c times) which is a^(b*c)=a^(c*b)=a*a*a*a.... (b*c times), which is (a^c)^b always, modular or not. This is due to the commutativity of the _multiplication_ operation. Not the powers.
Still one of the absolute best videos for explaining asymmetric key pair encryption
she's an oldie !
"without letting Eve, who's always listening.."
brilliant video, amazing explanation
thank you!
The trick in a nutshell:
( G^*a* mod P )^*b* mod P = G^*a*^*b* mod P = ( G^*b* mod P)^*a* mod P = *key*
*a* and *b* - private numbers
*key* - private key (same for both)
G - public generator
P - public prime module
( G^*a* mod P ) = *A*
( G^*b* mod P) = *B*
*A* and *B* - public numbers
both sites do:
*A*^*b* mod P = *B*^*a* mod P = *key*
I try to calculate in Javascript but found it not the same, is there any wrong?
According to the fomula "( G^a mod P )^b mod P = G^a^b mod P",
Assume G = 3, a = 13, P = 17, b = 15
Math.pow(Math.pow(3, 13) % 17, 15) % 17 = 10
Math.pow(Math.pow(3, 13), 15) % 17 = 2
Math.pow(Math.pow(3, 15) % 17, 13) % 17 = 10
But 10 is not equal to 2
Not clear how A^b = B^a
Paste this into console: Math.pow(Math.pow(3,15)%17, 13)%17
Result should be 10
This is an excellent explanation of what is usually a difficult issue to understand. Thank you!
Thank you for taking the time to record and produce this video! Beautiful explanation.
For a few months, my teacher didn't manage to explain this to a class.
In 8 minutes, this video can explain it to every dummy.
If it's simple, keep it simple.
Single best explanation on any cryptography concept I've seen.
That's called magic math. Great video. Very helpful. Now to watch the series.
THIS DID IT!! You helped me understand a few points that, in my opinion, we’re not pearly presented in other videos. Thank you very much.
Best explanation you can find on the internet about this. The color analogy is Godlike
Videos like this are always remind me why I am fascinated about the cybersecurity field! This is a fantastic video!
Perhaps the best explanation of private key exchange on the internet. Thanks very much for this video!
This helped me understand it:
Imagine Bob and Allice want to teleport to some secret planet without Eve joining them.
1) *Neither Alice nor Bob have a planet in mind where they would like to meet*. They want to use their own piece of puzzle to mutually arrive at the same planet. Depending on which private keys they've chosen initially the final planet will be in the very different locations of universe.
2) They publicly pick which galaxy they want to be in
3) They can pick any number they want, scramble it with the publicly known galaxy's name, and send it over to each other.
4) now each one has the scrambled piece of another person. Both pieces were scrambled with the same galaxy.
5) scrambling Allice's piece with the scrambled code received from Bob will teleport her to planet XYZ.
6) Bob will do the same thing with the scrambled code received earlier from Alice, which will teleport him to planet XYZ
because Eve didn't mix-in any of her information into the exchanged (scrambled) messages and was only listening to their conversation, she is unable to align herself with the planet XYZ where those two went.
Even if Eve would substitute her message instead of Bob', this would only result Alice and Eve arriving to FZK, without Bob. Alice would see that it's not Bob and no information would be disclosed.
This was dramatically more helpful than the meager amount of info my book offered on the subject; thank you.
I found your video while studying for a technical certification. Very well done. Thank you :D
Use of mixing colors as an analogy to explain the DH concept was brilliant. I know DH concept well, but never thought of the color analogy. Good job!
Oml dude this is exactly what I have been looking for! A visual explanation on how it works ! 10/10
fantastic video, explained something I've wondered for a long time, Thank you.
Much better than the short version which confused the hell outta me @4:35!
Thank you very much for posting this!
I learned more from this video than 5 weeks worth of lecturing in my university class.
I don’t know what your background is just amazing explanation of concepts
I did a degree in CS and Engineering however I've always enjoyed explaining things. thanks for the feedback
Great video explanation. I loved the demonstration of colors & Mod Calculus Clock rope.
if this was 2 hours, i'd still watch it. awesome explanation
I love it! (this is the first thing I publicly love on the internet) :-)
wassollderscheiss33 That's so awesome. Thanks for the love
that colour analogy was mind blowing. made my day!
Amazing explanation! The best video about DH Algorithm. Thank you, it really helped me a lot.
Thank you sooo much for putting time and work into this video.
you've helped a lot of people around the world
Brilliant explanation about key exchange for those of you interested in how your data is encrypted over the web. Ok, when the maths comes you need to pay attention but all in all the best explanation I've found.
Cryptography 101, the best intro ever!
Excellent video! My only complaint is the explanation of "how Alice did the same calculation as Bob" from 7:27 to about 7:40. Starting at 7:27, we see that "12 = 3^13mod17". Then conveniently, right at 7:34, when that figure is substituted into Alice's original expression, the "mod 17" DISAPPEARS and the 12 is simply replaced by "3^13". Although this IS mathematically correct, it REQUIRES a rather advanced principle of modular arithmetic: namely, that [(a*mod c)^ b]*mod c = (a^b)mod c. (In the example from the video, a = 3^13, b is 15, and c is 17). So, you effectively CAN simply remove the extra "mod c" term, but the video glosses over this difficult but crucial step. My sister and I just spent 2 hours figuring out the proof for this principle. If anyone's interested I can share a photo of the completed proof. (It can be found online also).
Even I was stuck here
Yo yall are smart AF
Amazing and excellent explanation. Better than my lecturer!
I'm not even a math guy or even like numbers that much but every once in a while I come back to this video purely because of how entertaining it is
that means a lot
Your videos are great. They have interesting visuals as well as an easy voice to listen to.
Very well explained. I would recommend this video to anyone studying the arts of encryption/decryption.
This is such a good explanation, it makes so much sense logically to me now.
It was just awesome, u played wid the colors and dat made the algo go so simple to understand !!!
Thank you for making this video, great explanation and brief history of the concept! Keep on, keeping on!
Can't thank you enough. Awesome video. I wish you also explained how the digital signature works in order to avoid Eve pretending to be either Bob or Alice.
this kind of learning material is actually i m looking for. Great explanation
.
LOL I've been explaining this idea using colors for about 6 months, then I find your video! love it!
definitely an awesome video show you how to understand Diffie-hellman key exchange
Great video! It helped me an insane amount understanding the public key cryptography consept.
Fantastic. I've watched many videos on this same topic; nevertheless, this is The Best one. A million thanks for breaking down difficult concepts in an easy, understandable way. Kudos!
appreciate the feedback. I always watch every video on a topic before making a new one, so i'm glad you noticed :)
This is ingenious. Thanks for sharing your knowledge and creativity and helping people to understand so easily.
appreciate the feedback and comment, stay tuned!
The best explanation on CZcams .. thank you very very much ❤️❤️
why can't i like this video more than once? thank you for an excellent explanation
Deep concept but simply explained. Excellent!
AWESOME!!!! Please keep on teaching... You did a great job!!!
Best explanation I have ever seen. Well done!
The articulation is excellent! Great read
This video is so awesome! Had been looking for the answer to this problem.
very smart.. my teacher also explained it in a wonderful way so it stuck in our minds .. bless him
I really really like the music in this video. It mysterious. I like the fact that you take your time to explain and it is also visual. Nice creative video.
Took 2 years to finish this one, finally live would love your feedback: czcams.com/video/OFS90-FX6pg/video.html
EXCELLENT EXPLANATION. Thank You!
Amazing!!!! This is the best explanation that i've ever seen.
Lovely videos. .... awesome way of descriptions. .... awesome job.... very well done guys
This is really a great set of videos. Thanks and great work.
I'm reading wiki trying to understand how public-key encryption works (I'm told its better than symmetrical encryption). I remember someone tried to explain this before using colors, so a quick search--and I find your video. This is a great video.
Great video. I like the intro and examples used.
Linked to my cryptography teacher, this is how he should explain this to the class.
Excellent explanation of a hard thing to understand. Thank you! (Cool background music too!)
That's a wonderful example!!! Mind blowing 😍😍😍
Thank you so much. Really helped me understand the concept. And I thought I was just going to have to fail my certification exam.
Very nice i was thought about the color logic in my college but i wondered how it would work in numbers.Excellent video.
Amazing you fully explained this using paint!
This is the best explanation by far.
Algorithm explanation was really simple and effective
Outstanding explanation.
Just......beautifully and succinctly explained!
thanks for the feedback, stay tuned for more
well this was an incredible video. such a good explanation. well done!
Really good explainded. Helped me a lot, thank you for making this!
Great video, clear explanation. Thanks
Great job! Very good explanation.
Amazingly explained...I think it is bestest explanation ...thanks for sharing..
This is so beautiful theory. Really amazing!! Thank you for showing:)
Very well explained. Thanks a tone for your effort.
I just love this, everything is so much easier!