Secret Key Exchange (Diffie-Hellman) - Computerphile 

Poor Alice and Bob. Always exposed. Always out there. Never left alone. ❤️

The analogy with colors in this video is pure genius! Thank you guys, this was an amazing introduction to Diffie-Hellman!

5 years later and this is still done a million times a minute out there. Very well explained, thank you!

yessss him again

Random squirting of fluids... exactly what I wanted to see this early in the morning...

Nice! This is a subject I should have covered immediately after the Public Key Cryptography video, since that one lays out the problem of exchanging keys that Diffie-Hellman solves. Great to see such a clear explanation, I doubt I'd have gone to the effort to get coloured liquids!

Watched the defcon presentation from years ago given by the creator of the diffie-helman key exchange... It was absolutely fascinating. Dude is an innovator and pure genius. Seems like a nice guy as well

What I like most about this channel is the ability of the presenters to explain things simply without mathematics. That is real teaching, not reciting formal proofs and equations

1:04 First rule of cryptography: Unless your job is to create cryptographic algorithms, *never* implement your own cryptographic algorithms. You *will* screw it up.

I really like this guy. Been watching and rewatching his lessons for like 3 hours.

How curious, PBS Infinite Series have been talking about encription in the last few days. Now I've got double the encryption bonanza! This has been a good week.

Everytime I feel confused by e2ee or key exchange, I will come back and see these videos. Really helps.

I'm a simple man. I see a computerphile video with Mike Pound, I click like

This demonstration was a classic Parker square.

Excellent, clear explanation, and the colours really showed the process visually, thanks guys!

i love the style of the whole channel! proofs nobody really needs power point or laborious anmations.

Sir, you have sincerely helped me with my homework far more than my textbook ever could. Thank you so much for making these videos! :D

I am writing Javascript decryption libraries for Apple Pay, Google Pay and Shopify and came across this video trying to learn more about the theory. Fantastic!

Thank you. This video really made the concept of Diffie-Hellman key exchange clear for me.

Beautifully explained.

I've never seen a clearer explanation of DH. Thanks guy!

Great video and execution. Always I need to know how something in practice works to know if I really need it in my project and then I need to know the math behind to reproduce myself. I just got here again after watching the math video, beause I have to go back to solidify the knowledge.

One thing I liked about Hellman was that not only did he invent a clever way to distribute private keys he also invented a decent tasting mayonnaise with an enormous shelf life. It has been forecast that a jar or mayonnaise will still be more or less OK even after being stored at refrigerator temperatures for five thousand years. If the Ancient Egyptians had known about Hellman's mayonnaise recipe and had stored a few sealed jars in the pyramids we'd still be able to open them and make a decent tuna mayo sandwich. Probably long after the nuclear apocalypse we'll be eating Hellman's Mayonnaise probably with roach meat. Or maybe the roaches will win and eat Human Mayo sandwiches.

This helps soooo much with my university studies! Dr. Pound, your the best.

Very simplified approach of teaching. Great video

Finally explanation of the main part that's missing like literally everywhere else. Good lord.

This might be the quarantine talking, but I’m starting to get a crush on this dude

Such a good video! Really clever concept, and the colour analogy is great! Cheers! :D

Great video, but surely the simpler method with the colours would have been to have ramekins with clear water and then add X drops of food colouring for the stages?! 😂

Recently discovered this channel and I love it ❤

I was actually looking for a good Diffie Hellman video a couple of days ago - how convenient!

I just love this guy! Keep him comin'.

2:53 that sound though! =)

I would have understood a lot more mathematics had it been presented so intuitively!

Best explanation of DH with such a simple example ..great work ..keep it up

Great explanation. Makes this concept really easy and straight forward to understand. 👍Thank you

your presentation is so clear and understandable, thanks a lot

This is the best explanation of key exchange i came across, thanks for uploading this

Fantasticly simple and easy to understand explanation, thank you for this. I'm studying for the Sec+, so basics atm. But i've been getting very confused by some of the terms around encryption. I'm going to ask a completely naive question. I understand to encrypt there are two components, 1) the algorithm, 2) the key. I've seen Diffie-Hellman described as a) a public key encryption algorithm, b) a key exchange protocol, c) a public-key encryption protocol. RSA is also described as an asymmetric public key encryption algorithm. Diffie-Hellman only generates keys, it does not provide an algorithm for use with those keys to then encrypt data RSA also generates keys, but can also encrypt/decrypt data So, my questions/assertions: 1) Is there general misuse of the term "encryption algorithm" or just "encrpytion" as to what that encompasses? What should it encompass? 2) My current feeling is, Encryption = 1) the algorithm, 2) the key (but not the key generation). Encryption algorithm = 1) literally just the algorithm, not the key. EErr, i don't know what term to use that would also encompass the key generation bit. So yeah confused still. 2) The process of Diffie-Hellman key generation/exchange is still considered an encryption algorithm because it outputs data (the shared public) that makes deciphering the input to create it practically impossible? 3) Diffie-Hellman is considered asymmetric because it generates a private/public key pair first? 4) Diffie-Hellman can also be used to generate asymmetric keys ONLY? 5) So the private symmetric keys Diffie-Hellman creates would form the symmetric keys for one of the symmetric encryption algorithms like RC4/AES? 4) Looking back at the above then, the term encryption looks like it should actually include the discrete phase of key generation/distribution?

Amazing video. I could not have found a better teacher. Thank you so much.

amazing video, thanks Dr Mike Pound!

What a wonderful demonstration!

Thanx! I got NOW my college about EXACT this and your explanation is way more clear

Thanks for whole serie of videos! I found something useful for my students and it is great!

This is the greatest video I have watched on encryption, ever! Thanks a lot.

i always wanted to know how was the very first aproach! now i know! thank you! great video, keep up with your excelent work!

Hey, thanks! I was still having issues with this but your visual representation really helped :)

This is so simple yet so effective. Very interesting.

Dr. Mike Pound is just a great great teacher

What an incredible video! Fantastic way to understand how VPN key exchange works!! Thumbs up

Great explanation, I have been searching and no one has explained it as well Thank you

Nice, fun and accessible way to explain it :) Really enjoyed the analogical explanation Thanks for sharing 🙌

A very clear explanation as usual, but it would have been nice for Mike to briefly mention that a trio at GCHQ - Ellis, Cocks and Williamson - came up with the idea first.

I have been so clueless with cryptography and cannot find one braincell to focus on most reading material (darn you ADHD) but stumbled along here and it made complete sense, wow.

so glad that your video made it in the bibliographie of my PFE

Finally understood the Diffy-Hellman concept. Thanks

Mathematical squirtings, LOVE THIS GUY XD, i follow this guy almost for a couple years, such a MVP

Brilliant. My professor could not even come close to such a great explanation.

You just got a new subscriber. Excellent content mate.

Great visual analogy. Thank you!

Excellent explanation. Loved it

tomarrow I have new sec and cryptography exam, and this topic has high possibility of coming, this is the best explanation I found,

what a terrific explanation. Terrific, and thank you!

Mike Pound?? Instant like! :D

I would like to Thank you Dr.Mike Pound for this information. it make me understand what is Diffie-Hellman is and i would like to take this video to be your reference in my work i have been put credit for u i really appreciate what u have done for us this video is just 8min it fun and i love this video Thank you

A very clear explanation - many thanks!

This video makes so much sense. And I get that it would be used to exchange, say, an AES key. But I thought symmetric keys were exchanged with asymmetric encryption, such as RSA. When would one chose DH instead? (Answer probably in another video)

Spectacular explanation. Thanks !!!

Superb video!!! Great job 👍👏

FINALLY. Love your videos

Huge fan of u sir....started encryption watching ur videos.....love ur accent

my favorite video on youtube!

Awesome explanation!!!

Finally I have understand it with this simple example. Big thanks.

Very well explained and elaboration are very clear.

This is an excellent explanation, thanks a bunch!!

Just love this guy !!!!! Great explanation!!

This guy is a genius. The explanation method is high level. You must be a teacher. 😍😋

this is so well explained. Thank you!

Fantastic content!

Best breakdown ever

this guys saved my semester.

very nice video, plain and simple explanation ;D

This guy is absolutely awesome. Thanks a lot.

Awesome explanation. 👌👌

One of these mathematical functions is: Alice sends g to the power of a (modulo prime number p). Bob sends g to the power of b (modulo p). The shared key is then: g to the power of a (modulo p) to the power of b (modulo p) which is the same as g to the power of b (modulo p) to the power of a (modulo p).

Amazing explanation.

Stellar explanation.

Great explanation! Thanks!

I love Mike.

Dr. Mike is the best!

thanks for the wonderful explanation 👍

Great explanation!

Splendid video

Very well explained!

6:40 "Mathematical functions that are much more precise than my random squirting of liquids" bars

Neat, I finally understand the basics of something I was always curious about. But now I'm thirsty.

you are singlehandedly saving my degree

That's just straight up brilliant. How does someone even come up with this?

Another Mike Pound video :D