• ### Μιχάλης Καστρινάκης

6:40 it would be easier if you divide 4194304 by 14 which equals to 299593.14…
then we take the integer part (299593) and multiply by 14 which is equal to 4194302..
and now if we subtract 4194302 from 4194304 and we get 2 which is equal to number B

• ### Reuben! Edmunds

How would you put this into code so you could put it into a computer so it's a lot faster to decrypt and encrypt

• ### Anar Key

"Does that make sense… yes"… fascinating but I do struggle…

• ### Lancelot The Knight

Excuse me sir Woo, is the 14 the public key? Because 5 and 11 is a private key right?

?

• ### Benny B

Great video, thanks for the help! 🙂

• ### Worldaviation 4K

This makes more sense than some other videos that i searched for in other places with the fictional alice and bob. Proper detail like in this video with the actual numbers is far better than other videos i've seen elsewhere

• ### Dawn Ripper

Uhh, can't you just multiply 299593 by 14 and see the difference between that and the original number which is 2, btw?

• ### Nigel Bess

1:14 is now relevant on r/dankmemes

• ### bobbyj joel

Brilliant teacher.

• ### John Runyon

You'd be awful screwed if the plaintext was O…

• ### Lambert Brother

I used p=3, q=5, e=7, d=23, encrypted the message 'C' and the result was 'C'.

• ### Imisambi

how did you pick the numbers… 11…and 5 ..? was is related to extended euclidean algorithm..? thanks!

• ### brbl

Where did 11 come from?

• ### PoisonedHive

Eddie, you helped me pass my Codes & Codebreaking Unit at Uni. Thanks!

very good

• ### Navi Crazzy

someone, please give him something to eat…

nice bro..

• ### Matt T

Man… This is the definition of a good teacher. You can explain things very well and in a succinct manner. Great video!

• ### Defender2516

Girls if your going to talk, PLEASE LEAVE the classroom and go talk outside. Sometimes good teaching lessons are just absolutely wasted on students who don't even know why they are there.

• ### Dixing Xu

Best teacher!

Bright guy

• ### John Goh

Hi Eddie is there anyway subset sum problem can be used to modify RSA?

• ### Buda Yen

You send me D

• ### danielsan

@eddie. thanks

• ### Bryan Shepard

The reason he got 1.99….88 instead of 2 is because of floating-point arithmetic. For a computer, the fraction 1/3 does not have an infinite number of 3's, because the computer doesn't have an infinite amount of memory. When a computer stores a number into memory, if must first allocate how much memory that number will occupy (usually a power-of-two-times-eight number of bits). Then it stores as many significant digits as it can, but most of the time this means some get chopped off at the end or rounded off. As we do math with these truncated numbers, the effect of rounding errors grows.

• ### ali ulo

I wonder if all slightly more complicated concepts could be be explained in such a lucid way, or this particular problem allows for it. Anyway, that's no all to it: my respect, Teacher:-)

• ### Ben Terry

You explained clearly in 8 minutes what I couldn't fathom in a 2 hour lecture, Thank you, you're a credit to good teaching.

• ### Dr Michael S

Don't need calculator to do 4^11 mod 14, the nice thing about mod is you can do stuff like 4^11=4*16^5, which reduces to 4*2^5 mod 14 and now the previous calculation gives 16 mod 14 which is 2.

• ### Codingmaster

LOL EZ FLOATS ! XD ! ( 7:38 )

• ### Tomasz Górka

Have to say this, you saved my life, that's the best explanation on the web and I have to do this as a homework for tomorrow, thanks!

• ### Max Echendu

Realizes he's not subscribed to Eddie Woo the master of knowledge…
Flips…
Punches a hole through a wall…
Calms down…
Smiles…
Watches video…

You can continue scrolling the comments now…

• ### Arzu Arzu

29 Oct. is my birthday !

• ### MetraMan09

disrespectful class. have to blame the teacher on that one though… gotta coral the herd!

• ### George Henderson

I figured it out in about a minute and a half.

• ### Tony Joseph

http://www.quickdevtools.com/conversions/hashes/

• ### N Ash

If I had Eddie as my teacher I'd have done SO much better in math.

• ### soundhar gs

Oh man! The way you handled yourself is awesome and the lecture was so clear and perfect one i have ever seen!

• ### Jijus Chreest

"Sir, is it always going to be 11?"
How dumb can americans be?

• ### Arul Murugan

Best explanation ever. Love you Eddie woo.

• ### Brent Edds

I want a teacher like this

• ### Panzone Caduto di Faccia

2 hours of lecture in my uni and I didn't understand shit, 8 min of video and I feel super confident about rsa.
Thanks man you a great professor

• ### Daniel Ustarez

An asian guy using calculator? dishonor

ur gay

• ### Nick HOLMES

I wonder what time the Yoga class turns up.

• ### Zhaoxun Yan

The "lock" analogy is much better than the "public key" terminology.
I came up with this idea soon after I learned the RSA and I am not alone.
I wonder why they have not changed the terminology yet?!

• ### محمد

this teacher is GOLD

• ### Md Anwar Jamal

really fantastic Sir

• ### Rakhi Dhavale

This teacher is a amazing with his teaching skills ??

• ### Thomas patrickson

Thank you so much, great video and your a great teacher.

• ### Graham Bond

I have RSA deciphered from boredom 🙂
mod(n, round(x))=0 gives immediately p and q

• ### Graham Bond

4=mod((round(x))^5,14) {x>0} first x on the left =2

Lakhmanigi

• ### ScubaTech Productions

Eddie, I just wanted to say THANK YOU! This video taught me more in 8 minutes than I was able to figure out in 2 hours trying to decipher (hah) my textbook. Stay awesome. 🙂

• ### An Ché

Boy, I love this man! ?

• ### Joel kashaija

can some one explain me how he got 4 from 32

• ### Dev Vanana

Text :123
Cipher text : 123^5(mod 14) = 9
Decryption : (11, 14)
9^11(mod 14) = 11 (I expected it would be 123)
Why 11 is appeared instead of 123?

• ### CO DING

it video is great. teacher is very good and handsome.

• ### ┓┏ 凵 =╱⊿┌┬┐

i get computer science…this helps

im kinda gutted you didnt explain how you got to that decryption key

• ### Android 4 All

Sir this way i think not guarantee to get the result when u decipher you can find , fi(n) then you can easly finding d thats the key we wont

• ### Graham Bond

The music of the Prime Numbers, part 4, Solution.
https://youtu.be/d6NBGgQY1KU

• ### Ivan Rodriguez

Excellent and very clear explanation! Like it!

• ### Sharif Khan

Dude finally I understood it. Thanks for using math. My mind works better with numbers.

• ### Rajivrocks Ltd.

Wish i had teachers like this guy, all my teachers at my Comp science course are ASS and we have to learn everything ourselves

• ### saloni gupta

Amazing video!

• ### xavier santos

where did he get from (11,14) ? The 11 I'm confused about

• ### [DAN THE GREAT]

can a vpn tunnel be encrypted by RSA?

If AES and BLOWFISH can encrypt a tunnel then RSA probably can…Can Someone confirm or deny?

• ### OutOfControl

Hi Eddie, I know this video is a few years old but thank you so much. I've struggled a lot with this from watching other videos and reading about it online. This video made it so easy to understand, thank you!

• ### Wang Isabelle

???? I dont understand… I took some computer science class and I though the reason its 1.9999 instead of 2 is because of something to do with floating points notation and such????
Also, talks about "not going to use s string as example" but will talk about the "math behinds it", proceeds to talk about string as example and leave the math part as a homework…

• ### Jude Scally

Great video, can't wait to start working with you!

• ### Miksu

But 4^5(mod 14) is again 2 so the lock can actually unlock itself? Then it is not so secure after all. Does it only work with greater numbers then?

• ### Ste ame

Very interesting video, you are really a good teacher.. you helped me understanding RSA procedure, thank you 🙂

• ### Aayush Sinha

I wish I had you as my Professor in Uni.

• ### sean malone

Not only did I just see the best explanation of RSA encryption that I've ever come across, I got a free yoga lesson as well.

• ### tharuka ravishan

Where does the Number 11 come from…

• ### Caio Lucas

I wish i had you as my maths teacher in high school and now at university :'(

good

• ### zermello franck

thank you so much thars help me to understand so clearly, thats the most simple calcul in the cryptography

• ### Lynda Openshaw

although one is totally behind the concept of people/ companies/ lobbyists/ and just people who believe they are doing the right thing the letters RSA really does stand for Republic of South Africa Algorithm and encryption aside
type i RSA you will be enamoured

• ### SURESH SHARMA

Check out this 3 minute RSA Algorithm video also. This is a good one. https://www.youtube.com/watch?v=mkDvyCV8Nzk

• ### Wellington P Ferreira

that goes my whole semester

Best teacher

• ### RagazzoKZ

It's a very bad explanation of RSA!!!

• ### klevdavful

Epitome of a good teacher even a newbie can grasps and with enough reps can develope encrypt decrpt skills.

• ### klevdavful

It's not going to give u exactly two because I think the number is prime , so it puts u closest to the number that u should be able to round up.

• ### Disaster

where did you get 11?

• ### Dauphin Guillaume

I miss school so much when I see this kind of topics handled by a great teacher

• ### Luiza Serson

Where did he take 11 from? How did he know?

• ### Sakib Hasan

Man … I would fight to attend his class,,, He is one hell of a good teacher! much appreciated!

• ### Ryan Austin

Can you teach me everything you know before you leave this world?

• ### pk

When he said you gave me D ???

• ### Mohd Asyraaf Syahmi

How do you get 11?

• ### Maloum MMM

The best RSA explaination i have ever seen

<3

• ### iErcan

Soient les plus importants pour moi de me rendre compte que je ne suis pas la seule personne seule qui me demande de me faire rembourser par et qui je n'ai pas eu de réponse à ma demande et je n'ai n'ai pas eu de réponse à

• ### Oliver Shi

I love the enthusiasm!

• ### The Fruit Of All Derps

14 isn't a prime number, so I'm confused as to how you came up with it or how it works, if you could take the time to explain it, I'd really appreciate it.

• ### Prithveen

If I had a lecturer like this guy, I would ace every subject! Great job man!