RSA Algorithm - How does it work? - I'll PROVE it with an Example! -- Cryptography - Practical TLS

Factors of semi prime number 1909 are 23 and 83.

23 * 83 = 1909

The encryption/decryption calculation makes use of the semi-prime. Does this form part of both the private and public keys in practice?

A very clear explanation. Thank you so much for that. :)

First time I have seen public key encryption with an example

23/83. It's actually pretty easy with Excel. SQRT(1909) = 43.6921, so do x=1 to 44 with 1909/x. Since it's semi-prime, only one value (23) will have a whole number answer. Just to check, 23*83=1909 and both are prime. But that's 1909. Doing the same for a 100+ digit number is beyond what Excel can handle. Great video. Thanks!

Great and simple explanation and examples with simple numbers helps to reinforce concept

Well explained....2 and 3 are prime numbers if you multiply you get 6 so is 6 a factor and a semi prime number at the same time?

Thank you! I've wondered about this for a long time. Highly appreciate your simplification and well-executed presentation =]

Impressive!😃

Ed your explanation is truly a blessing ❤❤❤

Thank you :) Completely understood!

Amazing video but I want to ask two questions: How come RSA keys are MUCH bigger with letters like how does it end up being like that? Does that mean using what you said we could code a simple version of RSA like a library?

Awesome! Thank you!!!

The numerical value of the message will never be able to be bigger than the product. How big are usually this numbers in real life usage?

83,23

I know this is a bit late, but I'm just gonna try my luck.
Does anyone know when Encrypting with your private key is beneficial? Since the Public key is known by the public, then your encrypted message can be read by anyone with that key which defeats the whole confidentiality component of Asymmetric Encryption Algorithm.

Excellent video. Thanks very much for explaining it.

1909 = 23 × 83

I just made a python script to get factors of number. Factors for 1909 is 23 and 83

Excellent explanation. Thanks!

Thank you, Very Good

Ive watched a lot of videos to understand rsa but this was the only one that made me understand it! Thanks for the video!

Very clear explanation of RSA that is easy to follow!

That was awesome👏👏

Thank you I am not into math, but I understand this like reading Hello World and understand it heheh!

Can't stop clapping, this was so impressive I might just try to pursue whatever this is as a career

Pam.. Jim and where is Dwight?

thank you

Damn, This is literally very easy. Couldn't able to understand this in my semaster and now after 10 days i have final exams for cryptography. This helped me alot

This is one of the most effective lessons I’ve encountered on RSA🎉

The best and most easiest explanation of the RSA. 🫡

The best teacher

Your formula for the totient is not true for all semi-primes, e.g. it doesn't work for the square of a prime.

Though this video is interesting and well done, it does not prove anything contrary to what it says. It only shows an example where it is working.
This has little to do with a formal proof. A real proof would show that it will work for any possible choice of prime numbers at the first step.

Your skills in instruction are unrivaled anywhere else and helps make us all feel a little less dumb for not understanding other instructor explanations.

I can only reiterate what many people have already said. This is amazing contents! Thank you very much sir!

Best explanation on RSA 🤩. Thank you so much 😇

One of the best RSA videos that I found

Factors of 1909 are 23 and 83. Wasn't that hard to find, because the numbers are still quite small.

clean explanation

amazing work, to take this and make it understandable on the first run through is a trye gift, thanks you.

The best explanation about RSA ever heard. Thank you so much man.😇

Awesome

You are so unique

Hi! Thanks for the very good explanation.
I have one question that I still couldn't figured out. You said that RSA relies on difficulty of factoring semi prime numbers. However, I cannot figure out how knowing the factors could help to find out the private key? If I take your example, we have product (N) 133 and public key (E) 29. Let's say somehow I know the factors (P,Q) 7 and 19. So, how can I calculate the private key (D) 41 out of these numbers 133,29,7,19? Maybe it's too easy but I can't do the math :)
Thanks in advance!

Probably Demonstrate is more suitable term than Prove here. Strictly speaking showing few working examples doesn't mean it always works, ie not a proof.

Another interesting video with interesting maths behind RSA algo... Simple explanation made me to thank Ed for putting this together for everyone... 🙂

2*5=10 which is not a semi prime but even number 🤔 same happens when you multiple any other prime with an even prime (2).