Programming Challenges - 5 - RSA Encryption (Python)

In this video, we go through the RSA Asymmetric Key Encryption algorithm first with pen and paper then through its implementation in Python. I used Python due to its natural, built-in big number libraries.

Includes random key generation with large prime numbers.

Time Stamps:
• Explanation, pen/paper example: 0:00 - 25:52
• Python implementation: 25:52 - 1:13:33

Mathematical concepts covered: one-way function, modular exponentiation, modular multiplicative inverse, extended euclidean algorithm, prime numbers, rabin-miller

[mohamadabyannaufal]

Thank you! now I realize that RSA is hard to implementation in code, and thanks for your dog that make your tutorial become fun :D

[JJ-lqlg]

great video, helped me iron out a few problems in my own attempt

[shithighandwatch]

Dude you the best on gGod, Big Congrats!!!! Ya Deserve it

[MyAssoom]

is it possible for the ( p & q & plain text ) to be inputs that the user can insert to the algorithm?

[LegendaCarty]

Hey, great and clear video, thank you very much! :) One question: Let's say we have two users. Person one who knows the public key and person two with public and private key. Does person one need to know the value of N (modulus of q and p) in order to encrypt the message he wants to send to person two, or is there a way to encrypt the message with only the public key? I am implementing this in my web apps that communicates together and I'm wondering if N is needed in encryption and IF it is needed, what would be the safest option to share the N. I don't like hard coding values but is that only way of doing it? I have done some research and found out that it wouldn't be optimal that N is shared like public key, since when you know the modulus of q*p you can solve the values of q and p and that's not what we want. Still I want to say, excellent video!

[ayush]

How did you get the equation `1 = (37)(13) - (4)(120)` in *Back Substitution*? How did it imply that `37` is *d*?

[gajahnegara]

how about..i wanna input p, q, private key by manual?

[nehasingh]

Video is great, Can you share the code!

[fnamelname]

105 to the power of 13 (mod 143) = 40. Right?

>>> 105 ** 13 % 143
40
>>>