Cryptography
Cryptography is the study of encryption and decryption. Security agencies often hire mathematicians to research new ways to keep their data secure.
One-Time Pads
One Time Pads are the strongest method of encryption. It is the only unbreakable method of encryption. Unfortunately, we cannot use it. Watch the video below on it:
Think about it: What's the problem? Why can't we use OTP?
RSA ALgorithm
The following video explains the RSA Algorithm, which involves modular arithmetic.
Diffie-Hellmen Key Exchange
In order to have a private key, something that's needed in many applications, we use the Diffie Hellmen Key-Exchange. Watch the video below to learn the details.