RSA, DH, and DSA are the asymmetric encryption algorithms which the entire world of modern secure communication rests upon.

Unfortunately, Asymmetric Encryption is often oversimplified as simply being able to "encrypt with one key, and decrypt with the other." But that definition is woefully incomplete.

I recently published a video on each providing a more thorough definition, including a walk through of the math for both RSA and DH, and a practical description of DSA. My goal was to prove how these alrogithms work, so that you aren't just taking my (or anyone else's) word for it.

RSA Algorithm [15:47]

Diffie-Hellman (DH) Key Exchange [6:55]

DSA - Digital Signature Algorithm [5:46]

Hope these help you.

Q: What about Elliptic Curve? ^{Since I'm sure this question will come up}

Elliptic Curve simply uses one of the above algorithms. To explain it more thoroughly would require another video, but for now, I'll simplify it to say EC uses the above three algorithms with different type of values. Instead of using whole numbers (1, 2, 3, ... 501, 502, 503, etc...), EC uses coordinates on a curve to represent values.

If you prefer reading an article (instead of watching videos), I wrote about RSA, DH, and DSA from a practical perspective here:

https://www.practicalnetworking.net/practical-tls/rsa-diffie-hellman-dsa-the-pillars-of-asymmetric-cryptography/

PS: About a year ago, someone posted my Diffie-Hellman infographic to this subreddit (thanks, /u/pjlmaster !). It became the 37th top voted post in this subreddit. The DH videos above is a walk thorough of that infographic. Since that post did so well, I thought this community might also enjoy the videos above. Cheers!