Asymmetric Encryption and Signing with Public Private Keys
Bob and Alice will only get you so far.
Article at https://coolaj86.com/articles/asymmet...
Without getting deep into math, I paint a picture of specifically how RSA encryption works, it's connection with AES, and how HTTPS and GPG use both.
I also show examples using the OpenSSL commandline tools and ursa in node.js.
It's still pretty high-level, but with sprinkled with some practical details and understanding you may not have had before.
Examples with OpenSSL Node.js