Not to be used for anything but educationaĺ purposes as simplified DES is not secure.
It shows the process in generating keys and the process of encrypting and decrypting.
For description of the encryption technic see e.g.:
https://www.youtube.com/watch?v=dRP1FAf4uNw&list=PLvifRcqOOwF9yDamCOXtD5O3fA085X6mP&index=6
Or in this PDF:
https://sandilands.info/sgordon/teaching/reports/simplified-des-example.pdf
See test.js
MIT © Dennis Iversen