Thanks again for posting the cryptographic question, Rob Kudyba!
Original post: https://www.facebook.com/groups/ThorTeaches/permalink/2498603593528451/

• https://en.wikipedia.org/wiki/Feistel_cipher
• https://en.wikipedia.org/wiki/Data_Encryption_Standard
• https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
• https://en.wikipedia.org/wiki/Twofish
• https://en.wikipedia.org/wiki/Blowfish_(cipher)

Source: Wikipedia

Feistel Network

DES (Data Encryption Standard)

AES (Advanced Encryption Standard/Rijndael)

Twofish

Blowfish