Long before the development of symmetric and asymmetric encryption technologies, an enormously lot has happened in the field of cryptography already. Classical encryption methods have been developed, broken, improved and discarded en masse throughout history.
One of the more interesting technically approaches of the last century was - among others - the German Enigma encryption machine, which was mainly used for secure U-Boot communications. Who knows the history, knows that a team around one of the fathers of modern computer science - Alan Turing - designed and built an electro-mechanical machine in the 40's, with which the Enigma algorithm, which was unbroken until then, could be broken in realistic time - game changer for WWII.
The Enigma is part of many lectures and exercises for CS students, but Angela Zou, Robby Huang & Kathleen Wang from Cornell University got to the technical bottom of not only the Enigma but also the so-called Bomb machine.
The three implemented the Enigma using Verilog and C. Subsequently they realized an FPGA implementation of the Bomb machine, and then tested the decryption with the help of a test program.
The entire project is documented in very much detail, and the code is available on GitHub. Interesting not only for crypto nerds. (I mean the other crypto nerds.)