The DES algorithm have played an important role in the developement of the Cryptography algorithms (Read more on Wikipedia). This Verilog code implements a synthesizable unit for this algorithm.
Create a new project in your desired synthesis or simulation tool, and add all ".v" files to your project. Remember to choose "DES_Encryption.v" as the top-level module. The project is tested on Altera Quartus Prime Lite Edition v16.1.