To start the project:

open cmd prompt and first start Approch2.py from Server/Approches dir

open another cmd prompt then start Server.py from Server dir

then open third cmd prompt and start Client.py

once you start client, it will ask you to type url

After that to verify the database just go into database folder and unUsedkeys.txt and usedKeys.txt would have been created.

The output of approch2 explains why the unUsedKeys.txt is present there.