Summary

Over the course of this chapter, we introduced the basics of classical cryptography, and you learned how to use encryption techniques from symmetric cryptography with the Caesar cipher or the one-time pad, and from asymmetric cryptography with Diffie-Hellman key exchange.

Then, we turned toward quantum cryptography and learned about quantum key distribution, which is a quantum protocol that facilitates secure key exchange for two parties that do not share any prior information.

Finally, you learned how to implement the entire process of quantum key distribution using Silq. You can now apply your newly acquired knowledge to implement another quantum cryptography process: quantum coin tossing.

In the next and final chapter, you will get an introduction to quantum machine learning.