260035 VU Applied (Quantum-) Cryptography: Codes and how (not) to break them with Quantum Computers (2023W)

Cryptography is the scientific study of techniques for securing digital information, transaction and distributed computations. Any modern communication system (E-Mail, Web-Browsing, Messenging, ...) that claims to be "secure" builds upon the security of cryptographic protocols and the hardness of certain mathematical problems. Although still widely used and studied, the dominant position of the famous RSA algorithm begins to crumble for several reasons: First, to stay secure, its key sizes had to be adjusted regularly, making it inpracticable for use cases such as the Internet of Things. Second, the growing success in the development of Quantum Computers put a serious threat on the use of RSA, as it practicable breaks its hardness assumptions.

This lecture will give an introduction to state-of-the-art cryptography, but will also introduce modern and future techniques which are under active research:
- Goals of Security, Definitions of Trust
- Symmetric and asymmetric cryptography
- Threats to modern cryptography, especially. Quantum Computers
- Post-Quantum Cryptography
- Quantum Cryptography

The lectures will be complemented with exercises, that feature
- Pen-and-Paper calculation
- Programming in Python
- Graphical Proofs