BTI 4202, FS 2025

General information

The course will primarily be taught in English or German by Christian Grothoff, but some lectures will be covered by other lecturers. There will be a final written exam. The date and location of the final exam is yet to be determined by the department. There is a Git repository for the course at https://gitlab.ti.bfh.ch/teaching/bti4202/fs25.

If you have any questions, you can contact me at any time: Christian Grothoff, in Biel, Höheweg 80, Raum N.474.

Content

The lecture will cover the following topics:

• Introductory overview on IT security
• Symmetric encryption and secure channels
• Blockchains
• Shamir secret sharing
• Symmetric key management
• Discussion of selected vulnerabilities and attacks on cryptosystems and real-world deployments
• Certificates, especially X.509
• Centralized and decentralized Public key infrastructures
• Security in distributed systems
• Secure channels: TLS, forward secrecy, future secrecy, repudiation
• Blind signatures
• Anonymity and anonymous digital cash

21.2.2025: Introduction to Computer Security (Part I)

Preparation

• Why key generation matters

Materials

• Slides

Further reading

• Why Tolkien hated Dune
• Virtue ethics
• JTRIG
• Perfectly legal
• Goebels
• Advanced Persistent Threat

28.2.2025: Introduction to Computer Security (Part II)

Materials

• Slides

Further reading

• Skynet
• Tay II
• Tay III
• Hackig back
• Communication in a world of pervasive surveillance, Chapter 4
• AI will cure cancer
• AI's "human in the loop" isn't

07.3.2025: BTI 4201: Definitions and Terminology, Classical ciphers

14.3.2025: BTI 4201: Pseudo-Random Number Generators

21.3.2025: BTI 4201: Public-key encryption (RSA, ElGamal)

28.3.2025: Distributed Systems

Slides

• Slides

Further reading

• A Thorough Introduction to Distributed Systems

4.4.2025: Availability & Key Management

Materials

• Slides: Availability
• Slides: Key management

Exercises

• Availability exercise
• Key management exercise

Further reading

• Postgresql
• GNU Anastasis
• SLAP and FLOP

11.4.2024: Blockchains & Secure Integration

Materials

• Blockchain Slides
• Integration Slides

Exercises

• Blockchain exercise
• Integration exercise
• Code for crypto exercise

Further reading

• Tether
• Applications
• Blochains, NFT and DeFi
• Accelerando
• The deep links crash course
• sPACE Attack: Spoofing eID's Password Authenticated Connection Establishment

18.4.2025: No lecture

No lecture.

25.4.2025: Secure Channels

Preparation

• Intercepting Mobile Communications: The Insecurity of 802.11

Materials

• Slides

Further reading

• Symmetric Encryption by Mihir Bellare and Phillip Rogaway
• Authenticated Encryption: Combining Authentication with Encryption to get IND-CCA (by Nick Hopper)
• Mailto Me Your Secrets
• How is SSL hopelessly broken? Let us count the ways

2.5.2024: Certificates and trust (X.509)

Materials

• Slides

Further reading

• MD5 considered harmful today

9.5.2025: Centralized public-key infrastructures

Materials

• Folien

16.5.2025: Decentralized public-key infrastructures

Materials

• Slides

Exercises

• DPKI exercise

Further reading

• LSD 0001
• LSD 0003
• HACIENDA
• Treasure Map
• Stellar

Note

Afternoon is also BTI 4202: "Identification protocols"!

23.5.2024: Anonymity

Materials

• Slides

Exercises

• Anonymity exercise

Further reading

• Attacks on Tor
• Panoramix

Note

Afternoon is also BTI 4202: "E-Voting"!

30.5.2025: Auffahrt: No lecture

6.6.2024: Blind Signatures & GNU Taler (morning and afternoon!)

Materials

• Slides

Exercises

• Blind Signatures exercise
• rsa.py

Further reading

• IETF PrivacyPass WG
• Adding Schnorr's Blind Signature in Taler
• taler.net
• age restrictions