Blockchain (BlCh)
Important dates: (always check https://unterricht.ost.ch)
- Lecture dates: 15.09.2025 - 15.12.2025
Topics / Dates
The lectures will be pre-recorded and will up uploaded before the lecture on Monday at 13:10. The length of the videos will be ~60 minutes (2 x 30 min. lectures) divided into segments. The news segment (~10 min) will cover news around the topics blockchain and distributed systems and are not part of the exam. It should serve as on overview of current topics in this field.
| Nr | Date | Topics |
|---|---|---|
| 01 | 15.09.2025 | Admin (lecture and challenge task), Repetition DSy (part 1) - no exercises |
| 02 | 22.09.2025 | Repetition DSy (part 2), Introduction Blockchain |
| 03 | 29.09.2025 | Ethereum Components / Architecture, Account Abstraction |
| 04 | 06.10.2025 | 1st hand-in, Solidity |
| 05 | 13.10.2025 | DeFi, DEX |
| 06 | 20.10.2025 | DAO, Fungible Tokens, Non-Fungible Tokens |
| 07 | 27.10.2025 | 2nd hand-in, Wallets and Seed Phrases, POAP |
| 08 | 03.11.2025 | HTLCs, Cross-chain Atomic Swaps, Payment Channels |
| 09 | 10.11.2025 | Algorithms/Mechanisms for Fully Distributed Systems |
| 10 | 17.11.2025 | 3rd hand-in, Guest |
| 11 | 24.11.2025 | Ethereum Layer 2, Stablecoins |
| 12 | 01.12.2025 | Exam Preparation |
| 13 | 08.12.2025 | Final hand-in, Challenge Task Presentations |
| 14 | 15.12.2025 | Q&A and Challenge Task Award Winner Announcement - no exercises |
(those are preliminary topics, may be subject to change)
Online/Offline Lectures & Exercises
I will be present in the lecture room 1.257 from 13:10 - 18:40. In the lecture, I will give a brief summary of the video, and if you have not watched the lectures, you can watch it in the lecture (13:10 - 14:50). During exercises (15:10 - 18:40), you can work on your blockchain project (challenge task). You do not need to be present on Monday, but it is highly recommended to discuss your issues and problems with the challenge task with the lecturer. On request, you can also join the exercises remotely via MS Teams.
The online lectures and PDFs can be accessed from outside the OST network (also on YouTube), the exercise and admin material only with VPN.
Lecture
Lecture 1
The admin part gives an overview over this lecture and presents the challenge task for this course (Slides: HS25-BlCh-01-admin.pdf). The weekly news summary covers four articles. The first article covers undersea cable cuts in the Red Sea that disrupted global internet connectivity, demonstrating hardware failure inevitability in distributed systems. The next article discusses Switzerland's launch of Apertus, an open-source multilingual language model representing sovereign AI infrastructure development. The third topic examines Stripe's Tempo blockchain for stablecoin payments, emphasizing the importance of truly permissionless networks over private implementations. The final article covers World Liberty Financial's token freezing controversy, illustrating the contradiction between blockchain's decentralized promises and centralized control mechanisms. (Slides: HS25-BlCh-01-news.pdf). The third video starts with the repetition of Distributed Systems (DSy) (Slides: HS25-BlCh-01-rep1.pdf). [81min]
Lecture 2
The admin part ... The second video (news) reports on distributed systems and blockchain news. The first article covers a supply chain attack where compromised NPM maintainers injected crypto-stealing malware into popular packages. The next article shows WSL2 delivering 87% of bare metal performance with I/O slowdowns. The third topic details SwissBorg's $41.5 million loss through their staking partner's compromised API. The fourth article discusses NGINX's new built-in SSL certificate management. The final article mentions PayPal's cryptocurrency payment integration. (Slides: HS25-BlCh-02-news.pdf). The third video ... [XYmin]
Challenge Task HS 2025
This semester's challenge task (CT) is the design and implementation of a gasless application using account abstraction (we will talk in the lecture what account abstraction is). Students demonstrate how users can interact with blockchain applications without owning or paying gas fees. This could be an application where users: vote on governance proposals without needing gas fees, mint and trade NFTs while the platform sponsors all transaction costs, play blockchain games with in-game actions sponsored by the game developer, participate in DeFi (staking, swapping, lending) without gas fee barriers, complete online courses and earn certificates/tokens gaslessly, ...
- Your app must include a simple frontend (e.g., HTML, Vue, React, Svelte, ...)
- Gasless transaction user interface - users never see or pay gas fees
- Your app must run on a public blockchain (e.g., Ethereum, Solana, Sui, ...)
- Can use EVM chains with ERC-4337 OR chains with native account abstraction
- Gasless transactions must work on chosen platform
- Your app needs to demonstrate gasless user experience
- Platform sponsors transaction costs through account abstraction
Requirements
All requirements below must be met in order to pass this lecture.
- A working prototype demonstrating gasless user interactions
- Use latest stable releases of chosen libraries and frameworks
- Interaction with a public blockchain (can be testnet)
- At least 2 participants need to be involved.
- Gasless transaction implementation using account abstraction
- Status and process need to be shown in the frontend
- The solution may use existing libraries and code, but those must open software software.
Deliverables
- 06.10.2025, 23:59 (CET) first hand-in of your initial plan and project idea. Invitation to github/gitlab repository.
- 27.10.2025, 23:59 (CET) second hand-in of your initial version of your challenge task and current progress (initial state, does not need to run).
- 17.11.2025, 23:59 (CET) third hand-in of your current progress (what works, what is still open).
- Final hand-in: 08.12.2025, 23:59 (CET) - infrastructure documentation (Readme.md or can be slides) and the source code (github/gitlab or similar) via invite or email to thomas.bocek-at-ost.ch. The code and configuration should be easy to read and/or well documented. For the presentation, you should show the architecture, components, and design decisions in 10-15 min, a demo in 5-10 min, and the Q&A will be 5-10 min. After your presentation, you need to hand in your PDF presentation.
You are allowed to use any language, framework, and platforms. However, the supervisors are familiar with those: Golang, Java, JavaScript/TypeScript, Ethereum, Sui, Bitcoin, Linux.
Groups
There will be groups of 2-3 for the challenge task. During the challenge task, the group shall meet every week during exercise hours to work on the task and discuss the next steps. The groups shall utilize their homework times to work on the challenge task, besides the exercise time slots. The groups shall determine and set-up an internal project plan and shall distribute the workload so that each group member gets a fair load of work. Group results will be only accessible via VPN.
| Nr | Name 1 | Name 2 | Name 3 | Project |
|---|---|---|---|---|
| 01 | Diego F. | Pietro L. | ? | |
| 02 | Arnel V. | Fabio G. | ||
| 03 | Silvan L. | Doriano P. | ||
| 04 | Stefanie J. | Mona P. | Laura T. | |
| 05 | Nico H. | Baru B. | Etienne K. | |
| 06 | Timo S. | Sven E. | ||
| 07 | Jovin R. | Lenny M. |