Blockchain (BlCh)

The admin part gives an overview on the lecture content 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 (part 1) of Distributed Systems (DSy) (Slides: HS25-BlCh-01-rep1.pdf). [81min]

The admin part gives an update on the lecture content and challenge task (Slides: HS25-BlCh-02-admin.pdf). 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 is the repetition (part 2) of Distributed Systems (DSy), including the Bitcoin/Blockchain introduction. (Slides: HS25-BlCh-02-rep2.pdf). [75min]

The admin part gives an update on the lecture content and challenge task (Slides: HS25-BlCh-03-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article covers a sophisticated NPM supply chain attack that used worm-like propagation to compromise over 500 packages, targeting cloud credentials on Linux/macOS systems. The next article introduces PrevelteKit, a minimalistic web framework that generates static files at build time for CDN deployment. The third article explains building Docker-like containers from scratch using standard Linux tools and namespace isolation. The cryptocurrency section covers Bitcoin's decline due to ETF outflows and liquidations. The multikernel proposal discusses running multiple Linux kernels on single machines with dedicated CPU cores. The GenAI article argues AI amplifies senior developers rather than democratizing coding. The final article covers Switzerland's successful deposit token proof-of-concept enabling blockchain-based programmable payments using traditional bank deposits (Slides: HS25-BlCh-03-news.pdf). The third video introduces Ethereum and shows how to deploy a smart contract on the Ethereum testnet (Slides: HS25-BlCh-03-ethereum.pdf). The fourth video introduces account abstraction (Slides: HS25-BlCh-03-account-abstraction.pdf). [122min]

The admin part gives an update on the lecture content and challenge task (Slides: HS25-BlCh-04-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article covers a record 22 Tbps DDoS attack by the Aisuru botnet, reinforcing network unreliability. The next discusses Afghanistan's September 2025 internet blackout affecting 43 million people. The third topic presents nine European banks launching a MiCA-compliant euro stablecoin in 2026, though permissioned blockchain choices may hinder adoption. The fourth article announces Cloudflare's NET Dollar stablecoin for AI-driven payments. The final topic examines Circle's reversible USDC transactions, which contradicts blockchain's core immutability principle (Slides: HS25-BlCh-04-news.pdf). The third video introduces Solidity (Slides: HS25-BlCh-04-solidity.pdf). The fourth video shows the ERC 4437 account abstraction on the Ethereum testnet. (Slides: HS25-BlCh-04-account-abstraction.pdf). [136min]

The admin part gives an update on the lecture content and challenge task (Slides: HS25-BlCh-05-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first two articles show self-hosting email is feasible with proper SPF, DKIM, and DMARC configuration. The next article explains consistent hashing, which minimizes data movement when nodes change by using circular mapping. The following article details the AT protocol's URI resolution in Bluesky, which separates user identity from hosting location for portability. The final article describes South Korea's data center fire that destroyed 750,000 civil servants' files with no external backups, demonstrating why redundancy is critical (Slides: HS25-BlCh-05-news.pdf). The third video introduces fungible tokens (Slides: HS25-BlCh-05-tokens-ft.pdf). [53min]

The admin part gives an update on the lecture content and challenge task (Slides: HS25-BlCh-06-admin.pdf). The second video reports on distributed systems and blockchain news. The first article advocates owning your email domain but oversells "full control" when only providing backups. The next discusses self-hosting benefits despite hardware reliability issues. The third exposes Bluesky's centralization problem—despite decentralization claims, alternatives depend on Bluesky's infrastructure, similar to OpenSea's marketplace dominance. The fourth examines how AI assistants enable building small utilities economically, introducing "vibe engineering" as skilled AI-assisted development. The final covers a $192 million Bitcoin short timed minutes before Trump's tariff announcement, linked to BitForex's former CEO, illustrating unpunished manipulation in crypto markets (Slides: HS25-BlCh-06-news.pdf). The third video introduces non-fungible tokens (Slides: HS25-BlCh-06-tokens-nft.pdf). [64min]

The admin part gives an update on the lecture content and the 2nd hand-in of the challenge task (Slides: HS25-BlCh-07-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article examines homelab complexity, showing self-hosting requires handling storage failures and system deadlocks that cloud providers automate. Next, two companies demonstrate infrastructure optimization: one cut cloud costs 76% by migrating to Hetzner, another gained 6x performance by replacing serverless with stateful Go servers to eliminate caching latency. The following article covers Go 1.25's CSRF protection and authentication security tradeoffs. Next is a warning about fake job interview scams distributing malware-infected code to steal cryptocurrency. The penultimate article describes Paxos accidentally minting then burning 300 trillion PYUSD tokens, exposing centralized control risks. The final article reports the DOJ's largest seizure: 15 billion dollars in bitcoin from a Cambodian pig butchering operation (Slides: HS25-BlCh-07-news.pdf). The third video introduces decentralized finance - DeFi (Slides: HS25-BlCh-07-defi.pdf). [91min]

The admin part gives an update on the lecture content (Slides: HS25-BlCh-08-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article examines AWS's 15-hour outage caused by a DynamoDB DNS race condition that cascaded across 113 services affecting over 1,000 platforms. The next topic covers MetaMask's multichain updates adding Bitcoin and Solana support. The third article shows how Idealist.org cut costs from $3,000 to $55 monthly by replacing Heroku with a Hetzner server. The next topic explains CRDTs as coordination-free data structures enabling distributed convergence, with Notion running one of the largest implementations. The fifth article discusses Stalwart's JMAP implementation as a modern JSON-based successor to IMAP. The final article reports Trump's pardon of Binance founder CZ, potentially allowing his return despite his money laundering conviction (Slides: HS25-BlCh-08-news.pdf). The third video introduces decentralized finance - DeFi (Slides: HS25-BlCh-08-dex.pdf). [74min]

The admin part gives an update on the lecture content (Slides: HS25-BlCh-09-admin.pdf). The second video (news) reports on distributed systems and blockchain news. A CTO achieved 2-3x productivity using AI coding tools by directing rather than writing code. The Swiss Army fixed failing IT projects by switching to two-week agile sprints. A company saved $1.2M annually migrating from AWS to bare-metal with better uptime. Azure and AWS both suffered global DNS outages highlighting cloud concentration risks. An EU report revealed submarine cable vulnerabilities with US hyperscalers controlling 90% of transatlantic capacity. A critique of React Server Components showed Next.js performance issues including doubled bandwidth. PostgreSQL benchmarking demonstrated it can replace Kafka for most workloads. NPM was flooded with 100+ malicious packages using hidden remote dependencies, downloaded 86,000+ times. Romania banned Polymarket for unlicensed gambling despite its $2B investment (Slides: HS25-BlCh-09-news.pdf). The third video introduces wallets and seeds (Slides: HS25-BlCh-09-wallets.pdf), and the fourth video discusses decentralized autonomous organizations (DAOs) (Slides: HS25-BlCh-09-dao.pdf). [87min]

The admin part gives an update on the lecture content and the 3rd hand-in of the challenge task (Slides: HS25-BlCh-10-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article demonstrates how URLs can encode complete application state without server-side storage, though practical limits constrain URLs to around 2000 characters. The next article examines Nextcloud's performance issues, revealing 15-20 megabytes of JavaScript creates significant client-side processing costs, especially on weaker devices. The third article addresses data sovereignty concerns where the US CLOUD Act allows American authorities to access Microsoft's European cloud data regardless of physical server location. The final article exposes a cryptocurrency scheme where Stream Finance created stablecoins through recursive minting loops, counting the same $1.9 million collateral multiple times to generate $14.5 million in tokens before a trader lost $93 million (Slides: HS25-BlCh-10-news.pdf). The third video explains hashed time-locked contracts (Slides: HS25-BlCh-10-htlc.pdf), and the fourth video is an interview with Guilherme Machado from Axlabs [91min]

The admin part gives an update over this lecture and shows the exam preparation (Slides: HS25-BlCh-11-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article discusses Bitcoin's drop to $90'000, demonstrating its correlation with traditional markets despite decentralization. The next article examines TCP's reliability mechanisms and congestion control developed after the 1986 collapse. The third article criticizes Spec-Driven Development as Waterfall methodology reborn, advocating iterative development instead. The next topic covers heartbeat mechanisms in distributed systems and their bandwidth-detection tradeoffs. The following article details Prosopo's 90% cost savings migrating from MongoDB Atlas to self-hosted Hetzner servers. The final article reports China accusing the US of orchestrating a $13 billion Bitcoin theft linked to Cambodia-based cryptocurrency scam operations (Slides: HS25-BlCh-11-news.pdf). The third video discusses scaling, layer 2, and payment channels (Slides: HS25-BlCh-11-scaling.pdf). [95min]

The admin part gives an update on the lecture content and details on the upcoming challenge task presentation day (Slides: HS25-BlCh-12-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article demonstrates Google's experimental 130'000-node Kubernetes cluster, showcasing horizontal scaling with 1'000 pod operations per second and architectural improvements like Spanner-based storage and Kueue for job management. The next article explores event sourcing architecture, storing state changes as immutable events combined with CQRS, with trade-offs of 3-5x storage costs. The third article reveals an AWS misconfiguration where 20 terabytes from EC2 to S3 cost over $1'000 due to NAT Gateway routing instead of free VPC Gateway Endpoints. The fourth article discusses Kubernetes as a private cloud on bare-metal hardware, offering predictable costs with tools like Rook and CloudNativePG. The final article covers the Cloudflare outage affecting 20% of websites globally, triggered by a Bot Management feature file exceeding memory limits, illustrating centralization risks in distributed systems (Slides: HS25-BlCh-12-news.pdf). The third video introduces stablecoins (Slides: HS25-BlCh-12-stablecoins.pdf). [78min]

The admin part gives an update on the lecture content and details on the upcoming challenge task presentation day (Slides: HS25-BlCh-13-admin.pdf). The second video (news) reports on distributed systems and blockchain news. The first article covers the shutdown of cryptomixer.io by Swiss and German authorities, seizing 24 million euros in Bitcoin from a mixer that processed 1.3 billion euros since 2016, alongside a five-year prison sentence for a Samourai Wallet founder. Next, hardware reliability issues: SSDs lose data when unpowered (QLC NAND retains only 1-2 years), and Airbus issued emergency directives for 6'000 A320s after solar radiation caused bitflips triggering an uncommanded dive. The SHA1HULUD supply chain attack compromised 1'000+ NPM packages through malicious preinstall scripts stealing credentials. Finally, Clara, a locally-hosted RAG lecture assistant at OST will soon go live for my students in this lecture (Slides: HS25-BlCh-13-news.pdf). [16min]