The document discusses the transition from centralized data systems, exemplified by social media like Facebook, to decentralized applications (dApps) built on blockchain technology. It highlights the drawbacks of centralization, such as economic distortions and lack of user compensation, while proposing solutions such as off-chain transactions and curation models. The text also explains the infrastructure of dApps, including the use of tokens, smart contracts, and oracles to facilitate decentralized interactions and maintain data integrity.

1. DISTRIBUTED
APPLICATIONS
THE WAY TO

2. “
„
– The Guardian
THE WORLD’S MOST VALUABLE
RESOURCE IS NO LONGER OIL,
BUT DATA.

3. “
„
– Adolf Hitler
WHO HAS THE YOUTH, HAS THE
FUTURE

4. BY AGE GROUP
SOCIAL MEDIA USAGE

5. YOU ARE
THE
PRODUCT
YOU ARE NOT THE
CUSTOMER

6. CUSTOMERS PAY FOR SERVICE WITH THEIR PERSONAL
DATAIN THE END HE GETS NOTHING IN RETURN

7. DATA IS CENTRALIZED

8. DRAWBACKS OF CENTRALIZATION
• It distorts the economy.
• Power is concentrated.
• The user has no influence on the use of his data.
• The user is not compensated for his data.

9. BY NO ONE?
WHAT IF FACEBOOK
WAS OWNED

10. BY
EVERYONE?
WHAT IF FACEBOOK
WAS OWNED

11. BLOCKCHAIN
DECENTRALIZED
APPLICATION ON THE

12. WEB 3.0

13. DISTRIBUTED WEB APPLICATIONS
FRONTEND WEB SERVER DATABASE
FRONTEND
SMART-
CONTRACT
BLOCKCHAIN
Classical Web App
Distributed Web App
GAS

14. EXAMPLES OF
DECENTRALIZED
APPS

18. BLOCKCHAIN 2.0 (ETHERUM)
CHALLENGES
• dApps are often still in an alpha stage
• Far too little funds / no revenue model
• Slow: transactions take several minutes
• Expensive: every action costs a few cents
• Requires browser plugins and an ether wallet
• Little audience
• No regulation
• No curation: spam, phishing and illegal content

19. POSSIBLE SOLUTIONS
• Off-chain transactions: more speed, lower costs (e.g. raiden, plasma)
• DAG-Chain: Better scaling (e.g. Cardano)
• Native browser support (e.g. Brave)
• Curation model via incentives (such as Stackoverflow.com)

20. ALL NEW STUFF
BLOCKCHAIN TECHNOLOGIES
Web 2.0 Web 3.0 (dApps)
Skalierbare Server Amazon EC2 Etherum, Truebit
Storage Amazon S3 IPFS/Filecoin, Storj
External data APIs Oracles
Monetisierung Werbung, Daten Tokens
Bezahlung Kreditkarte, TWINT Etherum, Bitcoin

21. BLOCKCHAIN-ARCHITECTURE
DECENTRALIZED APPLICATIONS
BLOCKCHAIN 2.0
STORAGE & CONTENT DELIVERY
SMART CONTRACTS
SERVICE LAYER
DAPP

22. TOKENS

23. “
„
– Jedes Blockchain-Startup
OUR TOKEN WILL GO TO THE MOON!

24. CRYPTO-TOKENS
• Tokens are a virtual currency for a distributed service.
• They can be traded publicly.
• If the service becomes successful, the value of a token increases (or doesn't).
• Each transaction in a dApp costs a certain amount of tokens. However, users can also
receive tokens for certain actions.
• There is a white paper for each token.
• Tokens are first sold in an Initial Coin Offering (ICO).
• The token interface is standardized on the Etherum blockchain (ERC20)

25. IPFS

26. HTTP
• Data is addressed via its position on a server.
• Centralized
• Data can be changed
• Not persistent

27. P2P HYPERMEDIA-PROTOKOLL
INTER-PLANETARY FILE SYSTEM
• Data is addressed via the content (hash)
• Distributed and peer-to-peer
• Built-in versioning
• Fail-safe
• Protection from censorship
• Name server
• Allows decentralized hosting (e.g. Filecoin)

28. ORACLES

29. SMART CONTRACTS CANNOT COMMUNICATE WITH THE OUTSIDE WORLD
THE BLOCKCHAIN IS A CLOSED SYSTEM

30. E.G. A WEATHER APP ON THE ETHERUM BLOCKCHAIN
A DAPP IS EXECUTED ON ALL MINERS
• Each node accessed the weather
API.
• But not at the same time.
• The API response could differ across
nodes.
NODE
NODE
NODE
NODE
WETTER
API

31. E.G. A WEATHER APP ON THE ETHERUM BLOCKCHAIN
A DAPP IS EXECUTED ON ALL MINERS
• The nodes access the weather app
via an oracle.
• The oracle is a special smart contract
that allows side-effects.
• It always returns consistent data.
NODE
NODE
NODE
NODE
WETTER
API
ORAKEL

32. GREAT
AGAIN
MAKE THE WEB

33. DECENTRALIZE
D AGAIN
MAKE THE WEB