Technical intro into Ethereum Blockchain Platform, covers blocks, transactions, accounts and smart contract basics.

1. DEJAN RADIĆ
Ethereum Intro

2. Agenda
● Blockchain basics
● Cryptography
● Distributed systems
● Ethereum
● Accounts
● Transactions
● Blocks
● Smart Contracts
● Ethereum Virtual Machine
● Demonstration

3. ● Linked list of blocks
● Blocks chained over hash
values of previous blocks
● Distributed/decentralized
● Immutable
● Secure
● Zero downtime
Blockchain

4. Cryptography
● Asymmetric cryptography
● Public and private keys
● Address derived from public key
● Hash functions – for block linking
Base technologies

5. Base technologies
Distributed systems
● Consensus algorithms
● Gossip protocols
● BFT - Byzantine fault tolerance
● CAP:
●Consistency
●Availability
●Fault tolerance
● FLP Impossibility
● POW – Proof Of Work
● Double spending problem

6. ● Open-source blockchain based platform
● Creator - Vitalik Buterin
● Initial release – July 2015
● License - GPLv3
● Cryptocurrency – Ether (ETH)
● Smart contracts - scripts executed using an
international network of public nodes
Ethereum

7. Ethereum
● Suitable for projects and applications whose capacity is not large enough for building
single purpose blockchain
● Enterprise Ethereum Alliance
● Important acronyms:
○ EIP - Ethereum Improvement Proposal
○ ERC - Ethereum Request for Comments
○ EVM – Ethereum Virtual Machine
○ ENS - Ethereum Name Service

8. ● Cryptocurrency on top of Ethereum Platform
● Symbol - ETH
● Used for paying Gas to miners
● Ensures developers are writing efficient smart contract code
● 60 million ETH sold on presale
● 12 million ETH – development fund (Ethereum Foundation)
Ether currency

9. Overview

10. ● Identified by addresses
● Address is hash value of public key - simplified
● 20 bytes => 160 bits => 40 hex characters
● Externally owned accounts – controlled by private keys
● Contract accounts – controlled by code
● Important properties:
○ Nonce
○ Balance
○ Contract code
○ Storage
Account

11. ● Transaction represents message
signed by externally owned account
that is sent to
● Important properties
○ Recipient
○ Value
○ Signature
○ Data (5 gas per byte)
○ Gas Price & Limit
Transactions

12. Transactions

13. ● 14 seconds between blocks
● 3 ETH block reward for miner
● Hard & soft forks
● Important properties:
○ Parent Hash
○ Timestamp
○ Beneficiary
○ Difficulty
○ Number
○ Gas Used & Gas Limit
Blocks

14. Blocks

15. ● Blockchain based script that facilitates
functionality of a standard contract
● Usually emphasizes financial aspects
● Deployed contract can’t be changed
● EVM – similar to JVM
● Solidity and Viper compiled to bytecode
● OOP manner
● Gas Limit – for both storage and compute
Smart contracts

16. Smart contracts

17. Demonstration

18. CryptoKitties

19. ● Blockgeeks – What is Ethereum?
● ConsenSys - Ethereum: Bitcoin Plus Everything
● Vitalik Buterin - Devcon2: Ethereum in 25 Minutes (YouTube)
● Preethi Kasireddy - How does Ethereum work, anyway?
● Henning Diedrich - Ethereum: Blockchains, Digital Assets, Smart Contracts,
Decentralized Autonomous Organizations
● George Icahn - Ethereum: The Complete Guide To Understanding Ethereum
Further reading
White paper Yellow paper Reading list

20. That’s all folks !!!
Acknowledgements:
Mirko Ilić
Dragan Trivić
Dušan Đukić
Danijela Cvišić
Aleksandar Vukotić