Ethereum is an open software platform based on blockchain technology that enables developers to build and deploy decentralized applications. Ethereum is a distributed public blockchain network. While the Bitcoin blockchain is used to track ownership of digital currency (bitcoins), the Ethereum blockchain focuses on running the programming code of any decentralized application. Ether is a cryptocurrency whose blockchain is generated by the Ethereum platform. Ether can be transferred between accounts and used to compensate participant mining nodes for computations performed.

1. Introduction to Ethereum,
Solidity & DApps
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By: Vishal Sahu & Vijay Shukla

2. Agenda
● Introduction
● Ethereum
● Installation
● Ethereum basics
● Geth
● Web3
● Solidity
● Smart Contracts
● Dapps
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3. Ethereum Introduction
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Ethereum is an open software platform based on blockchain technology that enables developers to
build and deploy decentralized applications.
Ethereum is a distributed public blockchain network.
While the Bitcoin blockchain is used to track ownership of digital currency (bitcoins), the Ethereum
blockchain focuses on running the programming code of any decentralized application.
Ether is a cryptocurrency whose blockchain is generated by the Ethereum platform. Ether can be
transferred between accounts and used to compensate participant mining nodes for computations
performed.

4. History
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Ethereum was proposed in late 2013 by Vitalik
Buterin, a cryptocurrency researcher and
programmer.
Development was funded by an online
crowdsale that took place between July and
August 2014.
The system went live on 30 July 2015, with 11.9
million coins "premined" for the crowdsale.
This accounts for about 13 percent of the total
circulating supply.

5. Ethereum Installation
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sudo apt-get install software-properties-common
sudo add-apt-repository -y ppa:ethereum/ethereum
sudo apt-get update
sudo apt-get install ethereum
sudo apt-get install solc

6. Geth & Ethereum Command Line
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● It is implemented in Go language.
● By installing and running geth, you can take part in the ethereum frontier
network.
● Mine Ether
● Transfer fund between different addresses.
● Create smart contract and deploy it.
● Explore entire block history.
● And much more.

7. Geth Commands
● Use geth command to open console.
● geth --datadir [folder_name] --ethash.dagdir [dag_dir] init
[genesis_location]
● By default it runs on 8545 port, but you can change it by using --rpcport
[port_number].

8. Genesis Block
{
"nonce": "0xdeadbeefdeadbeef",
"timestamp": "0x00",
"parentHash":
"0x0000000000000000000000000000000000000000000000000000000000000000",
"extraData": "0x686f727365",
"gasLimit": "0x08000000",
"difficulty": "0x0400",
"mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
"coinbase": "0x3333333333333333333333333333333333333333",
"alloc": { },
"config": {
"homesteadBlock": 0,
"eip155Block": 0,
"eip158Block": 0
},
}

9. What Geth can do?
● Create a node
● Create an Account
● Check Account Balance
● Unlock Account
● Start Mining (earn ether)
● Create more accounts
● Transfer funds between them
● Create more nodes
● Add Peers
● Attach More Console
● Contract Creation
● Deploy Contract
● Interact with Contract

11. ● Smart Contract is just a phrase used to describe computer code that can facilitate the exchange
of money, content, property, shares, or anything of value.
● When running on the blockchain a smart contract becomes like a self-operating computer
program that automatically executes when specific conditions are met.
● Because smart contracts run on the blockchain, they run exactly as programmed without any
possibility of censorship, downtime, fraud or third party interference
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Smart Contracts

12. ● Solidity is a contract-oriented, high-level language for implementing smart
contracts.
● It was influenced by C++, Python and JavaScript and is designed to target
the Ethereum Virtual Machine (EVM).
● Solidity is statically typed, supports inheritance, libraries and complex
user-defined types among other features.
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Solidity

13. pragma solidity ^0.4.0;
contract Counter {
int private count = 0;
function incrementCounter() public {
count += 1;
}
function decrementCounter() public {
count -= 1;
}
function getCount() public constant returns (int) {
return count;
}
}
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Smart Contracts Sample

15. ● A DApp has its backend code running on decentralized peer-to-peer
network.
● A DApp can have frontend code and user interfaces written in any
language (like any other app) that can makes call to its backend.
● Frontend(HTML+CSS+JS) Web page + Backend(Solidity Smart Contract)
Programing Code + Server(TestRPC) Private Blockchain/Dummy Network
on Ethereum Platform.
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DApp (Decentralised App)

16. 16

17. ● Immutability – A third party cannot make any changes to data.
● Corruption & tamper proof – Apps are based on a network formed
around the principle of consensus, making censorship impossible.
● Secure – With no central point of failure and secured using cryptography,
applications are well protected against hacking attacks and fraudulent
activities.
● Zero downtime – Apps never go down and can never be switched off.
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DApps Advantages

18. CryptoCities
CryptoKitties

22. 22
Questions?

24. 1. https://blockgeeks.com/guides/smart-contracts/
2. https://github.com/ethereum/wiki/wiki/JSON-RPC
3. https://github.com/ethereum/go-ethereum/wiki/Command-Line-Options
4. https://github.com/ethereum/web3.js
5. https://github.com/ethereum/wiki/wiki/JavaScript-API
6. https://www.stateofthedapps.com/
7. https://medium.com/taipei-ethereum-meetup/beginners-guide-to-ethereum-3-explain-the-ge
nesis-file-and-use-it-to-customize-your-blockchain-552eb6265145
8. https://arvanaghi.com/blog/explaining-the-genesis-block-in-ethereum/
9. https://medium.com/crypto-currently/build-your-first-smart-contract-fc36a8ff50ca
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References