1. SIGCSE Workshop #108 - Programming Smart Contracts in Ethereum Blockchain using Solidity
Debasis Bhattacharya, JD, DBA – UH Maui College, HI
Mohammad Azhar, PhD – CUNY BMCC, NY
Mario Canul – UH Maui College, HI
Saxon Knight – UH Maui College, HI
Rajiv Malkan – Lone Star College, TX
Takashi Sugimura, PhD – UH Maui College, HI
University of Hawaii Maui College
February 27, 2019
Supported by NSF ATE Award #

2. SIGCSE 2019 Blockchain Workshop #108 - Module 2
Agenda
Module 1 - Cryptocurrencies
Bitcoin Basics, Mining, Consensus, Security – (20 minutes)
Module 2 - Ethereum and Blockchain
Ethereum Basics, Cryptography, Wallets, Transactions – (20 minutes)
Module 3 - Smart Contracts
Smart Contracts and Demo – (15 minutes)
Break – (5 minutes)
Lab - Programming a simple Smart Contract using Solidity – (90 minutes)
Module 4 - Distributed Apps (DApps)
Transition to the classroom (30 minutes)
Next Steps…
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SIGCSE 2019 Blockchain Workshop #108 - Module 2

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5. SIGCSE 2019 Blockchain Workshop #108 - Module 2
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SIGCSE 2019 Blockchain Workshop #108 - Module 2

14. Demo – Hello World Smart Contract on Remix – Solidity IDE
pragma solidity >= <0.6.0;
contract Mortal{
address owner;
constructor() public {
owner = msg.sender; }
function die() public {
if(msg.sender == owner)
selfdestruct(msg.sender);
contract Helloworld is Mortal{
string output = "Hello, World!";
function printHello() public view returns (string memory) {
return output;
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SIGCSE 2019 Blockchain Workshop #108 - Module 2

15. SIGCSE 2019 Blockchain Workshop #108 - Module 2
Demo Instructions
Copy the code and paste into Remix at
Since it is the latest compiler, click on Start to compile or (Ctrl-S)
Once compiled, click on Run tab
In Run, make sure Environment is set to JavaScript VM
Click on pink button Deploy under Helloworld
A smart contract Helloworld will be deployed in memory
Click on Helloworld smart contract at bottom of screen (at memory location in blockchain) to access its functions – die and printHello
Click on printHello function to see output “0: string: Hello, World”
Click on die function to remove smart contract from blockchain
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16. SIGCSE 2019 Blockchain Workshop #108 - Module 2
References
Ethereum Overview and Tutorial – Josh Quintal Truffle, 2017
Solidity Tutorial to Smart Contracts – Intro to Smart Contracts
Installing the Solidity Compiler - Using npm/NodeJS, Docker etc.
Code Examples in Solidity – Voting, Blind Auction, Safe Purchase etc.
Solidity Style Guide – Solidity v0.5.4
Ethereum Command Line tools (CLI) – Geth and Eth from Ethereum Network
Ethereum Greeter Smart Contract – Sample tutorial from Ethereum
Truffle Suite Download – Download the Truffle Software
Ganache Suite Download – Download the Ganache Software
Setting up a Pet Shop Dapp – Truffle Tutorial
Building React Native Dapps – Truffle Tutorial with Drizzle v1.3+
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SIGCSE 2019 Blockchain Workshop #108 - Module 2