Introduction to blockchain technology and its applications
- 1. GITATHON 1.0 Unit-1 Introduction to blockchain technology
- 2. Index • THEORY: Introduction to Blockchain Technology , History and evolution of Blockchain , Key concepts: decentralization, consensus mechanisms - cryptographic hashing - Types of Blockchains , Public vs. private blockchains , Permissioned vs. permissionless blockchains , Hybrid blockchains - Use Cases and Applications of Blockchain , Cryptocurrencies and digital assets , Smart contracts and decentralized applications (DApps) , Supply chain management, healthcare, finance, etc. • PROGRAM : Solidity: Introduction to Solidity - Syntax and Data Types - Variables and Data Structures - Functions and Function Modifiers, Smart Contracts Development - Writing simple smart contracts - Events and Error Handling - Introduction to Remix IDE • PRACTICAL: Solidity Syntax and Data Types - Smart Contract Development with Remix IDE Experiment 1: Write a Solidity contract that defines variables of different data types (uint, string, address, etc.) and performs basic operations on them, such as arithmetic operations and concatenation. Experiment 2: Develop a simple smart contract using Remix IDE that implements a basic voting system. Deploy the contract on a local Ethereum test network using Remix and interact with it through the Remix interface.
- 3. Introduction • Blockchain technology, originally introduced through the creation of Bitcoin in 2008 by an anonymous person or group of people using the pseudonym Satoshi Nakamoto, has since evolved into a revolutionary concept with far-reaching implications across various industries. At its core, blockchain is a decentralized, distributed ledger technology that enables secure and transparent peer-to-peer transactions without the need for intermediaries.
- 4. Key concepts of blockchain 1.Decentralization: Blockchain operates on a decentralized network of computers (nodes), where each node stores a copy of the entire blockchain. This decentralization ensures that there is no single point of failure, making the system more resilient and tamper-resistant. 2.Cryptography: Cryptography is used to secure the transactions and control the creation of new units. It ensures that only authorized parties can access and modify the data on the blockchain. Public and private cryptographic keys are used to authenticate identities and validate transactions. 3.Immutability: Once recorded on the blockchain, transactions cannot be altered or deleted. This immutability ensures the integrity of the data and provides a reliable record of transactions. 4.Consensus Mechanisms: Blockchain networks rely on consensus mechanisms to validate and confirm transactions. Different consensus algorithms, such as Proof of Work (PoW) and Proof of Stake (PoS), govern how nodes agree on the validity of transactions and maintain the integrity of the blockchain.
- 5. Types of Blockchain • Public Blockchain A public blockchain is one where anyone is free to join and participate in the core activities of the blockchain network. Anyone can read, write, and audit the ongoing activities on a public blockchain network, which helps achieve the self- governed, decentralized nature often touted when blockchain is discussed Advantages and disadvantages A public network operates on an incentivizing scheme that encourages new participants to join and keep the network agile. Public blockchains offer a particularly valuable solution from the point of view of a truly decentralized, democratized, and authority-free operation. The primary disadvantage to secured public blockchains is the heavy energy consumption required to maintain them. The concern is a consensus mechanism that requires participants to compete to validate the information and receive a reward for letting the network use their processing power.
- 6. Private blockchain • Participants can join a private blockchain network only through an invitation where their identity or other required information is authentic and verified. The validation is done by the network operator(s) or by a clearly defined set protocol implemented by the network through smart contracts or other automated approval methods. • Advantages and disadvantages A private blockchain is not decentralized. It is a distributed ledger that operates as a closed database secured with cryptographic concepts and the organization's needs. Only those with permission can run a full node, make transactions, or validate/authenticate the blockchain changes. While purposefully designed for enterprise applications, private blockchains lose out on many of the valuable attributes of permissionless systems simply because they are not widely applicable. They are instead built to accomplish specific tasks and functions. In this respect, private blockchains are susceptible to data breaches and other security threats.
- 8. Hybrid Blockchain • A hybrid blockchain combines the features of both public and private blockchains, offering a flexible and customizable approach to meet the diverse needs of businesses and organizations. In a hybrid blockchain, certain data and transactions are accessible to the public, while others are restricted to authorized participants. • Key Characteristics of Hybrid Blockchain: • 1Public/Private Integration: Hybrid blockchains allow for the integration of public and private networks, enabling organizations to leverage the benefits of both models. This integration facilitates interoperability and data sharing while maintaining privacy and control. • 2.Customization: Organizations can customize the level of decentralization, privacy, and accessibility according to their specific requirements. This flexibility makes hybrid blockchains suitable for a wide range of applications, from supply chain management to financial services. • 3.Scalability: Hybrid blockchains can scale more efficiently than traditional public blockchains, as they can offload certain transactions to private networks while still benefiting from the security and transparency of the public blockchain.
- 9. Use Cases • Blockchain can also be used to reduce fraud and other trust-related issues in digital ad buying. Blockchain has a wide range of applications in healthcare, including improving payment processing, electronic medical records, provider directories, and data security and exchange. On a blockchain-based platform, artists can upload original works, self-publish, control licensing options, and manage distributions. • 1. Money transfers The original concept behind the invention of blockchain technology is still a great application. Money transfers using blockchain can be less expensive and faster than using existing money transfer services. This is especially true of cross-border transactions, which are often slow and expensive • 2. Financial exchanges Many companies have popped up over the past few years offering decentralized cryptocurrency exchanges. Using blockchain for exchanges allows for faster and less expensive transactions • 3. Insurance Using smart contracts on a blockchain can provide greater transparency for customers and insurance providers. Recording all claims on a blockchain would keep customers from making duplicate claims for the same event. • 4.Voting If personal identity information is held on a blockchain, that puts us just one step away from also being able to vote using blockchain technology • 5.Non-fungible tokens Non-fungible tokens, or NFTs, are commonly thought of as ways to own the rights to digital art. Since the blockchain prevents data from existing in two places, putting an NFT on the blockchain guarantees that only a single copy of a piece of digital art exists
- 10. Applications
- 11. CRYPTOCURRENCY AND DIGITAL ASSETS • Cryptocurrency is like digital money that exists only on computers and is not controlled by any government or bank. It's made possible by a technology called blockchain, which keeps track of all transactions securely. People can use cryptocurrency to buy things online, invest, or send money to others, just like regular money, but it's all digital and decentralized. Popular examples include Bitcoin and Ethereum. • Digital assets refer to any form of content or data that exists in a digital format and has economic value. These assets can include various types of files such as images, videos, audio recordings, documents, software, and even virtual currencies like cryptocurrencies. Digital assets can be owned, bought, sold, and traded similarly to physical assets, but they exist solely in digital form and are often stored or transferred electronically. Examples of digital assets include digital art, music downloads, e-books, domain names, online subscriptions, and more. Digital assets like cryptocurrencies, NFTs and other tokens are past "emerging" - they're here to stay
- 12. Smart Contracts • Blockchain technology has a wide range of use cases and applications across various industries. Here are some notable ones: Smart Contracts- Blockchain enables the execution of smart contracts, which are selfexecuting contracts with the terms of the agreement directly written into code. These contracts automatically enforce and execute themselves when predefined conditions are met, without the need for intermediaries. A smart contract is an electronic contract that can be executed automatically. Smart contracts use blockchain technology and can be programmed to execute when-and only when- specific conditions are met. Smart contracts, once published to a blockchain, are immutable and always visible to all participants in the blockchain. • These are some of the use cases for smart contracts: • Automate workflows • Record property ownership • Make elections more efficient • Reduce or eliminate legal fees • Reduce insurance fraud • Protect sensitive medical information
- 13. Decentralized Applications • If you understand smart contracts, it's easier to understand decentralized applications (dApps). Decentralized apps frequently use blockchain technology in two ways: • To support features. Decentralized apps can use smart contracts to support their core features. • To decentralize control. Creators of a dApp may deploy the entire set of code to the blockchain, totally relinquishing control to the community that uses it. No single individual controls this type of dApp, including it's developer #How decentralized applications work How can a project function if its management is completely decentralized? An app with decentralized governance uses a predetermined consensus mechanism, such as proof of stake or proof of work, to create a technologically automated process for decision making. Examples of decentralized apps: • BitTorrent: Perhaps among the best-known dApp platforms, this decentralized application supports peer-to-peer file sharing. BitTorrent is integrated with the TRON (TRX) blockchain. • Aave: Aave is a decentralized liquidity platform that uses blockchain-based protocols to operate. Aave users can lend, borrow, and stake cryptocurrency, plus earn interest on deposits
- 14. Supply Chain Management • Supply chain management using blockchain involves using blockchain technology to enhance the efficiency, transparency, and security of supply chain processes. Here's how it works: • 1. Transparency-Blockchain provides a transparent and immutable ledger where all transactions and events related to the supply chain are recorded. Each participant in the supply chain, such as manufacturers, suppliers, distributors, and retailers, can view and verify the information recorded on the blockchain, leading to greater transparency and trust. • 2. Traceability- With blockchain, every step of the supply chain can be traced back to its origin. Each product or component is assigned a unique digital identifier, which is recorded on the blockchain along with relevant information such as its source, manufacturing date, location, and ownership history. This enables quick and accurate traceability in case of recalls, quality issues, or compliance requirements. • 3. Security - Blockchain's decentralized and cryptographic nature ensures that data stored on the blockchain is tamper-proof and resistant to unauthorized alterations. This enhances the security of sensitive supply chain information, such as product specifications, contracts, and payment records, reducing the risk of fraud, counterfeiting, and data breaches. • 4. Efficiency- By streamlining data sharing and eliminating intermediaries, blockchain can improve the efficiency of supply chain processes. Smart contracts, which are self-executing contracts with predefined rules encoded on the blockchain, can automate and enforce agreements between parties, such as payment terms, delivery schedules, and compliance requirements, reducing paperwork, delays, and disputes. • 5.Collaboration- Blockchain facilitates greater collaboration and coordination among supply chain participants by providing a single source of truth that is accessible to all authorized parties in real-time. This enables better communication, coordination, and decision- making across the entire supply chain network, leading to improved inventory management, production planning, and customer service.
- 15. In Healthcare Healthcare in blockchain involves using blockchain technology to improve various aspects of the healthcare industry, including patient data management, interoperability, drug traceability, and medical research. Here's how it works: 1.Patient Data Management- Blockchain enables secure and decentralized storage of patient health records. Each patient has their own encrypted digital identity on the blockchain, and their medical records are linked to this identity. Patients have control over who can access their data, ensuring privacy and security. 2. Interoperability- Blockchain facilitates the exchange of healthcare data between different healthcare providers, systems, and organizations. It allows for seamless sharing of patient information while maintaining data integrity and security. This interoperability improves care coordination and enables better healthcare outcomes. 3. Drug Traceability- Blockchain can be used to track the entire lifecycle of pharmaceutical products, from manufacturing to distribution to consumption. Each drug is assigned a unique digital identifier, and its journey through the supply chain is recorded on the blockchain. This ensures transparency, authenticity, and safety of medications, helping to prevent counterfeit drugs and improve patient safety
- 16. Healthcare
- 17. In Finance • Finance in blockchain means using blockchain technology to make financial transactions faster, more secure, and more transparent. Here's how it works: • 1. Fast Transactions- Blockchain allows people to send money or make transactions directly to each other without needing a bank or other middlemen. Transactions can happen quickly because blockchain operates 24/7 and doesn't depend on traditional banking hours. • 2. Secure Transactions- Blockchain uses cryptography to secure transactions, making them almost impossible to tamper with. Each transaction is recorded in a digital ledger that's distributed across many computers, so even if one computer fails or gets hacked, the information remains safe and accessible. • 3. Transparency- Blockchain provides a transparent record of all transactions. Anyone can view the transaction history, but personal information remains private and encrypted. This transparency helps build trust in financial transactions and reduces the risk of fraud. • 4.Decentralization- Blockchain is decentralized, meaning there's no single authority or institution controlling it. Instead, transactions are verified and recorded by a network of computers, making it resilient to censorship and manipulation.
- 18. Solidity • Introduction to Solidity • Solidity is a high-level programming language used for writing smart contracts on blockchain platforms, notably Ethereum. Introduced in 2014 by Gavin Wood, it's specifically designed for creating decentralized applications (DApps) and executing smart contracts. Solidity resembles JavaScript and is known for its simplicity and suitability for blockchain development. It allows developers to define data structures, functions, and logic to govern how smart contracts behave on the blockchain. Smart contracts written in Solidity are executed on the Ethereum Virtual Machine (EVM), enabling trustless and immutable execution of code.
- 19. Syntax and Data Types • Boolean :The Boolean data type returns ‘1' when the condition is true and ‘0' when it is false, depending on the status of the condition. • Integer : You can sign or unsign integer values in Solidity. It also supports runtime exceptions and the ‘uint8' and ‘uint256' keywords. • String :Single or double quotes can denote a string. • Modifier :Before executing the code for a smart contract, a modifier often verifies that any condition is rational. • Array :The syntax of Solidity programming is like that of other OOP languages, and it supports both single and multidimensional arrays.
- 20. Variables • Solidity supports three types of variables. • State Variables − Variables whose values are permanently stored in a contract storage. • Local Variables − Variables whose values are present till function is executing. • Global Variables − Special variables exists in the global namespace used to get information about the blockchain. • Solidity is a statically typed language, which means that the state or local variable type needs to be specified during declaration. Each declared variable always have a default value based on its type. There is no concept of "undefined" or "null".
- 21. Structure • There are different basic data types available in Solidity such as uint(unsigned Integers, bool, array, and string. But as a blockchain developer, you may need a flexible data type that you can define by yourself. A struct is a data structure format in Solidity where variables of diverse data types can be bundled into one variable or a custom-made type. Once the data types are grouped into a struct data type, the struct name represents the subsets of variables present in it. • Defining a Struct • To define a Struct, you must have to use the struct keyword. The struct keyword defines a user-defined data type, with more than one member. The format of the struct statement is given as follows: • Syntax • struct struct_name { type1 type_name_1; type2 type_name_2; type3 type_name_3; }
- 22. Function and function modifiers • In Solidity, functions are the basic units of code that perform specific tasks or operations. They can be defined within contracts to encapsulate functionality. • Function modifiers are special code snippets in Solidity that can be used to add behavior to functions. They allow you to define conditions that must be met before a function can be executed, such as checking permissions or validating inputs.
- 23. Smart Contracts Development • Smart contracts development in Solidity involves writing code in the Solidity programming language to create self-executing contracts that automatically enforce the terms of an agreement when certain conditions are met. These contracts are deployed on blockchain platforms like Ethereum and enable decentralized applications (DApps) to run autonomously without the need for intermediaries.
- 24. Simple Smart Contract • This simple smart contract allows for depositing and withdrawing funds. It stores an owner's address and a value, allowing the owner to deposit and withdraw funds. You can deploy this contract on the Ethereum blockchain and interact with it using functions like deposit and withdraw.
- 25. Events and Error Handling • Events in programming refer to actions or occurrences detected by the program that may require a response. Error handling, on the other hand, deals with managing unexpected or erroneous situations that occur during program execution, ensuring the program can gracefully recover or terminate without causing further issues.
- 26. Introduction to Remix IDE • Remix IDE is a web-based integrated development environment (IDE) for Ethereum smart contract development. It offers features like code editing, debugging, testing, and deployment, all within a browser interface. With Remix, developers can efficiently build, test, and deploy smart contracts on the Ethereum blockchain.
- 27. Experiment 1: Write a Solidity contract that defines variables of different data types (uint, string, address, etc.) and performs basic operations on them, such as arithmetic operations and concatenation • This contract defines three variables: myUint, myString, and myAddress. The myUint variable is of type uint, which is a 256-bit unsigned integer. The myString variable is of type string, which is a variable-length string. The myAddress variable is of type address, which is a 20-byte value that represents an Ethereum address. • The contract also defines two functions: addUint() and concatenateString(). The addUint() fu nction takes two uint values as input and returns their sum. The concatenateString() function takes two string values as input and returns their concatenation. • Finally, the contract defines two functions that call the basic operations functions: addMyUints() and concatenateMyStrings(). The add MyUints() function simply calls the addUint() function with the myUint variable and the value 1 as input. The concatenateMyStrings() function simply calls the concatenateString() function with the myString variable and the value "!" as input. • To use this contract, you would first need to compile it and deploy it to the Ethereum blockchain. Once the contract is deployed, you can call
- 28. Experiment 2: Develop a simple smart contract using Remix IDE that implements a basic voting system. Deploy the contract on a local Ethereum test network using. Remix and interact with it through the Remix interface. • Steps to deploy and interact with the contract using Remix IDE: • Open Remix IDE (https://remix.ethereum.org/). • Create a new file named VotingSystem.sol. • Paste the above code into the editor. • Compile the contract by selecting the Solidity compiler version and clicking on the "Compile" tab. • Deploy the contract by selecting the "Deploy & Run Transactions" tab. • Under the "Environment" dropdown, select "Injected Web3" to connect to your local Ethereum test network (e.g., Ganache). • Click on the "Deploy" button to deploy the contract. • Once the contract is deployed, you can interact with it through the Remix interface. • To vote, call the vote() function with the desired option as the parameter. • To close the voting, call the closeVoting() function (only the contract owner can do this)