Understanding Blockchain: Transactions, Security, and Applications

Blockchain technology enables secure, transparent transactions without reliance on banks or third-party applications.

### Understanding Blockchain: The Future of Transactions and Real-World Applications
* 💡 Blockchain technology offers a **seamless way to complete transactions** without the hassles of online wallets, banks, or third-party applications.
* 🍽 In a scenario where friends split a dinner bill, Jack's experience with failed bank transactions highlights the potential issues with traditional banking, such as **technical glitches and transfer limits**.
* 💰 The emergence of cryptocurrencies, which operate on blockchain technology, addresses these banking challenges by providing a **secure and decentralized method of transaction**.
* 🔗 Each transaction in blockchain creates a **permanent record** in a block, forming a **public distributed ledger** that is shared among users, ensuring **transparency and security**.
* 🔒 The encryption of transaction data using **unique public and private keys** prevents unauthorized access and alterations, making blockchain **resistant to hacking**.
* ⛏ Miners validate transactions through a process called **proof of work**, solving **complex mathematical problems** to add blocks to the blockchain, with rewards such as **12.5 bitcoins** for their efforts.
* 🏬 Companies like Walmart utilize blockchain to track product quality throughout the supply chain, allowing them to **quickly identify and address issues** that lead to **returns and refunds**.
* 📝 As blockchain continues to evolve, its applications are expanding, prompting discussions about its **potential uses in various industries beyond finance**.

ever wonder if there's an easier way to complete transactions without having to deal with online wallets, banks, and third-party applications? Well, it's possible thanks to blockchain. Here's everything you need to know about blockchain. Imagine four friends: Jack, Ted, Sam, and Phil meet up for dinner. After they're done, Jack pays the bill, and all of them decide to split the expense amongst each other. Now, on the next day when Phil sends his share to Jack via online money transfer, the transaction goes through without a hitch. Then Ted and Sam send their respective shares to Jack, but their transactions don't go through. The failed transaction cites some issues at the bank. That's when Jack comes to know about the many ways a bank transaction could fail. It could be due to technical issues at the bank, one of their accounts being hacked, daily transfer limits being exceeded, and sometimes additional charges like transfer charges associated with transferring money. To solve these problems, the concept of cryptocurrency came into existence. Cryptocurrencies are a form of digital or virtual currency that run on a technology known as

blockchain. Thanks to blockchain, cryptocurrencies are immune to counterfeiting, don't require a central authority, and are protected by strong and complex encryption algorithms. In a market of more than thousands of cryptocurrencies like Litecoin, Ethereum, Zcash, and so on, one reigns supreme: Bitcoin. Now let's go back to our previous example and have Phil, Ted, and Sam send Jack two bitcoins each as their contribution to the previous night's dinner. Let's assume Phil, Ted, and Sam have three bitcoins in reserve while Jack has five. First, Phil sends two bitcoins to Jack. A record is created in the form of a block. The transaction details between them are permanently inscribed in this block. This record also holds the number of bitcoins each of the friends owns. So, after Phil's transaction, Jack has seven bitcoins while Phil has one. Following this, Sam and Ted send two bitcoins to Jack. A new block is created for each of these transactions. These blocks hold the transaction details as well as how many bitcoins Sam, Ted, and Jack have in reserve. These blocks are

linked to each other, as each of them takes reference from the previous one for the number of bitcoins each brand owns. This chain of records or blocks is called a ledger, and this ledger is shared among all the friends, which acts as a public distributed ledger. This forms the basis of blockchain. So, what happens when Phil has only one bitcoin left and he tries to send two more bitcoins to Jack? The transaction will not go through. This is because all his friends have copies of the ledger, and it's clear that Phil has only one bitcoin left. His friends will flag this transaction as invalid. A hacker will not be able to alter the data in the blockchain because each user has a copy of the ledger. The data within the blocks are encrypted by complex algorithms. All of this is made possible with the help of blockchain technology. Blockchain can be described as a collection of records linked with each other, strongly resistant to alteration, and protected using cryptography. Now, let's have a closer look at the bitcoin transaction between Jack and Phil and find out how.

It works. Every user in the bitcoin network has two keys: a public key and a private key. The public key is an address that everyone in the network knows of, like an email address of a user. The private key is a unique address that only the user has knowledge of, something like a password. First, Phil passes the number of bitcoins he wants to send to Jack, along with his and Jack's unique wallet address, through a hashing algorithm. All of this is part of the transaction details. These details are encrypted using encryption algorithms and using Phil's unique private key. This is done to digitally sign the transaction and to indicate that the transactions came from Phil. This output is now transmitted across the world using Jack's public key. With this, the message or transaction can be decrypted only by Jack's private key, which only Jack has knowledge of. Different cryptocurrencies use different hashing algorithms. While Bitcoin uses the SHA-256 algorithm, Ethereum, which is also a famous cryptocurrency, uses one known as Ethash. This transaction and several other similar ones are taking place all around the world. These transactions are

validated and then added block by block. The people who validate these blocks are called miners. For a block to be validated and added to a blockchain, miners need to solve a complex mathematical problem. The miner who solves this first adds the block to the blockchain and is rewarded with 12.5 bitcoins. The process of solving the complex mathematical problem is called proof of work, and the process of adding a block to the blockchain is called mining. With this, Phil and Jack's wallets are updated, just like every person in the network who has completed a transaction. Now that you know about blockchain and its important concepts, time for a small quiz. What is the concept of blockchain that ensures data cannot be altered by any of the users within the network? a) public distributed ledger b) proof of work c) proof of stake d) hash encryption. Let us know what you think is the right answer in the comments below. Three lucky winners will get Amazon gift vouchers. Details are mentioned in the description below. Let's have a look at how Walmart uses blockchain to provide its customers with

better service. Walmart was facing problems in delivering quality products to its customers. They were facing a high return rate and large amounts of refunds due to their products' bad quality. They were unable to determine the point of failure in the supply chain, which started from farm to storage to transportation to processing, all the way to the customer. Then Walmart adopted blockchain technology. With blockchain, the quality of the goods at each step was permanently inscribed within a block. For example, when a customer flags a product as damaged, it can be correctly identified where the product got damaged in the entire supply chain, thus helping Walmart to identify the problem areas and fixing them. And this is just one of several ways blockchain is used in real-life applications. Can you think of any others? Let us know in the comments down below. That's all for now. Thank you for watching and stay tuned for more.

Blockchain In 7 Minutes | What Is Blockchain | Blockchain Explained|How Blockchain Works|Simplilearn

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Understanding Blockchain and Cryptocurrency

Blockchain technology offers a solution to transaction failures common with banks and online wallets.

Cryptocurrencies, running on blockchain, are immune to counterfeiting and don't require a central authority.

Bitcoin is the most dominant cryptocurrency, with its transactions and ownership records permanently inscribed in blocks.

Bitcoin transactions are recorded in a public distributed ledger, or blockchain, which is shared among all users.

Each user has a public and private key, with the public key serving as the address for transactions and the private key providing unique access.

Transactions are encrypted and digitally signed using the sender's private key, and the output is transmitted using the recipient's public key, ensuring secure and verified transfers.

Miners validate and add blocks to the blockchain by solving complex mathematical problems.

The first miner to solve the problem is rewarded with 12.

This process, known as proof of work, updates the wallets of all users in the network who have completed a transaction.

Walmart's Use of Blockchain for Better Service

Walmart struggled with high return rates and refunds due to poor product quality.

The company adopted blockchain technology to permanently inscribe the quality of goods at each supply chain step.

This innovation allowed Walmart to accurately identify and fix problem areas when a customer flagged a damaged product.