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Week 1
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Week 1 - The basics of Bitcoins and
Blockchains by
Mr. Lewis
https://www.youtube.com/watch?v=-xEdF8utQNE&t=650s
(audiobook)
Cryptography:
from 2:38:27 to 3:10:08
Bitcoin: from 3:10:08 to 5:41:05
Etherum from 5:41:05 to 8:08:51
PPT on
Cryptography
Blockchain in general, Bitcoin, Bitcoin
Mining, POW PPT
Quiz1
· Also watch Blockchain
Full Course - 4 Hours |Simplilearn (from beginning to 1:20:10)
https://www.youtube.com/watch?v=SyVMma1IkXM&t=4849s
Blockchain in general, and Bitcoin
1.
What is Bitcoin?
- Definition: Bitcoin is a decentralized digital
currency, created in 2009 by an unknown person or group of people
using the pseudonym Satoshi Nakamoto. It operates without a central
authority or banks.
- How it works: Bitcoin transactions are recorded
on a public ledger called the blockchain, which is maintained by a
network of computers (nodes).
2.
The Technology Behind Bitcoin
- Blockchain: The concept of blockchain as a
distributed ledger that records all transactions across a network of
computers. Each block in the chain contains a list of transactions and
is linked to the previous block, forming a chain.
- Mining: The process of mining, where
participants (miners) use computational power to solve complex
mathematical problems that validate and secure transactions on the
Bitcoin network. In return, miners are rewarded with newly created
bitcoins.
3.
Why Bitcoin?
- Decentralization: Unlike traditional currencies,
Bitcoin is not controlled by any central government or institution.
This decentralization is a key feature that attracts many users.
- Limited Supply: There will only ever be 21 million
bitcoins, which creates scarcity and can drive demand.
- Transparency and
Security:
Bitcoin transactions are transparent and secure, thanks to the
blockchain. Transactions cannot be altered once they are recorded,
which provides a high level of security.
4.
How to Use Bitcoin
- Transactions: Bitcoin can be used to buy goods
and services, transferred between individuals, or held as an
investment.
- Wallets: The concept of Bitcoin wallets,
which are digital tools that allow users to send, receive, and store
their bitcoins. Wallets can be software-based (like apps) or
hardware-based (physical devices).
5.
The Impact of Bitcoin
- Financial
Innovation:
Bitcoin is considered the first successful cryptocurrency and has
paved the way for thousands of other digital currencies.
- Global Economy: The potential impact of Bitcoin on
the global financial system, including topics like financial
inclusion, remittances, and challenges to traditional banking systems.
- Challenges and
Criticisms:
Some challenges Bitcoin faces, such as regulatory issues, price
volatility, and environmental concerns related to mining.
6.
Future of Bitcoin
- Adoption: Growing acceptance of Bitcoin by
businesses, investors, and even some governments.
- Technological
Advancements:
Mention ongoing developments, such as the Lightning Network, which
aims to make Bitcoin transactions faster and cheaper.
1. What is Bitcoin Mining?
- Definition: Bitcoin mining is the process by
which new bitcoins are created and transactions are added to the
blockchain, the public ledger of all Bitcoin transactions.
- Analogy: Think of Bitcoin mining as a
competitive game. In this game, participants (called miners) are
trying to solve a really difficult puzzle. The first one to solve the
puzzle gets to add a new block of transactions to the blockchain and
is rewarded with new bitcoins.
2. The Role of Hashing
- What is Hashing? Hashing is like taking a piece of
information (like a list of transactions) and running it through a special
mathematical function that turns it into a unique string of numbers
and letters. This string is called a "hash."
- Analogy: Imagine hashing as a blender. You
put in different ingredients (transactions), blend them, and what
comes out is a smoothie (the hash). Even if you slightly change the
ingredients (like changing a single transaction), you’ll
get a completely different smoothie (hash).
3. Proof of Work (PoW)
- Definition: Proof of Work is the mechanism
that makes Bitcoin mining possible. It requires miners to solve a
complex mathematical problem before they can add a new block to the
blockchain. This problem is solved by finding a special kind of hash.
- How it Works:
- The puzzle miners are trying to
solve involves finding a hash that starts with a certain number of
zeros.
- Miners do this by trying different
inputs (numbers called "nonces") until they find one that,
when hashed, produces the required hash with the zeros.
- The process takes a lot of
computational power because miners have to try many different nonces
before they find the right one.
- Analogy: Think of PoW as a guessing game.
The game asks miners to guess a number, but the only way to know if
the guess is correct is to try it and see if it works. This means
miners have to make many, many guesses before they get it right.
4. Why is Mining Important?
- Security: The difficulty of solving the PoW
puzzle ensures that Bitcoin's blockchain is secure. Because it takes
so much effort to solve, it’s practically
impossible for someone to change or tamper with a block once it’s been added to the blockchain.
- Decentralization: Mining is decentralized, meaning
that anyone with the right equipment can participate, which helps keep
the Bitcoin network fair and secure.
5. Mining Rewards
- Block Reward: When a miner successfully solves
the PoW puzzle and adds a new block to the blockchain, they are
rewarded with a certain number of bitcoins. This is called the block
reward.
- Transaction Fees: In addition to the block reward,
miners also earn transaction fees from the transactions included in
the block they added to the blockchain.
6. Environmental Concerns
- Energy Use: Mining requires a lot of
computational power, which in turn requires a lot of electricity. This
has raised concerns about the environmental impact of Bitcoin mining.
- Efforts to
Improve:
The Bitcoin community is continually looking for ways to make mining
more energy-efficient, including exploring alternative consensus
mechanisms and renewable energy sources.
Summary
- Bitcoin mining is the process of
adding new transactions to the blockchain and earning new bitcoins as
a reward.
- Hashing is used to turn transaction
data into a unique code, and miners must find a specific type of hash
to solve the PoW puzzle.
- PoW is a guessing game that ensures
Bitcoin’s security by making it hard to alter
the blockchain.
PPT on Bitcoin Wallet ppt Quiz
Simplilearn
4 hour course (2:35:34 –
2:57:05) Crypto Wallet
Simulator
1. What is a Bitcoin Wallet?
- Definition: A Bitcoin wallet is a digital tool
that allows you to send, receive, and store your bitcoins. It’s like a bank account for your bitcoins, but
instead of holding physical money, it holds digital currency.
- Analogy: Imagine a Bitcoin wallet as a real
wallet you carry in your pocket. Just like you use your physical
wallet to store cash, a Bitcoin wallet stores your digital money
(bitcoins).
2. How Does a Bitcoin Wallet Work?
- Private Key and
Public Key:
- Private Key: This is a secret code that allows
you to access and control your bitcoins. It’s
like the password to your bank account. If someone has your private
key, they can spend your bitcoins, so it’s
essential to keep it safe.
- Public Key: This is like your bank account
number. It’s a code that people use to send
you bitcoins. You can share your public key with others, and they can
use it to send bitcoins to your wallet.
- Analogy: Think of your private key as the
key to a safety deposit box. Only you should have access to this key
because it gives you control over the money inside. The public key is
like the address of the bank where your safety deposit box is located,
which others can use to send money to your box.
3. Types of Bitcoin Wallets
- Software Wallets:
- These are apps or programs you can
install on your computer or smartphone. They allow you to easily
access and manage your bitcoins.
- Example: Mobile wallets like Coinbase or
desktop wallets like Electrum.
- Hardware Wallets:
- These are physical devices, like a
USB stick, that store your private keys offline. They are more secure
because they are not connected to the internet, making them less
vulnerable to hacking.
- Example: Ledger Nano S, Trezor.
- Paper Wallets:
- This is a piece of paper with your
public and private keys printed on it. It’s a
very secure way to store bitcoins, as long as you keep the paper
safe.
- Example: You generate a paper wallet using
a secure online service, then print it out and store it in a safe
place.
- Analogy: If a software wallet is like an
app on your phone, a hardware wallet is like a safe that you keep at
home, and a paper wallet is like writing down your bank details on a
piece of paper and keeping it in a safe place.
4. Why Use a Bitcoin Wallet?
- Security: A Bitcoin wallet helps keep your
bitcoins safe. By securely storing your private key, you control who
can access your funds.
- Convenience: Bitcoin wallets make it easy to
send and receive bitcoins. You can quickly make transactions by
scanning a QR code or entering an address.
- Ownership: When you have a Bitcoin wallet,
you have full control over your bitcoins. No one else can access your
funds unless they have your private key.
5. How to Use a Bitcoin Wallet
- Receiving
Bitcoins:
- To receive bitcoins, you give
someone your public key (or wallet address). They send the bitcoins
to that address, and it shows up in your wallet.
- Example: You can send your friend a QR
code that represents your wallet address, and they can scan it to
send you bitcoins.
- Sending Bitcoins:
- To send bitcoins, you enter the
recipient’s wallet address and the amount you
want to send. The wallet uses your private key to authorize the
transaction.
- Example: If you want to pay for something
online with Bitcoin, you would enter the seller's wallet address and
send the payment through your wallet.
6. Security Tips
- Backup: Always back up your wallet. If you
lose your private key, you lose your bitcoins forever.
- Secure Storage: Keep your private key safe. Use
hardware wallets or paper wallets for long-term storage, especially if
you have a significant amount of bitcoins.
- Beware of Scams: Never share your private key with
anyone, and be cautious of phishing attempts that try to steal your
private key.
Summary
- A Bitcoin wallet is a digital tool
that stores your private and public keys, allowing you to send,
receive, and store bitcoins.
- There are different types of
wallets (software, hardware, paper), each offering varying levels of
security and convenience.
- Security is crucial; keep your
private key safe and always back up your wallet.
(Disclaimer:
Some of the slides posted on this website are screenshots from the Simplilearn 4 Hour
Blockchain video at https://www.youtube.com/watch?v=SyVMma1IkXM&t=4849s)
Quiz to
assess knowledge on the first day of class
Bitaddress.org
Bitaddress.org is
an open-source, web-based tool for generating Bitcoin addresses and their
corresponding private keys. It's a simple and secure way to create Bitcoin wallets offline,
without needing to rely on a centralized service.
How
to Use Bitaddress.org:
1.
Access the Site:
Go to bitaddress.org.
To enhance security, you can download the site’s
HTML file and run it offline.
2.
Generate a Bitcoin
Address:
·
Move your mouse around or type random
characters in the provided box to add randomness. This process helps in
generating a unique Bitcoin address.
·
Once enough randomness is collected, a
Bitcoin address and its corresponding private key will be displayed.
3.
Save Your Keys:
·
You can print the generated address and
private key on paper (often called a paper wallet).
·
Store the printed document securely, as
anyone with access to your private key can access your Bitcoin.
4.
Use the Address:
·
The Bitcoin address can be shared with
others to receive Bitcoin.
·
The private key is used to send or
transfer Bitcoin from that address.
Important:
Always ensure you are using Bitaddress.org securely, preferably offline,
and keep your private key safe to prevent unauthorized access to your
funds.
https://etherscan.io/
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Etherscan.com
is a popular blockchain explorer specifically designed for the Ethereum
network. It allows users to explore and search the Ethereum blockchain for
transactions, addresses, tokens, prices, and other activities.
Key
Features of Etherscan:
1.
Transaction Tracking:
·
You can search for any Ethereum
transaction by entering its transaction hash (TXID) into the search bar.
This will provide details such as the amount transferred, gas fees, block
confirmation, and the status of the transaction (e.g., pending, successful,
failed).
2.
Wallet and Address
Lookup:
·
Etherscan allows you to view the balance
and transaction history of any Ethereum address. Just enter the wallet
address in the search bar to see the current Ether balance, list of ERC-20 tokens
held, and transaction history.
3.
Smart Contract
Interaction:
·
You can view, verify, and interact with
smart contracts directly on Etherscan. It shows the contract's source code,
ABI (Application Binary Interface), and allows you to execute functions if
the contract is verified.
4.
Token Information:
·
Etherscan provides information on all
ERC-20 tokens, including their contract address, holders, transactions, and
price data.
5.
Gas Tracker:
·
The site features a gas tracker that
shows real-time information on Ethereum gas prices, helping users choose
optimal times for transactions to minimize fees.
How
to Use Etherscan:
1.
Search Transactions or
Addresses:
·
Enter a transaction hash, wallet
address, or smart contract address into the search bar to retrieve detailed
information.
2.
Explore Contracts:
·
If you're dealing with a smart contract,
you can search for it on Etherscan to review its code, check its status, or
interact with it directly.
3.
Check Gas Fees:
·
Use the gas tracker to monitor current
gas prices and plan your transactions accordingly.
4.
Token Lookup:
·
Search for any ERC-20 token to view its
distribution, market data, and associated transactions.
Etherscan
is an essential tool for anyone working with Ethereum, offering
transparency and a wealth of information about the blockchain.
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Useful
Websites:
1. Ethereum.org
- Ethereum
Official Site
- Great resource for learning about Ethereum, the leading
platform for decentralized applications (dApps) and smart contracts.
2.
Solidity
Documentation // https://docs.soliditylang.org/en/v0.8.26/
- Solidity Official Documentation
- Comprehensive guide for learning Solidity, the programming
language for writing smart contracts on Ethereum.
3.
Remix IDE https://remix.ethereum.org/#lang=en&optimize=false&runs=200&evmVersion=null&version=soljson-v0.8.26+commit.8a97fa7a.js
- Remix IDE
- Online integrated development environment for Solidity
development, providing tools for writing, testing, and debugging smart
contracts.
4. OpenZeppelin
- OpenZeppelin
- Framework for building secure smart contracts with libraries,
tools, and educational resources.
5. CryptoZombies
- CryptoZombies
- Interactive tutorial that teaches Solidity by guiding students
through building their own blockchain-based game.
6. Truffle
Suite
- Truffle
Suite
- Development environment, testing framework, and asset pipeline
for Ethereum, aimed at making development easier.
7. Hardhat
- Hardhat
- Ethereum development environment for professionals, with
features for compiling, deploying, testing, and debugging Solidity
code.
8. Dapp
University
- Dapp
University
- Offers tutorials and courses on blockchain development,
including Solidity and Ethereum.
9. Solidity
by Example
10. EthHub https://docs.ethhub.io/
- EthHub
- Comprehensive resources on Ethereum, including guides on smart
contracts, Solidity, and blockchain development.
11. Chainlink
Documentation https://docs.chain.link
- Chainlink Documentation
- Resources for integrating Chainlink decentralized oracles with
smart contracts to enable off-chain data access.
12. Ethers.js https://docs.ethers.org/v6/
- Ethers.js
- JavaScript library for interacting with the Ethereum
blockchain, useful for front-end developers integrating smart
contracts.
13. DeFi
Pulse
- DeFi Pulse
- Track the latest stats and trends in decentralized finance
(DeFi) projects.
14. State
of the DApps
- State
of the DApps
- Directory and analytics for decentralized applications,
showcasing the latest dApps and their usage statistics.
15. Github
Websites for beginners learning about Ethereum and
blockchain:
1.
Ethereum Foundation
Blog https://blog.ethereum.org/
- Ethereum Foundation Blog
- Official blog with updates, news, and educational articles
about Ethereum.
2.
Consensys
Academy https://consensys.io/academy
- Consensys Academy
- Offers courses and resources on Ethereum development,
blockchain basics, and more.
3. Blockgeeks
- Blockgeeks
- Provides educational articles, guides, and courses on blockchain
technology and Ethereum.
4. Coursera
- Blockchain Specialization
5. CryptoCompare
- CryptoCompare
- Provides data, news, and educational resources on
cryptocurrencies and blockchain technology.
6. CoinDesk
- CoinDesk
- Leading news website that covers blockchain, Ethereum, and
cryptocurrency trends and developments.
7. DappRadar
- DappRadar
- A platform for exploring and tracking decentralized applications
(dApps) across multiple blockchains.
8. The
Ethereum Reddit Community
- Ethereum
Subreddit
- A community forum where beginners can ask questions, share
information, and learn more about Ethereum.
9. Binance
Academy https://academy.binance.com/\
- Binance Academy
- Provides educational resources on blockchain, cryptocurrency,
and decentralized finance (DeFi).
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Week 2
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Week 2 –
Ethereum
Part I – What is Ethereum?
A Comparison between Ethereum and Bitcoin
Quiz2
1. Introduction to Ethereum
- Definition: Ethereum is a decentralized,
open-source blockchain platform that enables developers to build and
deploy decentralized applications (dApps) and smart contracts. It was
proposed by Vitalik Buterin in 2013 and launched in 2015.
- Purpose: While Bitcoin was created as a
digital currency, Ethereum was designed to be a more versatile platform,
allowing for the creation of decentralized applications beyond just
currency.
2. Key Features of Ethereum
- Smart Contracts:
- Definition: Smart contracts are self-executing
contracts with the terms of the agreement directly written into code.
They automatically enforce and execute the contract when certain
conditions are met, without the need for intermediaries.
- Example: Imagine a vending machine as a
smart contract. You insert money, select a product, and the machine
automatically delivers it to you. There's no need for a cashier because
the contract (machine) handles everything.
- Ethereum Virtual
Machine (EVM):
- Definition: The EVM is a global decentralized
computer that runs the smart contracts on the Ethereum network. It
allows anyone to execute code in a decentralized manner, ensuring that
the same result is achieved everywhere.
- Decentralized
Applications (dApps):
- Definition: dApps are applications that run on
a blockchain network rather than a central server. They leverage
Ethereum’s smart contracts to function without
a central authority.
- Example: A decentralized social media
platform where users control their data, and no single entity can
censor or remove content.
3.
A Comparison between Bitcoin and Ethereum PPT Simplilearn 4
hour video (2:57:06 – 3:03:00)
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Feature
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Bitcoin
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Ethereum
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Primary Purpose
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Digital currency (peer-to-peer
transactions)
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Platform for decentralized
applications and smart contracts
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Launch Year
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2009
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2015
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Founder
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Satoshi Nakamoto
(pseudonymous)
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Vitalik Buterin
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Native Cryptocurrency
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Bitcoin (BTC)
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Ether (ETH)
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Supply
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Maximum supply of 21 million
BTC
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No fixed supply; continuous
issuance of ETH
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Blockchain Structure
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Simple, secure, focused on
transactions
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Complex, programmable,
supports smart contracts and dApps
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Consensus Mechanism
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Proof of Work (PoW)
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Transitioning from PoW to
Proof of Stake (PoS) with Ethereum 2.0
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Transaction Speed
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~10 minutes per block
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~15 seconds per block
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Scalability
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Handles ~7 transactions per
second (TPS)
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More scalable; ongoing
upgrades like Ethereum 2.0 aim to further improve scalability
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Smart Contracts
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Not supported
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Fully supported; core
feature of the platform
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Decentralized Applications
(dApps)
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Not supported
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Fully supported; numerous
dApps are built on Ethereum
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Use Case
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Digital money, store of value
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Platform for building
decentralized applications and smart contracts
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Energy Efficiency
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Energy-intensive due to PoW
mining
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Moving towards energy
efficiency with PoS in Ethereum 2.0
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Nickname
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Often referred to as
"Digital Gold"
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Sometimes called
"Programmable Blockchain"
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Part II – Ethereum
Mining ppt
1. What is Ether Mining?
- Definition: Ether mining is the process of
validating transactions on the Ethereum blockchain and adding them to
the public ledger. Miners use computational power to solve complex
mathematical puzzles, and in return, they are rewarded with newly
created Ether.
2. How Ether Mining Works
- Proof of Work
(PoW): Ethereum currently uses the Proof of
Work (PoW) consensus mechanism, similar to Bitcoin. Miners compete to
solve cryptographic puzzles, and the first one to solve it gets to add a
block of transactions to the blockchain and earns Ether as a reward.
- Hashing: To solve the puzzle, miners use a
hashing function (specifically, Ethash for Ethereum). They repeatedly
process the block data through the hashing function with different
"nonces" (random numbers) until they find a hash that meets
the network’s difficulty target.
3. Equipment Needed
- Mining Hardware: To mine Ether, you need a powerful
computer with a high-performance GPU (Graphics Processing Unit). GPUs
are preferred for mining because they are more efficient than CPUs for
the type of calculations involved in mining.
- Mining Software: You’ll need
mining software that connects your hardware to the Ethereum network.
Popular mining software includes Ethminer, PhoenixMiner, and Claymore.
- Ethereum Wallet: You’ll need
an Ethereum wallet to store the Ether you mine. This can be a software
wallet (like MetaMask) or a hardware wallet (like Ledger or Trezor) for
added security.
4. Mining Solo vs. Joining a Pool
- Solo Mining: In solo mining, you mine
independently. While the rewards can be significant if you solve a
block, it’s highly competitive and may take a
long time before you find a block.
- Mining Pool: Most miners join a mining pool,
where multiple miners work together to solve blocks. The rewards are
shared among all participants based on the amount of computational power
they contribute. This provides more consistent, though smaller,
earnings.
5. Steps to Start Mining Ether
- Set Up Hardware: Install and configure your mining
hardware, ensuring you have a powerful GPU.
- Install Mining
Software: Download and install your chosen
mining software.
- Join a Mining Pool: If you prefer, join a mining pool to
increase your chances of earning rewards regularly.
- Start Mining: Begin mining by running the mining
software, which will connect your hardware to the Ethereum network and
start solving cryptographic puzzles.
- Monitor and
Optimize: Regularly monitor your mining
performance and optimize your setup to ensure efficient mining.
6. Transition to Proof of Stake (PoS)
- Ethereum 2.0: Ethereum is transitioning from Proof
of Work (PoW) to Proof of Stake (PoS) with Ethereum 2.0. In PoS,
validators are chosen to create new blocks based on the amount of Ether
they hold and "stake." This transition will eventually make
mining obsolete as the network moves towards staking.
Part III – Smart
Contract PPT
Simplilearn
4 hour video (from 1:27:14 to
2:13:44 ) Quiz
1. Definition
- Smart Contract: A smart contract is a self-executing
contract with the terms of the agreement directly written into lines of code.
It automatically enforces and executes the contract when certain
conditions are met, without the need for intermediaries like lawyers or
banks.
2. How Smart Contracts Work
- Code and
Conditions: The smart contract is
programmed to perform specific actions when certain predefined
conditions are met. For example, a smart contract could be set up to
transfer ownership of a digital asset automatically when payment is
received.
- Decentralization: Smart contracts run on a
decentralized blockchain network like Ethereum, meaning no single entity
controls them. Once deployed, they are immutable (cannot be changed) and
transparent, with the code visible to all participants.
3. Example of a Smart Contract
- Real Estate
Transaction: Imagine buying a house
through a smart contract. The contract could be programmed to
automatically transfer ownership of the property to the buyer when the
agreed payment is received. This eliminates the need for a middleman,
like a lawyer, to verify and process the transaction.
Software Needed for Smart Contracts
1. Development Environment
- Solidity: Solidity is the most commonly used
programming language for writing smart contracts on the Ethereum
blockchain. It’s similar to JavaScript in syntax
and is specifically designed for developing smart contracts.
- Remix IDE: Remix is an online Integrated
Development Environment (IDE) that allows developers to write, compile,
and deploy smart contracts in Solidity. It’s
beginner-friendly and widely used for Ethereum smart contract
development.
2. Blockchain Network
- Ethereum: Ethereum is the most popular
blockchain platform for deploying smart contracts. It provides a
decentralized environment where smart contracts can be executed securely
and transparently.
- Testnets: Before deploying a smart contract on
the Ethereum mainnet (the live blockchain), developers typically use
testnets like Ropsten or Rinkeby to test their contracts. This allows
them to identify and fix any issues without risking real Ether.
3. Wallet and Blockchain Interface
- MetaMask: MetaMask is a browser extension
wallet that allows users to interact with Ethereum dApps and smart
contracts. It also provides a way to manage your Ether and deploy smart
contracts.
- Truffle Suite: Truffle is a development framework
for Ethereum that provides tools for compiling, deploying, and managing
smart contracts. It’s often used in larger, more
complex smart contract projects.
Why Do We Need Smart Contracts?
1. Automation
- Self-Executing: Smart contracts automate processes
that would normally require manual intervention. For example, a smart
contract can automatically release funds when a task is completed or a
condition is met, reducing the need for middlemen.
2. Trust and Transparency
- Immutable and
Transparent: Once deployed, smart
contracts cannot be altered, ensuring that the terms of the agreement
are always enforced as written. The contract’s
code is also visible to everyone on the blockchain, which increases
transparency and trust among participants.
3. Cost Efficiency
- Reduced Costs: By eliminating intermediaries (like
lawyers, notaries, or escrow services), smart contracts reduce
transaction costs. This is especially beneficial in industries like
finance, real estate, and supply chain management, where traditional
processes can be slow and expensive.
4. Security
- Blockchain
Security: Smart contracts benefit from the
security of the underlying blockchain. Since they are decentralized and
cryptographically secure, they are highly resistant to fraud, tampering,
and censorship.
5. Global Reach
- Borderless: Smart contracts can be used globally
without the need for intermediaries or cross-border legal
considerations, making them ideal for international transactions and
agreements.
Summary
- Smart contracts are self-executing contracts
written in code that automatically enforce and execute agreements
without intermediaries.
- They require specific software tools,
including Solidity for programming, Remix for development, and Ethereum
as the blockchain platform.
- Smart contracts offer automation,
transparency, cost efficiency, security, and global reach, making them
valuable in many industries.
Part IV – Solidity
Coding PPT Simplilearn 6
hour video (from 1:26:00 – 2:41:55
)
1. Introduction to Solidity
- Definition: Solidity is a high-level programming
language designed specifically for writing smart contracts on the
Ethereum blockchain. It’s statically typed and
contract-oriented, meaning it allows developers to define the data
structure and functions that will govern the behavior of the smart
contract.
- Similarities to
JavaScript: Solidity syntax is
similar to JavaScript, making it easier to learn for those who are
already familiar with web development.
2. Purpose of Solidity
- Smart Contract
Development: Solidity is used to
create smart contracts that can handle various functions, such as
transferring tokens, enforcing agreements, creating decentralized
applications (dApps), and more.
- Blockchain
Interaction: Contracts written in
Solidity can interact with the Ethereum blockchain, allowing developers
to create decentralized and secure applications.
How to Compile and Deploy a Solidity Contract
1. Writing a Smart Contract
- Using Solidity: Start by writing the smart contract
in Solidity. You can use a basic text editor, but it’s
better to use a specialized Integrated Development Environment (IDE)
like Remix.
- Example Contract:
pragma solidity ^0.8.0;
contract SimpleStorage {
uint256 storedData;
function set(uint256 x) public {
storedData = x;
}
function get() public view returns (uint256) {
return storedData;
}
}
- Explanation: In this simple contract, there is a variable
storedData that can be set and retrieved
through the set and get functions.
2. Compiling the Smart Contract
- Open Remix at remix.ethereum.org.
- Create a new file and paste your
Solidity code into the editor.
- Select the compiler version (e.g.,
0.8.0) that matches the pragma statement in your code.
- Click on the "Compile"
button. If there are no errors, your contract will be compiled into
bytecode, which is what the Ethereum Virtual Machine (EVM) can execute.
- Output: The compiler will generate ABI
(Application Binary Interface) and bytecode, which are essential for
deploying and interacting with the contract.
3. Deploying the Smart Contract
- Using Remix with
MetaMask:
- Set Up MetaMask: Install the MetaMask browser extension
and set up a wallet. Make sure you have some Ether in your wallet for
gas fees (you can use test Ether on a test network like Ropsten).
- Deploy: In Remix, switch to the
"Deploy & Run Transactions" tab. Select "Injected
Web3" as the environment to connect Remix with MetaMask.
- Deploy the
Contract:
Select your contract from the dropdown and click "Deploy."
MetaMask will prompt you to confirm the transaction, which includes
paying a gas fee.
- Confirm
Deployment:
Once confirmed, the contract will be deployed to the Ethereum network
(or testnet), and you’ll receive a contract
address where it resides on the blockchain.
Procedure Summary
- Write your smart contract in Solidity
using an IDE like Remix.
- Compile the contract using the built-in compiler
in Remix, generating ABI and bytecode.
- Deploy the contract to the Ethereum network
via Remix and MetaMask.
- Interact with the deployed contract using the
contract’s functions through Remix or any other
Ethereum interface.
Main Troubleshooting Issues
1. Compilation Errors
- Syntax Errors: Most compilation errors come from
incorrect syntax. Always ensure that your Solidity code adheres to
proper syntax rules. Common issues include missing semicolons,
mismatched brackets, or incorrect function declarations.
- Version Mismatch: Ensure that the Solidity version in
your pragma statement (e.g.,
pragma
solidity ^0.8.0;) matches the version
selected in the Remix compiler. If there’s a
mismatch, the contract might not compile or behave as expected.
2. Deployment Issues
- Gas Limit Errors: Deployment can fail if the gas limit
is too low. The gas limit is the maximum amount of gas you’re willing to spend on the transaction. If it’s set too low, the contract won’t
deploy. Adjust the gas limit in MetaMask or the deployment settings in
Remix.
- Network Issues: Make sure you are connected to the
correct Ethereum network (mainnet, Ropsten, etc.) via MetaMask.
Deployment can fail if you’re on the wrong
network or if there’s a network outage.
3. Interaction Issues
- Contract Not Found: If you try to interact with a
contract and get an error saying it’s not found,
double-check the contract address. Ensure you’re
using the correct address on the correct network.
- Incorrect Data
Types: When interacting with the contract’s functions, ensure you’re
passing the correct data types. For example, if a function expects a
uint256, sending a string will cause an
error.
4. Gas Estimation Errors
- Incorrect Gas
Estimation: Sometimes, the gas
estimation might be too low for certain complex operations. In such
cases, manually increase the gas limit in MetaMask or your Ethereum
client.
- High Gas Fees: Gas fees can fluctuate based on
network congestion. If gas fees are too high, consider waiting for a
less congested time or deploying to a test network.
Conclusion
- Solidity coding allows developers to create and
deploy smart contracts on the Ethereum blockchain.
- Compiling and
deploying a contract involves writing the
code, compiling it to generate bytecode, and deploying it to the Ethereum
network using tools like Remix and MetaMask.
- Troubleshooting involves addressing common issues
like syntax errors, gas limits, and network connectivity problems.
Regular practice and careful attention to detail can help avoid many of
these issues.
Part V – DApp
(Decentralized Application) and DAO
PPT
Quiz
Simplilearn 4
hour video (from 3:02:31
to 3:09:15 )
1. Definition
- DApp: A decentralized application (DApp)
is an application that runs on a decentralized network, typically a
blockchain like Ethereum, rather than on a centralized server. Unlike
traditional apps, DApps are not controlled by a single entity and operate
on a peer-to-peer network.
2. Key Characteristics of DApps
- Decentralization: DApps are built on a blockchain,
which is maintained by a distributed network of computers (nodes) rather
than a single central authority. This ensures that no single entity has
control over the application.
- Open Source: Most DApps are open source, meaning
their code is available for anyone to inspect, use, and modify. This
transparency helps build trust among users.
- Smart Contracts: DApps use smart contracts, which are
self-executing contracts with the terms of the agreement directly
written into code. These contracts automate various functions of the
DApp without needing intermediaries.
- Tokenization: Many DApps have their own tokens,
which can be used within the application for various purposes, such as
payments, voting, or rewarding users. These tokens are often created
using Ethereum’s ERC-20 or ERC-721 standards.
3. How DApps Work
- Frontend: Like traditional apps, DApps have a
user interface (frontend) that users interact with. This can be a
website, mobile app, or any other user interface.
- Backend: Unlike traditional apps, the backend
of a DApp consists of smart contracts deployed on a blockchain. The
logic and data of the DApp are stored on the blockchain, making it
immutable and transparent.
- Interacting with
the Blockchain: Users interact with
the DApp through a web browser that connects to the blockchain. For
example, MetaMask is a popular browser extension that allows users to
interact with Ethereum-based DApps.
4. Examples of DApps
- Decentralized
Finance (DeFi): Platforms like Uniswap
(a decentralized exchange) and Aave (a lending platform) allow users to
trade and lend cryptocurrencies without relying on traditional financial
institutions.
- Gaming: Games like CryptoKitties allow users
to buy, breed, and trade virtual cats as non-fungible tokens (NFTs).
These assets are owned by the users and exist on the blockchain.
- Social Media: Platforms like Steemit offer
decentralized social networks where users can earn tokens for creating
and curating content, with no central authority controlling the
platform.
Why Do We Need DApps?
1. Trust and Security
- Transparency: Because DApps run on a blockchain,
all transactions and actions are transparent and verifiable by anyone.
This reduces the need to trust a central authority.
- Security: DApps are more resistant to hacking
and censorship because they are decentralized. Even if one part of the
network goes down or is compromised, the rest of the network continues
to function.
2. User Control and Ownership
- Data Ownership: In traditional apps, user data is
often controlled and monetized by the company that owns the app. In
DApps, users have greater control over their data, which is stored on
the blockchain and cannot be easily tampered with.
- Asset Ownership: In DApps that involve digital assets
(like tokens or NFTs), users truly own their assets. For example, if you
own an NFT in a DApp, it is stored on the blockchain and cannot be taken
away by anyone.
3. Innovation and Accessibility
- Global Access: DApps are accessible to anyone with
an internet connection, making them available globally without the restrictions
of traditional apps (like geographical restrictions or the need for a
bank account).
- Innovation: DApps enable new types of
applications that weren’t possible before, such
as decentralized finance (DeFi) platforms, decentralized exchanges, and blockchain-based
games.
Challenges and Considerations
1. Scalability
- Performance Issues: Since DApps run on a decentralized
network, they can face scalability issues, such as slower transaction
times and higher fees, especially during periods of high network
congestion.
- Ongoing
Development: Developers are
continuously working on solutions to improve the scalability and
performance of DApps, such as layer 2 scaling solutions and more
efficient consensus mechanisms.
2. User Experience
- Complexity: Using DApps can be more complex than
traditional apps, especially for users who are not familiar with
blockchain technology. For example, users need to manage private keys
and interact with smart contracts, which can be confusing for beginners.
- Improving Accessibility: Efforts are being made to improve
the user experience of DApps, making them more accessible to mainstream
users without compromising their decentralized nature.
Conclusion
- DApps are decentralized applications that
run on blockchain networks, offering transparency, security, and user
control.
- They leverage smart contracts to automate processes and
often use tokens for various functions within the app.
- DApps are increasingly popular in fields
like decentralized finance (DeFi), gaming, and social media, although
they face challenges like scalability and user experience.
(Disclaimer: Some of the slides posted on this website
are screenshots from the Simplilearn
4 Hour Blockchain video at https://www.youtube.com/watch?v=SyVMma1IkXM&t=4849s and Simplilearn 6 HourBlockchain Video at https://www.youtube.com/watch?v=9aXHQ98TMRY&t=6626s)
Part VI – Real World
Examples Quiz
1. Walmart – Supply Chain Management
·
Overview:
Walmart uses blockchain technology to improve the traceability and transparency
of its food supply chain. This implementation helps Walmart quickly identify
and address issues such as contamination or recalls, ensuring food safety and
reducing waste.
·
Blockchain Platform: IBM
Food Trust (built on Hyperledger Fabric) https://www.ibm.com/products/supply-chain-intelligence-suite/food-trust
·
Website:
- Walmart's
Blockchain Initiative:
IBM Food Trust for Walmart
- IBM Food Trust: IBM Food Trust
·
Additional Information: Walmart
was one of the first major retailers to adopt blockchain for supply chain
management, initially focusing on tracing pork and leafy greens to enhance
food safety.
2. Maersk – Shipping and Logistics
with TradeLens
·
Overview:
Maersk, in collaboration with IBM, developed TradeLens, a blockchain-based
platform designed to streamline global shipping processes. TradeLens enhances
transparency, reduces paperwork, and increases efficiency by providing
real-time access to shipping data and documents.
·
Blockchain Platform: TradeLens
(built on Hyperledger Fabric)
·
Website: TradeLens https://www.tradelens.com/
·
Additional Information:
TradeLens has partnered with numerous shipping companies, ports, and customs
authorities worldwide to create a more connected and efficient global trade
ecosystem.
3. De Beers – Diamond Provenance
Tracking with Tracr
·
Overview: De
Beers uses the Tracr platform to track diamonds from the mine to the retail
point. This ensures that each diamond is ethically sourced and conflict-free,
enhancing consumer trust and maintaining the integrity of their supply chain.
·
Blockchain Platform: Tracr
(developed by De Beers)
·
Website: De
Beers Tracr https://www.tracr.com/
·
Additional Information:
Tracr allows consumers to verify the origin and journey of their diamonds,
promoting transparency and ethical sourcing in the diamond industry.
4. Nestlé – Food Supply Chain Transparency
·
Overview:
Nestlé leverages blockchain technology to enhance the
transparency and traceability of its food products. By tracking ingredients
through the supply chain, Nestlé ensures quality,
safety, and ethical sourcing.
·
Blockchain Platform: IBM
Food Trust (built on Hyperledger Fabric)
·
Website:
Nestlé and IBM Food Trust https://www.ibm.com/blogs/think/2019/04/tracing-your-mashed-potatoes-on-ibm-blockchain/
·
Additional Information:
Nestlé's participation in IBM Food Trust helps the
company monitor the supply chain in real-time, ensuring that products meet
safety standards and are sourced responsibly.
5. FedEx – Package Tracking and
Logistics
·
Overview:
FedEx explores blockchain technology to improve its package tracking system,
aiming for more secure and transparent tracking information for shipments.
Blockchain enhances the reliability and efficiency of tracking packages
through the supply chain.
·
Blockchain Platform: Potential
Platforms: Hyperledger Fabric, Ethereum, or proprietary
solutions
·
Website:
FedEx Blockchain Initiatives https://www.fedex.com/en-us/about/policy/technology-innovation/blockchain.html
·
Additional Information:
FedEx has been involved in blockchain pilot projects to explore how
distributed ledger technology can optimize logistics and reduce fraud.
6. Provenance – Supply Chain Transparency
for Various Industries
·
Overview:
Provenance is a platform that helps businesses track the origins and journey
of their products using blockchain. This ensures transparency, ethical
sourcing, and allows consumers to verify product claims.
·
Blockchain Platform: Ethereum
and other blockchain technologies
·
Website: Provenance https://www.provenance.org/
·
Additional Information: Provenance
works with various industries, including fashion, food, and consumer goods,
to provide detailed product histories and build consumer trust through
transparency.
7. Microsoft – Azure Blockchain
Services
·
Overview:
Microsoft offers Azure Blockchain Services, enabling businesses to build,
deploy, and manage blockchain applications easily. Numerous companies use
Azure Blockchain to develop solutions across different industries such as
finance, supply chain, and healthcare.
·
Blockchain Platform: Azure
Blockchain (supports multiple blockchain frameworks including
Ethereum, Hyperledger Fabric)
·
Website:
Microsoft Azure Blockchain https://azure.microsoft.com/en-us/blog/digitizing-trust-azure-blockchain-service-simplifies-blockchain-development/
·
Additional Information:
Azure Blockchain provides tools and templates to help enterprises integrate
blockchain into their existing systems, facilitating faster and more secure
transactions.
8. JPMorgan Chase – Financial Services
with Quorum
·
Overview:
JPMorgan Chase developed Quorum, an enterprise-focused version of Ethereum,
to facilitate secure and efficient financial transactions. Quorum is used for
various applications, including payment processing, interbank transfers, and
blockchain-based financial instruments.
·
Blockchain Platform: Quorum
(a fork of Ethereum developed by JPMorgan Chase) https://phemex.com/academy/what-is-quorum-jp-morgan
·
Website:
Quorum by ConsenSys https://consensys.io/blog/what-is-consensys-quorum
·
Additional Information: Quorum
enhances Ethereum's capabilities by adding privacy features and improving
performance, making it suitable for enterprise use cases in the financial
sector.
9. IBM – Various Enterprise Blockchain
Solutions
·
Overview:
IBM offers a range of blockchain solutions tailored for different industries,
including supply chain, finance, healthcare, and more. IBM Blockchain, built
on Hyperledger Fabric, provides the infrastructure for businesses to create
secure and scalable blockchain applications.
·
Blockchain Platform: IBM
Blockchain (built on Hyperledger Fabric)
·
Website:
IBM Blockchain https://www.ibm.com/blockchain
·
Additional Information: IBM
collaborates with numerous enterprises to implement blockchain solutions that
enhance transparency, security, and efficiency in their operations.
10. Amazon Web Services (AWS) –
Managed Blockchain Services
·
Overview:
Amazon Web Services offers Amazon Managed Blockchain, a fully managed service
that makes it easy to create and manage scalable blockchain networks using
popular frameworks like Hyperledger Fabric and Ethereum.
·
Blockchain Platform: Amazon
Managed Blockchain (supports Hyperledger Fabric and Ethereum)
·
Website: Amazon
Managed Blockchain Distributed Ledger Software
& Technology - Amazon Managed Blockchain - AWS
·
Additional Information:
AWS Managed Blockchain allows businesses to quickly set up and manage
blockchain networks without the overhead of maintaining the underlying
infrastructure, supporting various use cases from supply chain to digital
identity.
11. Coca-Cola – Supply Chain and
Product Authentication
·
Overview:
Coca-Cola utilizes blockchain technology to enhance its supply chain
management and product authentication processes. Blockchain helps Coca-Cola
track ingredients, ensure quality, and authenticate products to prevent
counterfeiting.
·
Blockchain Platform: IBM
Food Trust (built on Hyperledger Fabric)
·
Website:
Coca-Cola and IBM Food Trust https://shping.com/shping-and-ibm-food-trust-pioneering-a-new-era-of-product-transparency-for-consumers/
·
Additional Information: By
integrating blockchain into its supply chain, Coca-Cola ensures better
transparency and efficiency, from sourcing raw materials to delivering
finished products.
12. Pfizer – Pharmaceutical Supply
Chain Management
·
Overview:
Pfizer uses blockchain to improve the traceability and security of its
pharmaceutical supply chain. Blockchain helps Pfizer ensure the authenticity
of medicines, prevent counterfeiting, and comply with regulatory
requirements.
·
Blockchain Platform: Provenance,
IBM Blockchain, or other enterprise blockchains
·
Website:
Pfizer and Blockchain Initiatives https://news.crunchbase.com/health-wellness-biotech/pharmaceuticals-blockchain-crypto-web3-pfizer-pfe/
·
Additional Information: Blockchain
technology enables Pfizer to maintain a secure and transparent record of its
supply chain, enhancing trust and safety in its pharmaceutical products.
13. Starbucks – Coffee Supply Chain
Tracking
·
Overview: Starbucks
has explored using blockchain to track the provenance of its coffee beans,
ensuring quality and ethical sourcing. Blockchain helps verify the journey of
the coffee from farm to cup, enhancing transparency and consumer trust.
·
Blockchain Platform: IBM
Food Trust (similar to Walmart and Nestlé)
·
Website:
Starbucks and Blockchain https://stories.starbucks.com/press/2022/starbucks-brewing-revolutionary-web3-experience-for-its-starbucks-rewards-members/
·
Additional Information: By
leveraging blockchain, Starbucks can provide customers with detailed
information about the origin and quality of their coffee, supporting sustainable
and ethical sourcing practices.
14. BP – Energy Supply Chain
Management
·
Overview: BP
utilizes blockchain technology to manage and optimize its energy supply
chain. Blockchain helps BP track the movement of energy resources, ensure
compliance with regulations, and improve the efficiency of transactions.
·
Blockchain Platform: IBM
Blockchain or other enterprise solutions
·
Website: BP
and Blockchain https://www.hartenergy.com/exclusives/bp-tries-out-blockchain-energy-trading-30388
·
Additional Information:
BP's adoption of blockchain in the energy sector demonstrates how blockchain
can enhance transparency, reduce costs, and improve operational efficiency in
complex supply chains.
15. Anheuser-Busch InBev – Beverage
Supply Chain Transparency
·
Overview:
Anheuser-Busch InBev uses blockchain to enhance the transparency and
efficiency of its beverage supply chain. Blockchain enables the company to track
ingredients, monitor production processes, and ensure the authenticity of its
products.
·
Blockchain Platform: IBM
Food Trust (built on Hyperledger Fabric)
·
Website: AB
InBev and IBM Food Trust https://www.foodnavigator.com/Article/2019/08/06/Anheuser-Busch-InBev-joins-new-IBM-blockchain
·
Additional Information: By
integrating blockchain into its supply chain, Anheuser-Busch InBev ensures
better quality control, traceability, and consumer trust in its beverage
products.
|
Company
|
Application
|
Token Use
|
|
Walmart, Nestlé,
Coca-Cola, BP
|
Supply Chain Management (IBM Food Trust)
|
No use of Ether or specific tokens; focus on transparency and
traceability.
|
|
Maersk
|
TradeLens (Shipping and Logistics)
|
No use of Ether or specific tokens; focus on logistics
transparency.
|
|
De Beers
|
Tracr (Diamond Provenance Tracking)
|
No use of Ether or specific tokens; ensures ethical sourcing.
|
|
FedEx
|
Package Tracking and Logistics
|
No use of Ether or specific tokens; focuses on tracking and
logistics.
|
|
Provenance
|
Supply Chain Transparency
|
May use tokens
depending on implementation, not necessarily Ether.
|
|
Microsoft Azure
Blockchain
|
Blockchain Services
|
Token use depends on
the specific application; Ether or custom tokens can be used.
|
|
JPMorgan Chase
|
Quorum (Enterprise Blockchain)
|
Can use Ether or
custom tokens depending on the application; often no tokens.
|
|
Uniswap
|
Decentralized Finance (DeFi)
|
Uses Ether (ETH) for
transactions and its own token (UNI) for governance.
|
|
Amazon Managed
Blockchain
|
Managed Blockchain Services
|
Token use depends on the specific application; not inherently
tied to Ether.
|
|
Pfizer
|
Pharmaceutical Supply Chain Management
|
No use of Ether or specific tokens; focuses on supply chain
security.
|
|
Starbucks
|
Coffee Supply Chain Tracking
|
No use of Ether or specific tokens; focuses on transparency.
|
|
|
