The document discusses blockchain technology and mining in blockchain networks. It explains that blockchain aims to replace centralized systems with decentralized networks to facilitate trustless transactions without third parties. Mining is the process by which transactions are verified and added to the blockchain in a decentralized manner. Miners use cryptographic hashing algorithms like SHA256 to find valid hashes that meet the network's difficulty criteria, allowing new blocks to be added to the immutable blockchain ledger. The nonce is a variable miners increment to get new hashes during the mining process.
Blockchain is a decentralized digital ledger that records transactions across many nodes in a network. Changes to transactions require consensus from other nodes. Blockchain technology is still developing and the costs and best applications are unknown. Blocks contain transaction data structured using techniques like hashing, Merkle trees, and asymmetric encryption to securely record transactions in the distributed ledger. The key components that enable blockchain are decentralized nodes, distributed ledger, transactions, blocks, hashing, public/private keys, and a consensus mechanism like proof-of-work mining.
Introduction to Blockchain Web3 SessionDSCIITPatna
Blockchain technology has been around since 2008 with the introduction of Bitcoin. It utilizes a decentralized digital ledger called a blockchain, which consists of records called blocks that are linked together in a growing list. Each block contains transaction data as well as a reference to the previous block. This allows transactions to be recorded in a verified and permanent way without the need for a central authority. There are various components that make up a blockchain network including nodes that host copies of the blockchain and wallets that store private and public keys for sending and receiving cryptocurrency. Various consensus mechanisms like proof-of-work and proof-of-stake are used to verify transactions and reach agreement across the decentralized network. Blockchain technology provides advantages like reduced costs and increased
Blockchain is a specific type of database where information is collected in blocks that are chained together, forming a chain of data known as the "blockchain." Each new block of information contains a reference to the previous block, linking them together in a way that makes tampering very difficult. Transactions are transmitted across a peer-to-peer network of computers, validated through solving equations, and collected into blocks that are added to the blockchain, forming a permanent record of all transactions.
This slide is about 'Blockchain Technology'. Blockchain is a method of recording information that makes it impossible or difficult for the system to be changed, hacked, or manipulated. A blockchain is a distributed ledger that duplicates and distributes transactions across the network of computers participating in the blockchain. Blockchain helps verify and trace multistep transactions needing verification and traceability. Cryptocurrencies are usually built using blockchain technology. Blockchain describes the way transactions are recorded into "blocks" and time stamped. It's a fairly complex, technical process, but the result is a digital ledger of cryptocurrency transactions that's hard for hackers to tamper with.
Blockchain Interview Questions And Answers | Blockchain Technology Interview ...Simplilearn
The document provides information to differentiate between Blockchain and Hyperledger:
- Blockchain is a decentralized technology that records immutable transaction records in blocks secured by cryptography. It can be public, private, or consortium. Hyperledger is a platform that allows building private blockchains where access is limited.
The document discusses how blockchain works through immutable ledgers, distributed peer-to-peer networks, and cryptographic hashing. It explains that blockchain uses the SHA-256 hashing algorithm to securely record transactions in distributed ledgers across a network, making the data incorruptible. It also describes how cryptographic hashing provides data integrity and commitment by linking blocks together, thus achieving immutability and preventing unauthorized changes to past transactions.
Blockchain is a distributed ledger that records transactions in blocks of data that are linked using cryptography. Key features include decentralization, transparency, immutability, and auditability. Blocks contain transaction data, a hash of the previous block, and a timestamp. Blockchains use peer-to-peer networks and consensus mechanisms like proof-of-work or proof-of-stake to validate new blocks. Smart contracts allow terms of an agreement to be automatically executed when conditions are met. The first blockchain concept dates to 1991, with Bitcoin's launch in 2009 popularizing the technology which has since grown to include various applications and cryptocurrencies.
Blockchain 101 provides an overview of blockchain technology. It discusses the two main types of blockchains - public and private. Key events that drove blockchain interest include the 2008 Bitcoin whitepaper and Ethereum's launch in 2015. The technical underpinnings of blockchain, including hashing, Merkle trees, and proof of work are explained. Examples are given of how blockchain is being used or explored in areas like land registry, identity, shipping, and healthcare. The document recommends resources for learning more about blockchain and names several smart experts to follow.
Blockchain is a decentralized digital ledger that records transactions across many nodes in a network. Changes to transactions require consensus from other nodes. Blockchain technology is still developing and the costs and best applications are unknown. Blocks contain transaction data structured using techniques like hashing, Merkle trees, and asymmetric encryption to securely record transactions in the distributed ledger. The key components that enable blockchain are decentralized nodes, distributed ledger, transactions, blocks, hashing, public/private keys, and a consensus mechanism like proof-of-work mining.
Introduction to Blockchain Web3 SessionDSCIITPatna
Blockchain technology has been around since 2008 with the introduction of Bitcoin. It utilizes a decentralized digital ledger called a blockchain, which consists of records called blocks that are linked together in a growing list. Each block contains transaction data as well as a reference to the previous block. This allows transactions to be recorded in a verified and permanent way without the need for a central authority. There are various components that make up a blockchain network including nodes that host copies of the blockchain and wallets that store private and public keys for sending and receiving cryptocurrency. Various consensus mechanisms like proof-of-work and proof-of-stake are used to verify transactions and reach agreement across the decentralized network. Blockchain technology provides advantages like reduced costs and increased
Blockchain is a specific type of database where information is collected in blocks that are chained together, forming a chain of data known as the "blockchain." Each new block of information contains a reference to the previous block, linking them together in a way that makes tampering very difficult. Transactions are transmitted across a peer-to-peer network of computers, validated through solving equations, and collected into blocks that are added to the blockchain, forming a permanent record of all transactions.
This slide is about 'Blockchain Technology'. Blockchain is a method of recording information that makes it impossible or difficult for the system to be changed, hacked, or manipulated. A blockchain is a distributed ledger that duplicates and distributes transactions across the network of computers participating in the blockchain. Blockchain helps verify and trace multistep transactions needing verification and traceability. Cryptocurrencies are usually built using blockchain technology. Blockchain describes the way transactions are recorded into "blocks" and time stamped. It's a fairly complex, technical process, but the result is a digital ledger of cryptocurrency transactions that's hard for hackers to tamper with.
Blockchain Interview Questions And Answers | Blockchain Technology Interview ...Simplilearn
The document provides information to differentiate between Blockchain and Hyperledger:
- Blockchain is a decentralized technology that records immutable transaction records in blocks secured by cryptography. It can be public, private, or consortium. Hyperledger is a platform that allows building private blockchains where access is limited.
The document discusses how blockchain works through immutable ledgers, distributed peer-to-peer networks, and cryptographic hashing. It explains that blockchain uses the SHA-256 hashing algorithm to securely record transactions in distributed ledgers across a network, making the data incorruptible. It also describes how cryptographic hashing provides data integrity and commitment by linking blocks together, thus achieving immutability and preventing unauthorized changes to past transactions.
Blockchain is a distributed ledger that records transactions in blocks of data that are linked using cryptography. Key features include decentralization, transparency, immutability, and auditability. Blocks contain transaction data, a hash of the previous block, and a timestamp. Blockchains use peer-to-peer networks and consensus mechanisms like proof-of-work or proof-of-stake to validate new blocks. Smart contracts allow terms of an agreement to be automatically executed when conditions are met. The first blockchain concept dates to 1991, with Bitcoin's launch in 2009 popularizing the technology which has since grown to include various applications and cryptocurrencies.
Blockchain 101 provides an overview of blockchain technology. It discusses the two main types of blockchains - public and private. Key events that drove blockchain interest include the 2008 Bitcoin whitepaper and Ethereum's launch in 2015. The technical underpinnings of blockchain, including hashing, Merkle trees, and proof of work are explained. Examples are given of how blockchain is being used or explored in areas like land registry, identity, shipping, and healthcare. The document recommends resources for learning more about blockchain and names several smart experts to follow.
The document discusses blockchain technology. It defines blockchain as a distributed database or ledger that stores information across a network of computers. It explains how blockchain works by structuring data into time-stamped blocks that are linked together in a chain. It then covers key aspects of blockchain like decentralization, transparency, security, and applications such as cryptocurrencies, smart contracts, and supply chain management. The benefits are highlighted as improved accuracy, lower costs, decentralization, and efficient transactions.
Blockchain In-Depth Tutorial for BeginnersSimplilearn
In this Blockchain In-depth Tutorial, you will learn everything related to blockchain and its related concepts like, bitcoin, mining, smart contracts, proof-of-Work, hashing, encryption, areas where blockchain is used with proper demonstrations. How to become a blockchain developer, what are the requirements for it, also what salary is offered to them and what companies want to hire them. At the end of this video I assure you that all your concepts related to Blockchain will be cleared.
What is Blockchain?
What is Bitcoin’s story?
Features of Blockchain
Use-Case: Blockchain and Banks
Byzantine Fault Tolerance
Adding 2 blocks at the same time
Areas where blockchain is used
The future of Blockchain
Blockchain Jobs
Use-case: Movie Ratings Smart Contract
Why do we need Blockchain?
Challenges in Blockchain
Healthcare Use-Cases
Government Use-Cases
Blockchain In KYC
Blockchain in Trade Finance
Who is a Blockchain Developer?
Types of Blockchain Developer
Steps to Become a Blockchain Developer
Obstacles in learning Blockchain
Salary of Blockchain Developers
How are companies using Blockchain?
🔥Free Blockchain Developer Course with Completion Certificate: https://www.simplilearn.com/learn-blo...
✅Subscribe to our Channel to learn more about the top Technologies: https://bit.ly/2VT4WtH
⏩ Check out the Blockchain training videos: https://www.youtube.com/watch?v=yubzJ...
#BlockchainIn-DepthTutorialforBeginners #Blockchain #BlockchainTutorialForBeginners #BlockchainDeveloper #CryptocurrencyTrends2022 #BlockchainAndCryptocurrencyTrends2022 #BlockchainTrends #CryptocurrencyTrends #Cryptocurrency #BlockchainTechnology #Crypto #Simplilearn
To know about cryptocurrency and Blockchain, visit: https://www.simplilearn.com/blockchai...
About Simplilearn Blockchain Certification Training:
Simplilearn’s Blockchain Certification Training has been designed for developers who want to decipher the global craze surrounding Blockchain, Bitcoin, and cryptocurrencies. You’ll learn the core structure and technical mechanisms of Bitcoin, Ethereum, Hyperledger, and Multichain Blockchain platforms, use the latest tools to build Blockchain applications, set up your own private Blockchain, deploy smart contracts on Ethereum and gain practical experience with real-world projects.
Why learn Blockchain?
Blockchain technology is the brainchild of Satoshi Nakamoto, which enables digital information to be distributed. A network of computing nodes makes up the Blockchain. Durability, robustness, success rate, transparency, and incorruptibility are some of the enticing characteristics of Blockchain. By design, Blockchain is a decentralized technology that is used by a global network of computers to manage Bitcoin transactions easily. Many new business applications will result in the usage of Blockchain, such as Crowdfunding, smart contracts, supply chain auditing, Internet of Things(IoT), etc.
After completing this course, you will be able to:
1. Apply Bitcoin and Bloc
201811 Bitcoin, Blockchain and the Technology behind CryptocurrenciesPaperchain
Half Moon Seminer presentation for CLE credits.
Goes through the technologies that underly blockchain systems, smart contracts, tokens and their applications across a number of industry verticals.
Sohana Amreen presented on blockchain technology. She explained that blockchain is a distributed, decentralized, transparent and chronological database of transactions stored in blocks. Blockchain uses cryptography to allow transactions to be securely recorded in a public ledger without the need for centralized oversight. She discussed the history of blockchain from Bitcoin's inception in 2008 to current applications beyond cryptocurrency like smart contracts, cloud storage and voting.
Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies anupriti
Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies was held at G D Goenka University, Sohna Road,Gurgaon on 22nd Feb 2018.Sharing here the presentation I gave for info.Readers may contact me for any clarifications on the subject content please.
Blockchain is the technology that supports cryptocurrencies such as Bitcoin and Ethereum and this platform has the potential to be a revolution in the business world. There are many advantages that blockchain has to offer and more and more businesses and organizations across the world are taking a serious look at it.
Just because blockchain is associated with cryptocurrencies does not mean that there are not other applications for it. A lot of movers and shakers in the business world have already realized the potential that the blockchain technology has to offer. Some are using it for their business processes right now and seeing some spectacular results.
The use of blockchain in the business world can add different layers of security and fast transaction processing for example. Not only that, blockchain can be used for the processing of payments and reduce the costs of conventional methods.
There are almost unlimited possibilities with blockchain technology. Some businesses and organizations are already benefiting from it and there is no reason why you cannot do the same. Applying the blockchain platform to your business could be one of the best moves that you ever make.
In this powerful report, we will take a deep dive into blockchain and show you how you can benefit from applying it in your business. You can apply the technology to your existing business and by understanding how it works and what it can offer you may come up with some new business ideas.
In the next section, we will discuss the fundamentals of blockchain so that you have a good understanding of what it is and how it works…
Blockchain data structures and fundamentalCodium Club
The blockchain is a growing list of records called blocks which are linked using cryptography. So, here's a small introductory presentation to describe the basic fundamentals and data structure of the blockchain.
Blockchain Power is a new powerful report that many business owners will want to have. You can use this report as a very appealing lead magnet as many businesses want to know more about blockchain. In the report readers will learn what blockchain really is and what it isn’t. They will also be provided with a non-technical overview of how blockchain works.
Blockchain is a decentralized ledger or list of all transactions across a peer-to-peer network. It underlies technologies like Bitcoin and has potential to disrupt many business processes. No single user controls the blockchain, transactions are broadcast to the network and validated through consensus. The author of the blockchain concept is unknown, thought to use the pseudonym Satoshi Nakamoto. Blockchains use techniques like proof-of-work to serialize changes and achieve distributed consensus to maintain integrity without centralized authority.
How Blockchain Technology Is Evolving In The CloudShikhaKonda
https://go-dgtl.com/whitepaper/how-blockchain-technology-is-evolving-in-the-cloud/?utm_source=offpage&utm_medium=thirdparty&utm_campaign=alo-seo - Cloud and blockchain are increasingly becoming the most valuable combinations to enhance the security of enterprise data living on the cloud. Learn more
How Blockchain Technology Is Evolving In The Cloud - GoDgtl.pdfPeeterParkar
Blockchain technology is evolving to provide security benefits when used with cloud computing. Major cloud platforms like Amazon, Google, and Microsoft now offer blockchain-as-a-service (BaaS) to securely store data in the cloud using blockchain's decentralized, immutable ledger. Blockchain addresses cloud computing's security risks like data loss and lack of transparency. Its use in the cloud is expected to grow significantly, expanding to applications in digital identity, payments, supply chain management, and more.
Blockchain is a distributed digital ledger that records transactions across a peer-to-peer network in a way that is immutable, transparent, and secure. It allows transactions to be recorded without a central authority by distributing the ledger across the entire network. Each transaction is grouped into blocks that are cryptographically linked together in a chain. The decentralized nature of blockchain makes it difficult to hack or corrupt the ledger. While blockchain first emerged with Bitcoin, the technology can be applied beyond cryptocurrencies to provide trust and transparency to other types of transactions.
Do a research and make a PowerPoint about Insulation for architectDustiBuckner14
Do a research and make a PowerPoint about Insulation for architecture
· What is Insulation?
· units of measurement and formulas
· Types of insulation and location of use
· Dew point
· Show examples for each type with pros and cons
· Sketch wall and detail sections and show each layer
· Provide some Research with links
Creative Commons Non Commercial CC-BY-NC: This article is distributed under the terms of the Creative Commons Attribution-
NonCommercial 3.0 License (http://www.creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use,
reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and
Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
VikalPa • VolUMe 44 • iSSUe 1 • JanUaRY-MaRch 2019 1
Blockchain in Finance
Jayanth Rama Varma
P E R S P E C T I V E S
KEY WORDS
Blockchain
Distributed Ledger
DLT
Crypto Currency
includes research articles
that focus on the analysis and
resolution of managerial and
academic issues based on
analytical and empirical or
case research
B
lockchain—the decentralized replicated ledger technology that underlies
Bitcoin and other cryptocurrencies—provides a potentially attractive alterna-
tive way to organize modern finance. Currently, the financial system depends
on a number of centralized trusted intermediaries: central counter parties (CCPs)
guarantee trades in exchanges; central securities depositories (CSDs) provide secu-
rities settlement; the Society for Worldwide Interbank Financial Telecommunication
(SWIFT) intermediates global transfer of money; CLS Bank handles the settlement
of foreign exchange transactions, a handful of banks dominate correspondent
banking, and an even smaller number provide custodial services to large invest-
ment institutions. Until a decade ago, it was commonly assumed that the finan-
cial strength and sound management of these central hubs ensured that they were
extremely unlikely to fail. More importantly, it was assumed that they were too big to
fail (TBTF), so that the government would step in and bail them out if they did fail.
The Global Financial Crisis of 2007–2008 shattered these assumptions as many large
banks in the most advanced economies of the world either failed or were very reluc-
tantly bailed out. The Eurozone Crisis of 2010–2012 stoked the fear that even rich
country sovereigns could potentially default on their obligations. Finally, repeated
instances of hacking of the computers of large financial institutions is another factor
that has destroyed trust. When trust in the central hubs of finance is being increas-
ingly questioned, decentralized systems like the blockchain that reduce the need for
such trust become attractive.
It is no coincidence that Bitcoin was launched shortly after the failure of Lehman
that marked the peak of the global financial crisis. Over the subsequent decade,
cryptocurrenc ...
38 C O M M U N I C AT I O N S O F T H E A C M M A.docxdomenicacullison
38 C O M M U N I C AT I O N S O F T H E A C M | M A R C H 2 0 1 9 | V O L . 6 2 | N O . 3
practice
I T I S D I F F I C U LT these days to avoid hearing about
blockchain. Blockchain is going to be the foundation
of a new business world based on smart contracts.
It is going to allow everyone to trace the provenance of
their food, the parts in the items they buy, or the ideas
they hear. It will change the way we work, the way the
economy runs, and the way we live in general.
Despite the significant potential of blockchain, it is
also difficult to find a consistent description of what
it really is. A recent Google search for “blockchain
technical papers” returned nothing but white
papers for the first three screens; not a single paper
is peer-reviewed. One of the best discussions of the
technology itself is from the National Institute of
Standards and Technology, but at 50-plus pages, it is a
bit much for a quick read.9
The purpose of this article is to look
at the basics of blockchain: the indi-
vidual components, how those com-
ponents fit together, and what changes
might be made to solve some of the
problems with blockchain technology.
This technology is far from monolithic;
some of the techniques can be used (at
surprising savings of resources and ef-
fort) if other parts are cut away.
Because there is no single set of
technical specifications, some systems
that claim to be blockchain instances
will differ from the system described
here. Much of this description is taken
from the original blockchain paper.6
While details may differ, the main
ideas stay the same.
Goals of Blockchain
The original objective of the block-
chain system was to support “an elec-
tronic payment system based on cryp-
tographic proof instead of trust …”6
While the scope of use has grown con-
siderably, the basic goals and require-
ments have remained consistent.
The first of these goals is to ensure
the anonymity of blockchain’s users.
This is accomplished by use of a pub-
lic/private key pair, in a fashion that is
reasonably well known and not rein-
vented by the blockchain technology.
Each participant is identified by the
public key, and authentication is ac-
complished through signing with the
private key. Since this is not specific
to blockchain, it is not considered
further here.
The second goal is to provide a pub-
lic record or ledger of a set of transac-
tions that cannot be altered once veri-
fied and agreed to. This was originally
designed to keep users of electronic
currency from double-spending and to
allow public audit of all transactions.
The ledger is a record of what transac-
tions have taken place, and the order
of those transactions. The use of this
ledger for verification of transactions
other than the exchange of electronic
cash has been the main extension of
the blockchain technology.
The final core goal is for the system
A Hitchhiker’s
Guide to the
Blockchain
Un.
Blockchain is the technology that underpins cryptocurrencies like Bitcoin. It uses cryptography and a peer-to-peer network to securely record transactions in a distributed ledger called a blockchain. The blockchain grows as "blocks" of new transactions are added together through a consensus mechanism. Once recorded, data in the blockchain cannot be altered, which provides transparency and immutability. Blockchain has various applications including banking, payments, voting, and more by facilitating transactions without middlemen and reducing the risk of hacking or fraud.
Blockchain is the technology that underpins cryptocurrencies like Bitcoin. It uses cryptography and a peer-to-peer network to securely record transactions in a distributed ledger called a blockchain. The blockchain grows as "blocks" of new transactions are added together in a chain, with each block timestamped and linked to the previous one. This allows transactions to be permanently recorded and verified in an open yet secure distributed manner without the need for a centralized authority. Potential applications of blockchain technology include banking, payments, voting, and more.
In this case study, we are providing information about the Introduction of Blockchain Technology, Bitcoin and its environment setup, Ethereum coin, other cryptocurrencies, Bitcoin in education, and a case study of healthcare using blockchain.
A Complete Beginners Guide to Blockchain Technology Part 2 of 6. Slides from the #StartingBlock2015 tour by @blockstrap
Part 1: http://www.slideshare.net/Blockstrap/cbgtbt-part-1-workshop-introduction-primer
Part 2: http://www.slideshare.net/Blockstrap/02-blockchains-101
Part 3: http://www.slideshare.net/Blockstrap/03-transactions-101
Part 4: http://www.slideshare.net/Blockstrap/cbgtbt-part-4-mining
Part 5: http://www.slideshare.net/Blockstrap/05-blockchains-102
Part 6: http://www.slideshare.net/Blockstrap/06-transactions-102
The document provides an overview of Bitcoin and blockchain technology. It discusses the evolution of currency from bartering to cashless societies. Bitcoin is defined as a decentralized peer-to-peer network using a public transaction ledger called the blockchain. Key aspects of Bitcoin like its history, transactions, mining, and blockchain are summarized. The document also covers blockchain applications and concludes with a question and answer section.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
The document discusses blockchain technology. It defines blockchain as a distributed database or ledger that stores information across a network of computers. It explains how blockchain works by structuring data into time-stamped blocks that are linked together in a chain. It then covers key aspects of blockchain like decentralization, transparency, security, and applications such as cryptocurrencies, smart contracts, and supply chain management. The benefits are highlighted as improved accuracy, lower costs, decentralization, and efficient transactions.
Blockchain In-Depth Tutorial for BeginnersSimplilearn
In this Blockchain In-depth Tutorial, you will learn everything related to blockchain and its related concepts like, bitcoin, mining, smart contracts, proof-of-Work, hashing, encryption, areas where blockchain is used with proper demonstrations. How to become a blockchain developer, what are the requirements for it, also what salary is offered to them and what companies want to hire them. At the end of this video I assure you that all your concepts related to Blockchain will be cleared.
What is Blockchain?
What is Bitcoin’s story?
Features of Blockchain
Use-Case: Blockchain and Banks
Byzantine Fault Tolerance
Adding 2 blocks at the same time
Areas where blockchain is used
The future of Blockchain
Blockchain Jobs
Use-case: Movie Ratings Smart Contract
Why do we need Blockchain?
Challenges in Blockchain
Healthcare Use-Cases
Government Use-Cases
Blockchain In KYC
Blockchain in Trade Finance
Who is a Blockchain Developer?
Types of Blockchain Developer
Steps to Become a Blockchain Developer
Obstacles in learning Blockchain
Salary of Blockchain Developers
How are companies using Blockchain?
🔥Free Blockchain Developer Course with Completion Certificate: https://www.simplilearn.com/learn-blo...
✅Subscribe to our Channel to learn more about the top Technologies: https://bit.ly/2VT4WtH
⏩ Check out the Blockchain training videos: https://www.youtube.com/watch?v=yubzJ...
#BlockchainIn-DepthTutorialforBeginners #Blockchain #BlockchainTutorialForBeginners #BlockchainDeveloper #CryptocurrencyTrends2022 #BlockchainAndCryptocurrencyTrends2022 #BlockchainTrends #CryptocurrencyTrends #Cryptocurrency #BlockchainTechnology #Crypto #Simplilearn
To know about cryptocurrency and Blockchain, visit: https://www.simplilearn.com/blockchai...
About Simplilearn Blockchain Certification Training:
Simplilearn’s Blockchain Certification Training has been designed for developers who want to decipher the global craze surrounding Blockchain, Bitcoin, and cryptocurrencies. You’ll learn the core structure and technical mechanisms of Bitcoin, Ethereum, Hyperledger, and Multichain Blockchain platforms, use the latest tools to build Blockchain applications, set up your own private Blockchain, deploy smart contracts on Ethereum and gain practical experience with real-world projects.
Why learn Blockchain?
Blockchain technology is the brainchild of Satoshi Nakamoto, which enables digital information to be distributed. A network of computing nodes makes up the Blockchain. Durability, robustness, success rate, transparency, and incorruptibility are some of the enticing characteristics of Blockchain. By design, Blockchain is a decentralized technology that is used by a global network of computers to manage Bitcoin transactions easily. Many new business applications will result in the usage of Blockchain, such as Crowdfunding, smart contracts, supply chain auditing, Internet of Things(IoT), etc.
After completing this course, you will be able to:
1. Apply Bitcoin and Bloc
201811 Bitcoin, Blockchain and the Technology behind CryptocurrenciesPaperchain
Half Moon Seminer presentation for CLE credits.
Goes through the technologies that underly blockchain systems, smart contracts, tokens and their applications across a number of industry verticals.
Sohana Amreen presented on blockchain technology. She explained that blockchain is a distributed, decentralized, transparent and chronological database of transactions stored in blocks. Blockchain uses cryptography to allow transactions to be securely recorded in a public ledger without the need for centralized oversight. She discussed the history of blockchain from Bitcoin's inception in 2008 to current applications beyond cryptocurrency like smart contracts, cloud storage and voting.
Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies anupriti
Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies was held at G D Goenka University, Sohna Road,Gurgaon on 22nd Feb 2018.Sharing here the presentation I gave for info.Readers may contact me for any clarifications on the subject content please.
Blockchain is the technology that supports cryptocurrencies such as Bitcoin and Ethereum and this platform has the potential to be a revolution in the business world. There are many advantages that blockchain has to offer and more and more businesses and organizations across the world are taking a serious look at it.
Just because blockchain is associated with cryptocurrencies does not mean that there are not other applications for it. A lot of movers and shakers in the business world have already realized the potential that the blockchain technology has to offer. Some are using it for their business processes right now and seeing some spectacular results.
The use of blockchain in the business world can add different layers of security and fast transaction processing for example. Not only that, blockchain can be used for the processing of payments and reduce the costs of conventional methods.
There are almost unlimited possibilities with blockchain technology. Some businesses and organizations are already benefiting from it and there is no reason why you cannot do the same. Applying the blockchain platform to your business could be one of the best moves that you ever make.
In this powerful report, we will take a deep dive into blockchain and show you how you can benefit from applying it in your business. You can apply the technology to your existing business and by understanding how it works and what it can offer you may come up with some new business ideas.
In the next section, we will discuss the fundamentals of blockchain so that you have a good understanding of what it is and how it works…
Blockchain data structures and fundamentalCodium Club
The blockchain is a growing list of records called blocks which are linked using cryptography. So, here's a small introductory presentation to describe the basic fundamentals and data structure of the blockchain.
Blockchain Power is a new powerful report that many business owners will want to have. You can use this report as a very appealing lead magnet as many businesses want to know more about blockchain. In the report readers will learn what blockchain really is and what it isn’t. They will also be provided with a non-technical overview of how blockchain works.
Blockchain is a decentralized ledger or list of all transactions across a peer-to-peer network. It underlies technologies like Bitcoin and has potential to disrupt many business processes. No single user controls the blockchain, transactions are broadcast to the network and validated through consensus. The author of the blockchain concept is unknown, thought to use the pseudonym Satoshi Nakamoto. Blockchains use techniques like proof-of-work to serialize changes and achieve distributed consensus to maintain integrity without centralized authority.
How Blockchain Technology Is Evolving In The CloudShikhaKonda
https://go-dgtl.com/whitepaper/how-blockchain-technology-is-evolving-in-the-cloud/?utm_source=offpage&utm_medium=thirdparty&utm_campaign=alo-seo - Cloud and blockchain are increasingly becoming the most valuable combinations to enhance the security of enterprise data living on the cloud. Learn more
How Blockchain Technology Is Evolving In The Cloud - GoDgtl.pdfPeeterParkar
Blockchain technology is evolving to provide security benefits when used with cloud computing. Major cloud platforms like Amazon, Google, and Microsoft now offer blockchain-as-a-service (BaaS) to securely store data in the cloud using blockchain's decentralized, immutable ledger. Blockchain addresses cloud computing's security risks like data loss and lack of transparency. Its use in the cloud is expected to grow significantly, expanding to applications in digital identity, payments, supply chain management, and more.
Blockchain is a distributed digital ledger that records transactions across a peer-to-peer network in a way that is immutable, transparent, and secure. It allows transactions to be recorded without a central authority by distributing the ledger across the entire network. Each transaction is grouped into blocks that are cryptographically linked together in a chain. The decentralized nature of blockchain makes it difficult to hack or corrupt the ledger. While blockchain first emerged with Bitcoin, the technology can be applied beyond cryptocurrencies to provide trust and transparency to other types of transactions.
Do a research and make a PowerPoint about Insulation for architectDustiBuckner14
Do a research and make a PowerPoint about Insulation for architecture
· What is Insulation?
· units of measurement and formulas
· Types of insulation and location of use
· Dew point
· Show examples for each type with pros and cons
· Sketch wall and detail sections and show each layer
· Provide some Research with links
Creative Commons Non Commercial CC-BY-NC: This article is distributed under the terms of the Creative Commons Attribution-
NonCommercial 3.0 License (http://www.creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use,
reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and
Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
VikalPa • VolUMe 44 • iSSUe 1 • JanUaRY-MaRch 2019 1
Blockchain in Finance
Jayanth Rama Varma
P E R S P E C T I V E S
KEY WORDS
Blockchain
Distributed Ledger
DLT
Crypto Currency
includes research articles
that focus on the analysis and
resolution of managerial and
academic issues based on
analytical and empirical or
case research
B
lockchain—the decentralized replicated ledger technology that underlies
Bitcoin and other cryptocurrencies—provides a potentially attractive alterna-
tive way to organize modern finance. Currently, the financial system depends
on a number of centralized trusted intermediaries: central counter parties (CCPs)
guarantee trades in exchanges; central securities depositories (CSDs) provide secu-
rities settlement; the Society for Worldwide Interbank Financial Telecommunication
(SWIFT) intermediates global transfer of money; CLS Bank handles the settlement
of foreign exchange transactions, a handful of banks dominate correspondent
banking, and an even smaller number provide custodial services to large invest-
ment institutions. Until a decade ago, it was commonly assumed that the finan-
cial strength and sound management of these central hubs ensured that they were
extremely unlikely to fail. More importantly, it was assumed that they were too big to
fail (TBTF), so that the government would step in and bail them out if they did fail.
The Global Financial Crisis of 2007–2008 shattered these assumptions as many large
banks in the most advanced economies of the world either failed or were very reluc-
tantly bailed out. The Eurozone Crisis of 2010–2012 stoked the fear that even rich
country sovereigns could potentially default on their obligations. Finally, repeated
instances of hacking of the computers of large financial institutions is another factor
that has destroyed trust. When trust in the central hubs of finance is being increas-
ingly questioned, decentralized systems like the blockchain that reduce the need for
such trust become attractive.
It is no coincidence that Bitcoin was launched shortly after the failure of Lehman
that marked the peak of the global financial crisis. Over the subsequent decade,
cryptocurrenc ...
38 C O M M U N I C AT I O N S O F T H E A C M M A.docxdomenicacullison
38 C O M M U N I C AT I O N S O F T H E A C M | M A R C H 2 0 1 9 | V O L . 6 2 | N O . 3
practice
I T I S D I F F I C U LT these days to avoid hearing about
blockchain. Blockchain is going to be the foundation
of a new business world based on smart contracts.
It is going to allow everyone to trace the provenance of
their food, the parts in the items they buy, or the ideas
they hear. It will change the way we work, the way the
economy runs, and the way we live in general.
Despite the significant potential of blockchain, it is
also difficult to find a consistent description of what
it really is. A recent Google search for “blockchain
technical papers” returned nothing but white
papers for the first three screens; not a single paper
is peer-reviewed. One of the best discussions of the
technology itself is from the National Institute of
Standards and Technology, but at 50-plus pages, it is a
bit much for a quick read.9
The purpose of this article is to look
at the basics of blockchain: the indi-
vidual components, how those com-
ponents fit together, and what changes
might be made to solve some of the
problems with blockchain technology.
This technology is far from monolithic;
some of the techniques can be used (at
surprising savings of resources and ef-
fort) if other parts are cut away.
Because there is no single set of
technical specifications, some systems
that claim to be blockchain instances
will differ from the system described
here. Much of this description is taken
from the original blockchain paper.6
While details may differ, the main
ideas stay the same.
Goals of Blockchain
The original objective of the block-
chain system was to support “an elec-
tronic payment system based on cryp-
tographic proof instead of trust …”6
While the scope of use has grown con-
siderably, the basic goals and require-
ments have remained consistent.
The first of these goals is to ensure
the anonymity of blockchain’s users.
This is accomplished by use of a pub-
lic/private key pair, in a fashion that is
reasonably well known and not rein-
vented by the blockchain technology.
Each participant is identified by the
public key, and authentication is ac-
complished through signing with the
private key. Since this is not specific
to blockchain, it is not considered
further here.
The second goal is to provide a pub-
lic record or ledger of a set of transac-
tions that cannot be altered once veri-
fied and agreed to. This was originally
designed to keep users of electronic
currency from double-spending and to
allow public audit of all transactions.
The ledger is a record of what transac-
tions have taken place, and the order
of those transactions. The use of this
ledger for verification of transactions
other than the exchange of electronic
cash has been the main extension of
the blockchain technology.
The final core goal is for the system
A Hitchhiker’s
Guide to the
Blockchain
Un.
Blockchain is the technology that underpins cryptocurrencies like Bitcoin. It uses cryptography and a peer-to-peer network to securely record transactions in a distributed ledger called a blockchain. The blockchain grows as "blocks" of new transactions are added together through a consensus mechanism. Once recorded, data in the blockchain cannot be altered, which provides transparency and immutability. Blockchain has various applications including banking, payments, voting, and more by facilitating transactions without middlemen and reducing the risk of hacking or fraud.
Blockchain is the technology that underpins cryptocurrencies like Bitcoin. It uses cryptography and a peer-to-peer network to securely record transactions in a distributed ledger called a blockchain. The blockchain grows as "blocks" of new transactions are added together in a chain, with each block timestamped and linked to the previous one. This allows transactions to be permanently recorded and verified in an open yet secure distributed manner without the need for a centralized authority. Potential applications of blockchain technology include banking, payments, voting, and more.
In this case study, we are providing information about the Introduction of Blockchain Technology, Bitcoin and its environment setup, Ethereum coin, other cryptocurrencies, Bitcoin in education, and a case study of healthcare using blockchain.
A Complete Beginners Guide to Blockchain Technology Part 2 of 6. Slides from the #StartingBlock2015 tour by @blockstrap
Part 1: http://www.slideshare.net/Blockstrap/cbgtbt-part-1-workshop-introduction-primer
Part 2: http://www.slideshare.net/Blockstrap/02-blockchains-101
Part 3: http://www.slideshare.net/Blockstrap/03-transactions-101
Part 4: http://www.slideshare.net/Blockstrap/cbgtbt-part-4-mining
Part 5: http://www.slideshare.net/Blockstrap/05-blockchains-102
Part 6: http://www.slideshare.net/Blockstrap/06-transactions-102
The document provides an overview of Bitcoin and blockchain technology. It discusses the evolution of currency from bartering to cashless societies. Bitcoin is defined as a decentralized peer-to-peer network using a public transaction ledger called the blockchain. Key aspects of Bitcoin like its history, transactions, mining, and blockchain are summarized. The document also covers blockchain applications and concludes with a question and answer section.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
2. About The Course
• blockchain fundamentals
• blockchain implementation in Java
More and more people are looking to invest in Bitcoin and other cryptocurrencies, in hopes of making it rich.
While the buzz and hype surrounding cryptocurrency don’t seem like it is going to die down anytime soon, the underlying
foundation of Bitcoin is starting to take center stage.
If you’re like a majority of the population, you probably have a lot of questions about blockchain technology and the
hype surrounding the emerging technology.
Blockchain Secrets
click here
3. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
4. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
wants to buy a car wants to sell a car
5. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
wants to buy a car wants to sell a car
PROBLEM: no trust
6. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
wants to buy a car wants to sell a car
PROBLEM: no trust
TRUSTED THIRD PARTY
(centralized system such as governments)
the buyer has to notify
the government that now
he owns a car
the seller has to notify
the government that
he sold his car
7. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
wants to buy a car wants to sell a car
PROBLEM: no trust
BLOCKCHAIN TECHNOLOGY CAN GET RID
OF THESE THIRD PARTIES !!!
8. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
DECENTRALIZED NETWORK OF CAR BUYERS
AND SELLERS WITH BLOCKCHAIN !!!
it is a trustless system without
any third party
(the blockchain itself guarantees trust)
9. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and to use decentralized ones instead)
A wants to send money to B B want to receive money from A
PROBLEM: no trust
TRUSTED THIRD PARTY
(centralized system such as bank)
sender has to notify the bank
to send $x to B the trusted third party (bank)
will send money to B
10. Blockchain - motivation
At the moment centralized system are dominating
~ the aim of the blockchain technology is to get rid of these
centralized systems (and use decentralized ones instead)
DECENTRALIZED NETWORK OF CLIENTS
WITH BLOCKCHAIN !!!
it is a trustless system without
any third party
(the blockchain itself guarantees trust)
12. Blockchain
„A blockchain is a continuously growing list of records, called blocks,
which are linked and secured using cryptography”
it was first constructed by Stuart Haber and W. Scott Tornetta in 1991
blockchain is the underlying technology and data structure of cryptocurrencies
~ we can store for example transactions in the blocks
it is a linked list where the nodes are the blocks in the blockchain and the
references are hashes of the previous block in the chain
REFERENCES ARE CRYPTOGRAPHIC HASHES !!!
15. Blockchain
GENESIS
BLOCK
BLOCK #1 BLOCK #2 BLOCK #3 ...
Data: ...
Prev. Hash: 0000
Hash: 056FH
Data: ...
Prev. Hash: 056FH
Hash: HJI66
Data: ...
Prev. Hash: HJI66
Hash: ZU77F
Data: ...
Prev. Hash: ZU77F
Hash: 789BV
so the blockchain itself is a linked list with hash-pointers
every node in the blockchain has 2 hash values: own hash and
the hash value of the previous block
„Blocks form a linked list where the nodes are cryptographically linked together”
16. Blockchain – SHA256
So blocks in a blockchain use hash-pointers to reference the
previous node in the linked-list
~ we assign a hash to every node: this is how we identify them
How to calculate these hashes?
It is very similar to fingerprints: we identify every human with his/her fingerprint
~ we want to do the same but with the blocks in the blockchain
THE SHA256 HASHES ARE THE FINGERPRINTS OF THE BLOCKS !!!
SHA256 was constructed by the National Security Agency (NSA)
it is a generic cryptographic hash function: the input can be anything
and the output is a 256 bit long hexadecimal sequence
What is the input when dealing with blockchains? The given block is the input for the SHA256
17. Blockchain – SHA256
36f47ded94c31186f3a1d6c27fb7d607b47ff2a91b4e98d84e1e28ec583cedbd
Hexadecimal: [0:9] and [A:F] these are the possible values
it means there are 16 possibilities which can be represented
on 4 bits (24=16)
Output: 64 character hexadecimal string (independent of the input)
because the hash itself takes up 256 bits in the memory and
every character’s size is 4 bits thats why the length
of the output is 64
18. Blockchain – SHA256
FEATURES OF HASHING ALGORITHMS
1.) deterministic: it means that if we apply to same hash-function (SHA256) on
the exact same input then the output must be the same
2.) one-way: it is easy to generate the hash with the given hashing algorithm but
on the other hand it is extremely hard (time-consuming) to restore the original input
~ it is like a trap-door function
3.) collision-free: there are no collisions in SHA256 (ok there are but with extremely low probability)
It means that no two different inputs share the same output hash
~ and this is good: we want to make these hashes unique, this
is how we identify a block in the blockchain
4.) avalanche effect: a little change in the input results in a completely different output hash
~ otherwise a cryptoanalyst can make predictions about the input
based on the output exclusively
19. Blockchain – SHA256
Further articles/videos on the topic:
Implementation and pseudocode of the SHA256 algorithm:
https://www.movable-type.co.uk/scripts/sha256.html
SHA256 and collisions
https://crypto.stackexchange.com/questions/47809/why-havent-any-sha-256-collisions-been-found-yet?rq=1
20. Blockchain – immutable ledger
PROBLEM: no trust
TRUSTED THIRD PARTY
(centralized system such as banks)
In centralized systems there is a central database or server where
the data is stored (centralized ledger)
~ it has all the information (identity of users or transactions)
PROBLEM: if we hack the central database then its done
CENTRAL LEDGER
Transaction #1
Transaction #2
Transaction #3
Transaction #4
A wants to send money to B B want to receive money from A
sender has to notify the bank
to send $x to B
the trusted third party (bank)
will send money to B
21. Blockchain – immutable ledger
By the way this architecture is very similar to the client-server model
It is a centralized architecture: the server is the center
data (and the database) is present on a
single logical server
anyone with the right credentials (username/password)
can access these systems (databases for example)
22. Blockchain – immutable ledger
In decentralized systems there is NO central database or server where
the data is stored (decentralized ledger)
~ we are not able to hack the system: we should hack most of the nodes
in the network to do so
It is a P2P (peer-to-peer) decentralized
network of nodes
every node in the network have a copy of the blockchain
if someone tempers the data in a block: the cryptographic
hash changes as well so the pointers are broken
OK the hacker may change the hash values
in other blocks as well ...
EXTREMELY HARD TO HACK DECENTRALIZED SYSTEMS !!!
Data that has been written to a block cannot be changed
or erased: this is why it is called immutable
23. Blockchain – immutable ledger
the transactions
(blocks and the blockchain itself)
are visible to everyone in the network
(decentralized ledger)
30. Blockchain – immutable ledger
because of the decentralized
feature of the system the nodes
will notify the attacked node
that there is some inconsistency
33. Blockchain – mining
Mining is basically the most important concept in blockchain
as well as in cryptocurrencies (such as Bitcoin)
in a centralized system the
trusted third party (banks)
handle the transactions
(softwares and databases)
PROBLEM: in a decentralized system who will handle the transactions?
MINERS WILL HANDLE AND VERIFY THE TRANSACTIONS !!!
getting paid is not the aim of mining it is just the by-product
mining is the mechanism that allows the blockchain to be
a decentralized security
it is about finding the right hash values for the blocks and
adding these blocks to the blockchain
MINERS WILL ADD THE BLOCKS TO THE BLOCKCHAIN !!!
34. Blockchain – mining
GENESIS
BLOCK
BLOCK #1 BLOCK #2 BLOCK #3 ...
Data: ...
Prev. Hash: 0000
Hash: 056FH
Data: ...
Prev. Hash: 056FH
Hash: HJI66
Data: ...
Prev. Hash: HJI66
Hash: ZU77F
Data: ...
Prev. Hash: ZU77F
Hash: 789BV
miners find the hash values for the blocks
so they try to find the right hash values (computational heavy procedure)
37. Blockchain – mining
02d38ebf07b0ca1ed92f3cdce825df28d36d8fdc39904060d2c18b13c096edc
In this case there are 4 leading zeros in the hash: so the aim of mining is to
find an arbitrary hash with 4 leading zeros
why is it called difficulty? Because the more leading zeros are there,
the harder to find that given hash
P(finding hash with 1 leading zero) =
𝐡𝐚𝐬𝐡𝐞𝐬𝐰𝐢𝐭𝐡𝟏𝐥𝐞𝐚𝐝𝐢𝐧𝐠𝐳𝐞𝐫𝐨
𝐭𝐨𝐭𝐚𝐥𝐧𝐮𝐦𝐛𝐞𝐫𝐨𝐟𝐡𝐚𝐬𝐡𝐞𝐬
𝟏𝟔𝟔𝟑
𝟏𝟔𝟔𝟒
= 1/16 = 6.25%
=
38. Blockchain – mining
00d38ebf07b0ca1ed92f3cdce825df28d36d8fdc39904060d2c18b13c096edc
In this case there are 4 leading zeros in the hash: so the aim of mining is to
find an arbitrary hash with 4 leading zeros
why is it called difficulty? Because the more leading zeros are there,
the harder to find that given hash
P(finding hash with 2 leading zero) =
𝐡𝐚𝐬𝐡𝐞𝐬𝐰𝐢𝐭𝐡𝟐𝐥𝐞𝐚𝐝𝐢𝐧𝐠𝐳𝐞𝐫𝐨
𝐭𝐨𝐭𝐚𝐥𝐧𝐮𝐦𝐛𝐞𝐫𝐨𝐟𝐡𝐚𝐬𝐡𝐞𝐬
𝟏𝟔𝟔𝟐
𝟏𝟔𝟔𝟒
= 1/256 = 0.39%
=
39. Blockchain – mining
0000000000000000008f3cdce825df28d36d8fdc39904060d2c18b13c096edc
In this case there are 4 leading zeros in the hash: so the aim of mining is to
find an arbitrary hash with 4 leading zeros
why is it called difficulty? Because the more leading zeros are there,
the harder to find that given hash
P(finding hash with 18 leading zero) =
𝐡𝐚𝐬𝐡𝐞𝐬𝐰𝐢𝐭𝐡𝟏𝟖𝐥𝐞𝐚𝐝𝐢𝐧𝐠𝐳𝐞𝐫𝐨
𝐭𝐨𝐭𝐚𝐥𝐧𝐮𝐦𝐛𝐞𝐫𝐨𝐟𝐡𝐚𝐬𝐡𝐞𝐬
𝟏𝟔𝟒𝟔
𝟏𝟔𝟔𝟒
= 2.1x10-20%
=
(this is the actual difficulty of bitcoin)
40. Blockchain – mining
How to generate these hashes? We use all the information present in the block and
feed this data to the SHA256 algorithm to get the 64 characters long hash
GIVEN BLOCK IN
THE BLOCKCHAIN
block id
transaction(s)
previous hash
nonce
merkle root
we we use the data in the block BUT most of the data
is immutable: we can not change the ID or the transactions
but of course we have to change something to change the
hash (so the output of the SHA256 algorithm)
THIS IS WHY WE HAVE THE NONCE: we change the value thus
we change the SHA256 hash
41. Blockchain – mining
NONCE: „number only used once”
it is a 32 bit unsigned integer so the range is [0 - 4billion]
during the mining operation miners change the value of this nonce
Why is it good? Because for every possible value of the nonce the
miners get a new SHA256 hash
miners can not guess the value of the nonce (because of the avalanche-effect)
so usually they start with 0 and keep incrementing it by 1
(Why to make mining difficult? It is called proof of work)
42. Blockchain – consensus
Byzantine generals problem: illustrates the problem of how distributed consensus work
Blockchain nodes are synchronizing their data all the time
~ there is no central authority to approve the operations (transactions for example) so the
majority of the nodes should reach a consensus before updating the dibstributed ledger
THIS IS THE PROCESS OF CONSENSUS !!!
For example: a given miner adds a block to the blockchain
and the other nodes must reach a consensus
(whether to approve or to reject)
43. Blockchain – consensus
TWO GENERALS PROBLEM
GENERAL #1 GENERAL #2
ENEMY
The problem is that 2 generals plan to attack
the enemy’s city BUT somehow they have to
reach a consensus whether to attack or not
they have to use messages because
their camps are far apart
the messages can be lost
The problem is that the generals must reach a consensus to avoid total annihilation
Best-case scenario: both of them attacks in this case they can win the battle (or both retreive)
Worst-case scenario: just one of them attacks and the enemy wins
SOMEHOW THEY HAVE TO REACH A CONSENSUS !!!
(in this case the network itself can not be trusted)
46. Blockchain – consensus
GENERAL #1
wants to attack
GENERAL #2
#1 will attack
#2 want to attack
#1 will attack
#2 will attack
TWO GENERALS PROBLEM
47. Blockchain – consensus
GENERAL #1
wants to attack
GENERAL #2
#1 will attack
#2 want to attack
#1 will attack
#2 will attack
TWO GENERALS PROBLEM
48. Blockchain – consensus
GENERAL #1
wants to attack
GENERAL #2
#1 will attack
#2 want to attack
#1 will attack
#2 will attack
PROBLEM: this approach needs infinite number of messages between the generals
~ if last message is lost then #2 will not attack and #1 will attack
which means there is no consensus
(by the way there is no solution to this problem)
TWO GENERALS PROBLEM
49. Blockchain – consensus
CONCLUSION: so if the network is corrupted (and can not be trusted) there is
nothing we can do to reach a consensus
usually: the network can be statistically byzantine which means that somet
transmits the messages sometimes it does not
~ in this case we have to send 1000 messages to
sure one of them will reach the destin
TWO GENERALS PROBLEM
50. Blockchain – consensus
ASSUMPTION: the network itself works perfectly but the nodes can be corrupted
Question: how to reach consensus in a distributed network where
nodes can be corrupted (traitors)
BYZANTINE GENERALS PROBLEM
the traitors’ aim is to make sure there won’t
be any consensus (so some of the generals will attack
some of them will retreat so the enemy will win)
the generals (traitors as well) broadcast the messages
through the network
majority vote: every general selects an alternative
which have a majority (more than half of the votes)
[attack,attack,retreat,attack] ATTACK !!!
51. Blockchain – consensus
ASSUMPTION: the network itself works perfectly but the nodes can be corrupted
Question: how to reach consensus in a distributed network where
nodes can be corrupted (traitors)
BYZANTINE GENERALS PROBLEM
general #1 general #2
general #3
Attack! Attack!
Attack!
52. Blockchain – consensus
ASSUMPTION: the network itself works perfectly but the nodes can be corrupted
Question: how to reach consensus in a distributed network where
nodes can be corrupted (traitors)
BYZANTINE GENERALS PROBLEM
general #1 traitor
general #3
Attack! Attack!
Retreat!
NO CONSENSUS
53. Blockchain – consensus
ASSUMPTION: the network itself works perfectly but the nodes can be corrupted
Question: how to reach consensus in a distributed network where
nodes can be corrupted (traitors)
BYZANTINE GENERALS PROBLEM
general #1 traitor
general #3
Attack! Attack!
Retreat!
NO CONSENSUS
Lemma: there are no solutions (no consensus) for the
byzantine generals problem for 3n+1 generals
with greater than n traitors
if more than 1/3 of the generals are traitors then
there is no consensus (no solution)
54. Blockchain – consensus
How to make sure that all the transactions are valid and not created by hackers?
If 51% of the nodes in the network agrees on something then the transaction is accepted !!!
Approaches to handle fault tolerance (byzantine generals problem):
1.) proof of work
2.) proof of stake
DISTRIBUTED CONSENSUS
55. Blockchain – proof of work
Mining itself is made to be a difficult operation (computationally expensive)
hard to find the right hash BUT very easy (fast) to verify it
why does it solve the byzantine generals problem? Because the system makes it
very expensive to become a traitor
// it was first used to prevent spam emails: you’d have to perform a small amount of
proof of work and attach that in the header of the email + receiver can check
whether you’d put some work into that before you sent it
(spammer will not wait years to send >10k spam emails)
THE SYSTEM MAKES SURE THE OPERATIONS ARE EXPENSIVE ENOUGH !!!
56. Blockchain – proof of work
finding the „golden hash” is so expensive that it would make
it really costly for that person to attack the network
Why is it expensive? Computers and electricity
the original problem is that there is no way to trust everyone in the network
and proof-of-work (PoW) makes sure the miners do not cheat
„There is no way to trust that everyone in the network is honest, so there has
to be some way to prevent miners from creating new blocks that benefit themselves”
if a miner finds the right hash he/she gets a reward but only if the other miners
agree to accept that transaction (others can verify these easily with SHA256)
if a certain miner creates a fraudulent transaction then all the other miners
will refuse to accept it as a new block (so no point in creating a whole bunch of fraudulent blocks)
NASH-EQUILIBRIUM IS TO CREATE VALID BLOCKS (and this is what secures the networks)
57. Blockchain – proof of work
Disadvantages of PoW:
it is rather inefficient: the main problem it does not solve anything
(we set the leading zeros to be 18 just to make it a hard problem to solve)
so it is costly and wasteful (from an electricity perspective)
It cost half a billion dollars every year to secure the network (bitcoin) !!!
58. Cryptocurrency
PROBLEM: no trust
TRUSTED THIRD PARTY
(centralized system such as banks)
In centralized systems there is a central database or server where
the data is stored (centralized ledger)
~ it has all the information (identity of users or transactions)
PROBLEM: if we hack the central database then its done
CENTRAL LEDGER
transaction #1
transaction #2
transaction #3
transaction #4
A wants to send money to B B want to receive money from A
sender has to notify the bank
to send $x to B
the trusted third party (bank)
will send money to B
59. Cryptocurrency
There are two important layers in the bitcoin ecosystem:
1.) technology: the underlying technology is blockchain of course
2.) protocol: the protocol is the bitcoin protocol
~ bitcoin is a protocol and a cryptocurrency as well
It defines how the participants of the network communicate
with each other !!!
Bitcoin was constructed by Satoshi Nakamoto in 2009
“It is the first decentralized digital currency, as the system works without a
central bank or single administrator. The network is peer-to-peer
and transactions take place between users directly, without an intermediary.
These transactions are verified by network nodes through
the use of cryptography and recorded in a public distributed ledger called a blockchain”
61. Cryptocurrency
Bitcoin has a monetary policy which is controlled entirely by the software
and it contains two main parts:
1.) halving: the number of coins released into the system is halfed every 4 years
(it is halfed after every 210.000 blocks to be precise)
in 2009 the miners got 50 BTC after every block they verified
now in 2018 miners get 12.5 BTC after the same operation
2.) block frequency: it means how much does it take on average to mine a block
It is 10 minutes for bitcoin (15 sec for Ethereum)
62. Cryptocurrency
Difficulty is 18 at the moment in the bitcoin network
~ miners have to find hashes with 18 leading zeros
BITCOIN NETWORK MAKES SURE NEW BLOCKS ARE MINED IN EVERY 10 MINUTES
so the diffculty may increase or decrease
the difficulty increases: if it take <10min to mine a block
difficulty decreases: if it takes >10min to mine a block
63. Cryptocurrency
MEMPOOL
users add new transactions
(so pre-verified transactions)
are inserted into
the mempool
stores the transactions until a
given miner verifies them and
puts them into a block
miners take the
transactions and put them
into the blocks
64. Cryptocurrency
How do miners select the optimal set of transactions?
miners select M transactions from the mempool and create a new block
in the blockchain with these transactions (+find the right hash for the block)
every transaction has a transaction fee: this is the amount the user is willing to pay
for making the given transaction
It is basically an optimization problem (bin-packing): we have a bin with capacity C (1MB) and we have
N items with values t t ... t
1 2 N
What items to include in the bin to maximize the profit?
~ miners will sort the items and take the ones with the highest
transaction fees (note the miners get the sum of fees after mining)
MINER’S REWARD = X BTC + TRANSACTION FEES
96. Cryptocurrency – Merkle Tree
BLOCK
id: 5127654
timestamp: 1673576643
nonce: 13785
prev. hash: 000000DE543
merkle root: A43E5A4C
data:
id: 1 fee: 0.1 BTC
id: 3 fee: 0.3 BTC
id: 5 fee: 0.6 BTC
We use SHA256 hashes to identify a given block in the blockchain
Shall we include all the transactions in the header? Not that optimal ...
there can be 100-800 transactions within a single block
WE WANT TO REPRESENT ALL THESE TRANSACTIONS
WITH A SINGLE HASH !!!
we create a tree-like structure and store the root of this
tree in the header (entries are SHA256 hashes)
this Merkle-root can verify all the transaction and it is just
a single hash value
(if any of the transactions in the block changes then
the root’s value is changed as well: so this is why
we can verify all the transactions with the
Merkle-root exclusively)
101. Cryptocurrency – Merkle Tree
we represent a set of transactions with the help of a SHA256
so a 64 characters long hexadecimal string (the Merkle-root itself)
if a single detail in any of the transactions changes or even the order of the transactions
then the Merkle-root will change as well
+ it is part of the block’s header which forms the hash of the block
(after applying the SHA256 algorithm)
IT IS THE CRYPTOGRAPHIC PROOF OF WHICH TRANSACTIONS ARE IN THE BLOCK
without the Merkle-root in the block’s header: we would not have proof of which transactions
are included in the given block and that their contents have not been tampered with
102. Cryptocurrency – Elliptic Curve Cryptography
There is a huge problem: all the data is public ...
Somehow we have to encrypt the transactions and have to make sure
that other nodes in the network can verify these transactions !!!
bitcoin uses ECDSA (Elliptic Curve Digital Signature Algorithm) to ensure that
funds can only be spent by their rightful owners
PRIVATE KEY it is a secret number (256 bits integer) known only to the person that generated it
~ we can sign a given transaction with the private key
PUBLIC KEY it is generated from the private key and no need to keep it secret
It is extremely hard to get the private key from the public key
(public key is a 2D point coordinate on an elliptic curve)
we can verify the message (that has the signature) with the
help of the public key
103. Cryptocurrency – Elliptic Curve Cryptography
TRANSACTION
sender
receiver
amount
private key
of the owner
TRANSACTION
sender
receiver
amount
signature
...
anybody can verify the signature
and the transactions using
the public key
verify(transaction, publicKey)
104. Cryptocurrency – Elliptic Curve Cryptography
We identify wallets with the help of public keys
~ so when sending BTCs we have to use public keys
There is another layer of security: with RIPEMD we can generate a 160 bit long
hash which is called the address
WE CAN USE THIS ADDRESS WHEN TRANSFERRING MONEY TO A WALLET
105. Cryptocurrency - UTXOs
There may be several transactions in the cryprocurrency system
Daniel me 0.01 BTC
Adam me 0.2 BTC
Kevin me 0.1 BTC
these are called unspent
transaction outputs (UTXOs)
The problem: there is no account in the cryptocurrency network
~ we can calculate the balance of a given user (wallet) based on the UTXOs !!!
we can use previous transactions during the actual transaction
so the output of a transaction will be the input of another transaction
TRANSACTION INPUT AMOUNT = TRANSACTION OUTPUT AMOUNT
106. Cryptocurrency - UTXOs
There may be several transactions in the cryprocurrency system
Daniel me 0.01 BTC
Adam me 0.2 BTC
Kevin me 0.1 BTC
these are called unspent
transaction outputs (UTXOs)
I want to buy a computer for 0.25 BTC: I can use the unspent transactions of mine
~ we have to update the UTXOs because we make a transaction
107. Cryptocurrency - UTXOs
There may be several transactions in the cryprocurrency system
Daniel me 0.01 BTC
Adam me 0.2 BTC
Kevin me 0.1 BTC
these are called unspent
transaction outputs (UTXOs)
I want to buy a computer for 0.25 BTC: I can use the unspent transactions of mine
~ we have to update the UTXOs because we make a transaction
NEW TRANSACTION
INPUT OUTPUT
Adam me 0.2 BTC
Kevin me 0.1 BTC
me computer shop 0.25 BTC
me me 0.05 BTC
108. Cryptocurrency - UTXOs
There may be several transactions in the cryprocurrency system
Daniel me 0.01 BTC
Adam me 0.2 BTC
Kevin me 0.1 BTC
these are called unspent
transaction outputs (UTXOs)
I want to buy a computer for 0.25 BTC: I can use the unspent transactions of mine
~ we have to update the UTXOs because we make a transaction
NEW TRANSACTION
INPUT OUTPUT
Adam me 0.2 BTC
Kevin me 0.1 BTC
me computer shop 0.25 BTC
me me 0.05 BTC
109. Cryptocurrency - UTXOs
There may be several transactions in the cryprocurrency system
Daniel me 0.01 BTC
these are called unspent
transaction outputs (UTXOs)
I want to buy a computer for 0.25 BTC: I can use the unspent transactions of mine
~ we have to update the UTXOs because we make a transaction
NEW TRANSACTION
INPUT OUTPUT
Adam me 0.2 BTC
Kevin me 0.1 BTC
me computer shop 0.25 BTC
me me 0.05 BTC
110. Cryptocurrency - UTXOs
There may be several transactions in the cryprocurrency system
Daniel me 0.01 BTC
these are called unspent
transaction outputs (UTXOs)
I want to buy a computer for 0.25 BTC: I can use the unspent transactions of mine
~ we have to update the UTXOs because we make a transaction
NEW TRANSACTION
INPUT OUTPUT
Adam me 0.2 BTC
Kevin me 0.1 BTC
me computer shop 0.25 BTC
me me 0.05 BTC
me shop 0.25 BTC
me me 0.05 BTC
111. Cryptocurrency - wallets
Bitcoin wallet is where the bitcoins are stores BUT actually bitcoins are not stored anywhere
~ there are the blockchain with the transactions and thats all ...
in a centralized system the database stores the balance for every client
How to end up with a balance concerning a given wallet?
(so how to find out how much money does a user have)
WE CAN CALCULATE THE BALANCE BASED ON THE UTXOS !!!
Daniel me 0.01 BTC
me shop 0.25 BTC
me me 0.05 BTC
We just have to consider the unspent transaction
outputs that belong to us + sum up the BTC values
BALANCE = 0.06 BTC
112. Cryptocurrency – 51% Attack
First of all, let’s discuss the competing chains problem
it may happen that two or more blocks are mined at the same time
in different parts of the network
these are broadcasted BUT there is a problem ... there are more than one
blockchains. What to accept?
IT IS VERY SIMILAR TO THE BYZANTINE GENERALS PROBLEM
the network accepts the longer chain !!!
if there are more chains with the same length then the nodes are waiting until
one of the blocks will grow larger than the others and accept that chain
NODES WITH HIGHER HASHING POWER GENERATE LONGER CHAINS
113. Cryptocurrency – 51% Attack
because of the consensus protocol the attacker is able to double spend his coins
„double spending problem”
if the attacker has 51% of the hashing power: it means that he is able to generate the
hashes faster than anyone else in the network
because of the consensus protocol the longest chain is consider to be valid
Algorithm:
1.) keep mining the block BUT keep it private (do not broadcast the mined blocks)
2.) spend you coins in the public network AND do not include these transactions
in your own blockchain
3.) broadcast your blockchain: because you have the highest hashing power
it means you have the longest chain so it will be accepted as the valid chain
4.) the network will accept your blockchain ... you have already spent your coins but
after the broadcast (because of the missing transactions) you can do it again