A shared ledger technology allowing any participant in the business
network to see THE system of record (ledger). Blockchain is a chain of blocks that contains information. The technology behind cryptocurrencies.
This document provides an introduction to blockchain technology. It begins with an analogy of playing a chess game through mail to illustrate how agreeing on a shared transaction history allows distributed parties to agree on the current state. It then discusses how blockchains work by linking transaction records into an immutable chain through cryptographic hashes. This allows distributed parties who don't fully trust each other to reach consensus on the legitimate transaction history without the need for a centralized authority. The document also covers key concepts like validity conditions, proof of work, and how blockchains resolve forks.
The document summarizes the key concepts behind Bitcoin, including:
1) Bitcoin aims to create a peer-to-peer electronic cash system without a central authority by using a public ledger called the blockchain to record all transactions.
2) The blockchain solves the double spending problem by recording every transaction in a block along with a cryptographic proof of work, and the network accepts the longest blockchain as proof of what transactions have been verified.
3) While attackers could theoretically modify past transactions, it would require them to redo the proof of work for all subsequent blocks, which grows impractical as the blockchain lengthens and more nodes confirm additional blocks.
Cryptocurrencies like bitcoin and ether rely on mining as a reward mechanism to incentivize miners to verify transactions. Miners compete to solve complex cryptographic puzzles, with the winner receiving new cryptocurrency as a reward. This mining process underpins the decentralized verification and trust in blockchain networks. While initially used only for financial transactions, ethereum's programmable blockchain enables additional uses like smart contracts and initial coin offerings that have led to growth in cryptocurrencies beyond just bitcoin.
The document provides an introduction to Bitcoin and blockchain technology. It discusses how blockchain creates an immutable and distributed digital ledger through the use of cryptography and consensus across a decentralized network. It notes that while blockchain dates back to the 1970s, it is a novel combination of existing technologies that has created new opportunities for digital currencies, smart contracts, and other applications.
The presentation was given during a session of the Cyber Security Club of BMS College of Engineering.
The slide helps to understand the basics of Cryptocurrency and the various technologies that support it.
Bitcoin is a peer-to-peer electronic cash system that allows for secure, low-inflation transactions without a central authority. It uses public/private key cryptography and a distributed transaction ledger called a blockchain to prevent double spending. Nodes in the Bitcoin network compete to validate transactions by solving computationally difficult proof-of-work puzzles. The longest blockchain held by the majority of nodes represents the valid transaction history and prevents reversal of transactions.
Bitcoin lightning network and ethereum protocolsSUSMIT LAVANIA
These slides explore mechanics Bitcoin Lightning Network as Layer 2 scaling solution in detail . We have also discussed 0x protocol used as recipe for decentralized exchanges and Matic network as scaling solution for ethereum.
This document provides an introduction to blockchain technology. It begins with an analogy of playing a chess game through mail to illustrate how agreeing on a shared transaction history allows distributed parties to agree on the current state. It then discusses how blockchains work by linking transaction records into an immutable chain through cryptographic hashes. This allows distributed parties who don't fully trust each other to reach consensus on the legitimate transaction history without the need for a centralized authority. The document also covers key concepts like validity conditions, proof of work, and how blockchains resolve forks.
The document summarizes the key concepts behind Bitcoin, including:
1) Bitcoin aims to create a peer-to-peer electronic cash system without a central authority by using a public ledger called the blockchain to record all transactions.
2) The blockchain solves the double spending problem by recording every transaction in a block along with a cryptographic proof of work, and the network accepts the longest blockchain as proof of what transactions have been verified.
3) While attackers could theoretically modify past transactions, it would require them to redo the proof of work for all subsequent blocks, which grows impractical as the blockchain lengthens and more nodes confirm additional blocks.
Cryptocurrencies like bitcoin and ether rely on mining as a reward mechanism to incentivize miners to verify transactions. Miners compete to solve complex cryptographic puzzles, with the winner receiving new cryptocurrency as a reward. This mining process underpins the decentralized verification and trust in blockchain networks. While initially used only for financial transactions, ethereum's programmable blockchain enables additional uses like smart contracts and initial coin offerings that have led to growth in cryptocurrencies beyond just bitcoin.
The document provides an introduction to Bitcoin and blockchain technology. It discusses how blockchain creates an immutable and distributed digital ledger through the use of cryptography and consensus across a decentralized network. It notes that while blockchain dates back to the 1970s, it is a novel combination of existing technologies that has created new opportunities for digital currencies, smart contracts, and other applications.
The presentation was given during a session of the Cyber Security Club of BMS College of Engineering.
The slide helps to understand the basics of Cryptocurrency and the various technologies that support it.
Bitcoin is a peer-to-peer electronic cash system that allows for secure, low-inflation transactions without a central authority. It uses public/private key cryptography and a distributed transaction ledger called a blockchain to prevent double spending. Nodes in the Bitcoin network compete to validate transactions by solving computationally difficult proof-of-work puzzles. The longest blockchain held by the majority of nodes represents the valid transaction history and prevents reversal of transactions.
Bitcoin lightning network and ethereum protocolsSUSMIT LAVANIA
These slides explore mechanics Bitcoin Lightning Network as Layer 2 scaling solution in detail . We have also discussed 0x protocol used as recipe for decentralized exchanges and Matic network as scaling solution for ethereum.
Concurrency control is a database concept that addresses conflicts from simultaneous data access or alteration in multi-user systems. It coordinates concurrent transactions while preserving data integrity. For example, without concurrency control, two travelers could purchase the same remaining train ticket. Concurrency control strategies include pessimistic locking, which locks data for the duration it's in memory, and optimistic locking, which detects and resolves collisions when they occur rather than preventing them. Problems can include deadlocks, where processes wait endlessly for each other's resources, and livelocks, where processes constantly change state without progressing. Basic timestamping assigns unique timestamps to transactions and data versions to enable serialization without locks and the possibility of deadlock.
This slidedeck was used at the second Blockchain Vlaanderen meetup in Antwerp. It was given as a general introduction into Blockchain to enable newcomers to follow the presentations that followed.
Introduction into blockchains and cryptocurrenciesSergey Ivliev
Slides from my intro course:
- mapping the digital asset ecosystem (as of August 2019)
- how bitcoin works - step-by-step primer?
- hashrate, dollar value transferred, transaction rate and other metrics (as of August 2019)
- hard money, uncorrelated asset and other use cases
- proof-of-stake and proof-of-identity
- horizontal and vertical scaling
- how ethereum smart contracts work?
- ERC20 token standard
- boom and bust of the ICO market (as of August 2019)
- intro into #DeFI (as of August 2019)
- stablecoins
- MarkerDAO, Compound, Uniswap and other cool decentralized finance protocols
- Cryptokitties, Storj, Peepeth and examples of non-financial dapps
Boolberry improves on existing CryptoNote coins by calculating transaction IDs using only the transaction prefix, excluding ring signatures. This allows ring signatures to be cut off from old transactions, reducing block chain bloat by 55-90% compared to ordinary CryptoNote coins while still proving transactions belong to blocks. Boolberry is designed to be more efficient and provide a more compact, faster synchronizing block chain for a better user experience.
This document provides an overview of cryptocurrencies and Bitcoin. It defines cryptocurrency and describes how Bitcoin works as a decentralized digital currency using cryptography to regulate currency generation and verify fund transfers without a central bank. Key aspects covered include currency vs Bitcoin, Bitcoin expansion, cryptography basics like hashing and digital signatures, blockchain data structures, mining and proof-of-work consensus, and incentives to maintain the Bitcoin network.
The document discusses JSON Web Tokens (JWT), including how they work and how they provide authorization. It explains that JWTs contain encoded JSON objects with a header, payload, and signature. The payload contains claims about the user's identity. JWTs can be used instead of session tokens to authorize API requests since they allow stateless authentication by including all necessary information in the token itself. The document also discusses potential security issues with JWTs and when they are an appropriate authorization mechanism.
Easy-to-understand illustration of the system.
Bitcoin is a virtual currency that can be used on the Internet.
From the name of virtual currency, I'm a little worried, "Isn't the money disappearing in some way?"
The document discusses various concurrency control techniques used in database management systems to ensure transaction isolation. It covers locking techniques like two-phase locking and timestamp ordering. Locking involves associating locks like read/write locks with data items. The two-phase locking protocol defines rules for acquiring and releasing locks in two distinct phases. Timestamp ordering assigns unique timestamps to transactions and ensures conflicting operations are executed based on timestamp order to guarantee serializability.
Can we safely adapt the construction of permissionless blockchain to user dem...I MT
1) The document discusses adapting permissionless blockchain construction to user demand by allowing the number of blocks and block creation rate in a blockchain to self-adapt to transaction demand.
2) It proposes a system called Sycomore that moves from a chain of blocks to a directed acyclic graph (DAG) of blocks where the predecessor of a block is not predictable.
3) Sycomore aims to partition transactions over blocks in a way that is verifiable by anyone and allows the blockchain to scale to thousands of transactions per second while maintaining security properties like preventing double spending.
A Complete Beginners Guide to Blockchain Technology Part 4 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
Talk for CodeMash 2018. Page to end for resources. Some more links (click to expand):
Bitcoin's Insane Energy Consumption Explained: https://arstechnica.com/tech-policy/2017/12/bitcoins-insane-energy-consumption-explained/
The Ethereum-blockchain size will not exceed 1TB anytime soon.
https://dev.to/5chdn/the-ethereum-blockchain-size-will-not-exceed-1tb-anytime-soon-58a
For use rights, please see license agreement below.
A Complete Beginners Guide to Blockchain Technology Part 3 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
A short seminar presentation on the technical background of Bitcoins. Some basic concepts behind bitcoin addresses are discussed. An overview on the concepts of transactions and blocks is given.
Trick or Treat?: Bitcoin for Non-Believers, Cryptocurrencies for CypherpunksDavid Evans
David Evans
DC Area Crypto Day
Johns Hopkins University
30 October 2015
This (non-research) talk will start with a tutorial introduction to cryptocurrencies and how bitcoin works (and doesn’t work) today. We’ll touch on some of the legal, policy, and business aspects of bitcoin and discuss some potential research opportunities in cryptocurrencies.
A Complete Beginners Guide to Blockchain Technology Part 5 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
What is a decentralised application ? - Les Jeudis du LibreWajug
A decentralized application (DApp) is an application that runs on a decentralized network like Ethereum rather than being hosted and controlled by a single company. A DApp uses blockchain technology and smart contracts to allow peer-to-peer transactions and decisions without an intermediary. Ethereum allows developers to create DApps with Turing-complete smart contracts that can automate processes and disintermediate industries like banking, insurance, and more. DApps are accessed through a web interface or mobile app and interact with smart contracts deployed on the Ethereum blockchain.
The document discusses the Lightning Network, which aims to scale bitcoin transactions by enabling instant, low-cost payments through off-chain payment channels. It describes key concepts like payment channels, routing payments across multiple nodes, and implementations. The Lightning Network allows for near-instant micropayments, smart contracts, and cross-chain atomic swaps by using timelocks and hashed timelock contracts to securely transfer bitcoin off the main blockchain.
Sidechains allow the transfer of assets between blockchains through a two-way peg mechanism. This mechanism uses cryptographic proofs to lock assets on one blockchain and unlock equivalent assets on another blockchain. It provides properties like atomic transfers without counterparty risk. There are challenges around complexity, potential for fraudulent transfers through deep reorganizations, and risks of centralization for sidechains with mining. Applications include experimentation with new features on separate blockchains and issuing new blockchain-based assets.
Bitcoin uses a blockchain to prevent double spending in a distributed system. The blockchain is a global ledger that sorts transactions into a linear order. It is very difficult to rewrite a large portion of the blockchain due to the computational power required to solve puzzles needed to add blocks. This makes double spending improbable without controlling over 50% of the network's hashing power. New blocks are added about every 10 minutes through a proof-of-work process where miners solve difficult puzzles to write blocks and receive bitcoins as a reward.
Blockchains allow mutually distrusting entities to agree on a system's state by agreeing on its transaction history. They use cryptographic hash chains, where each record contains the hash of the previous record. This commits all records to the chain, preventing changes. Blockchains add validity conditions and consensus rules to decide which chains are accepted. In permissioned blockchains, trusted entities vote to add blocks. In proof-of-work blockchains like Bitcoin, miners perform computations to add blocks and resolve disputes between chains. While powerful, proof-of-work has costs around efficiency and incentives that permissioned alternatives aim to address. Overall, blockchains coordinate distributed consensus without a central authority.
Bitcoins: Application of blockchain technologyShiv Sahni
Shiv Sahni provides a concise summary of the origins and technical workings of Bitcoin:
- Bitcoin was first conceived in 2007 and the domain bitcoin.org was registered in 2008 by its anonymous creator, Satoshi Nakamoto. The first Bitcoin block, known as the genesis block, was mined on January 3, 2009.
- Bitcoins are recorded on a public ledger called the blockchain. Transactions are grouped into blocks that are linked through cryptography. Miners use specialized hardware to validate transactions and are rewarded with new bitcoins.
- Keys and digital signatures ensure security - users have private keys that sign transactions to prove ownership, while public keys can receive bitcoins. Addresses are generated from public keys through has
Concurrency control is a database concept that addresses conflicts from simultaneous data access or alteration in multi-user systems. It coordinates concurrent transactions while preserving data integrity. For example, without concurrency control, two travelers could purchase the same remaining train ticket. Concurrency control strategies include pessimistic locking, which locks data for the duration it's in memory, and optimistic locking, which detects and resolves collisions when they occur rather than preventing them. Problems can include deadlocks, where processes wait endlessly for each other's resources, and livelocks, where processes constantly change state without progressing. Basic timestamping assigns unique timestamps to transactions and data versions to enable serialization without locks and the possibility of deadlock.
This slidedeck was used at the second Blockchain Vlaanderen meetup in Antwerp. It was given as a general introduction into Blockchain to enable newcomers to follow the presentations that followed.
Introduction into blockchains and cryptocurrenciesSergey Ivliev
Slides from my intro course:
- mapping the digital asset ecosystem (as of August 2019)
- how bitcoin works - step-by-step primer?
- hashrate, dollar value transferred, transaction rate and other metrics (as of August 2019)
- hard money, uncorrelated asset and other use cases
- proof-of-stake and proof-of-identity
- horizontal and vertical scaling
- how ethereum smart contracts work?
- ERC20 token standard
- boom and bust of the ICO market (as of August 2019)
- intro into #DeFI (as of August 2019)
- stablecoins
- MarkerDAO, Compound, Uniswap and other cool decentralized finance protocols
- Cryptokitties, Storj, Peepeth and examples of non-financial dapps
Boolberry improves on existing CryptoNote coins by calculating transaction IDs using only the transaction prefix, excluding ring signatures. This allows ring signatures to be cut off from old transactions, reducing block chain bloat by 55-90% compared to ordinary CryptoNote coins while still proving transactions belong to blocks. Boolberry is designed to be more efficient and provide a more compact, faster synchronizing block chain for a better user experience.
This document provides an overview of cryptocurrencies and Bitcoin. It defines cryptocurrency and describes how Bitcoin works as a decentralized digital currency using cryptography to regulate currency generation and verify fund transfers without a central bank. Key aspects covered include currency vs Bitcoin, Bitcoin expansion, cryptography basics like hashing and digital signatures, blockchain data structures, mining and proof-of-work consensus, and incentives to maintain the Bitcoin network.
The document discusses JSON Web Tokens (JWT), including how they work and how they provide authorization. It explains that JWTs contain encoded JSON objects with a header, payload, and signature. The payload contains claims about the user's identity. JWTs can be used instead of session tokens to authorize API requests since they allow stateless authentication by including all necessary information in the token itself. The document also discusses potential security issues with JWTs and when they are an appropriate authorization mechanism.
Easy-to-understand illustration of the system.
Bitcoin is a virtual currency that can be used on the Internet.
From the name of virtual currency, I'm a little worried, "Isn't the money disappearing in some way?"
The document discusses various concurrency control techniques used in database management systems to ensure transaction isolation. It covers locking techniques like two-phase locking and timestamp ordering. Locking involves associating locks like read/write locks with data items. The two-phase locking protocol defines rules for acquiring and releasing locks in two distinct phases. Timestamp ordering assigns unique timestamps to transactions and ensures conflicting operations are executed based on timestamp order to guarantee serializability.
Can we safely adapt the construction of permissionless blockchain to user dem...I MT
1) The document discusses adapting permissionless blockchain construction to user demand by allowing the number of blocks and block creation rate in a blockchain to self-adapt to transaction demand.
2) It proposes a system called Sycomore that moves from a chain of blocks to a directed acyclic graph (DAG) of blocks where the predecessor of a block is not predictable.
3) Sycomore aims to partition transactions over blocks in a way that is verifiable by anyone and allows the blockchain to scale to thousands of transactions per second while maintaining security properties like preventing double spending.
A Complete Beginners Guide to Blockchain Technology Part 4 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
Talk for CodeMash 2018. Page to end for resources. Some more links (click to expand):
Bitcoin's Insane Energy Consumption Explained: https://arstechnica.com/tech-policy/2017/12/bitcoins-insane-energy-consumption-explained/
The Ethereum-blockchain size will not exceed 1TB anytime soon.
https://dev.to/5chdn/the-ethereum-blockchain-size-will-not-exceed-1tb-anytime-soon-58a
For use rights, please see license agreement below.
A Complete Beginners Guide to Blockchain Technology Part 3 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
A short seminar presentation on the technical background of Bitcoins. Some basic concepts behind bitcoin addresses are discussed. An overview on the concepts of transactions and blocks is given.
Trick or Treat?: Bitcoin for Non-Believers, Cryptocurrencies for CypherpunksDavid Evans
David Evans
DC Area Crypto Day
Johns Hopkins University
30 October 2015
This (non-research) talk will start with a tutorial introduction to cryptocurrencies and how bitcoin works (and doesn’t work) today. We’ll touch on some of the legal, policy, and business aspects of bitcoin and discuss some potential research opportunities in cryptocurrencies.
A Complete Beginners Guide to Blockchain Technology Part 5 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
What is a decentralised application ? - Les Jeudis du LibreWajug
A decentralized application (DApp) is an application that runs on a decentralized network like Ethereum rather than being hosted and controlled by a single company. A DApp uses blockchain technology and smart contracts to allow peer-to-peer transactions and decisions without an intermediary. Ethereum allows developers to create DApps with Turing-complete smart contracts that can automate processes and disintermediate industries like banking, insurance, and more. DApps are accessed through a web interface or mobile app and interact with smart contracts deployed on the Ethereum blockchain.
The document discusses the Lightning Network, which aims to scale bitcoin transactions by enabling instant, low-cost payments through off-chain payment channels. It describes key concepts like payment channels, routing payments across multiple nodes, and implementations. The Lightning Network allows for near-instant micropayments, smart contracts, and cross-chain atomic swaps by using timelocks and hashed timelock contracts to securely transfer bitcoin off the main blockchain.
Sidechains allow the transfer of assets between blockchains through a two-way peg mechanism. This mechanism uses cryptographic proofs to lock assets on one blockchain and unlock equivalent assets on another blockchain. It provides properties like atomic transfers without counterparty risk. There are challenges around complexity, potential for fraudulent transfers through deep reorganizations, and risks of centralization for sidechains with mining. Applications include experimentation with new features on separate blockchains and issuing new blockchain-based assets.
Bitcoin uses a blockchain to prevent double spending in a distributed system. The blockchain is a global ledger that sorts transactions into a linear order. It is very difficult to rewrite a large portion of the blockchain due to the computational power required to solve puzzles needed to add blocks. This makes double spending improbable without controlling over 50% of the network's hashing power. New blocks are added about every 10 minutes through a proof-of-work process where miners solve difficult puzzles to write blocks and receive bitcoins as a reward.
Blockchains allow mutually distrusting entities to agree on a system's state by agreeing on its transaction history. They use cryptographic hash chains, where each record contains the hash of the previous record. This commits all records to the chain, preventing changes. Blockchains add validity conditions and consensus rules to decide which chains are accepted. In permissioned blockchains, trusted entities vote to add blocks. In proof-of-work blockchains like Bitcoin, miners perform computations to add blocks and resolve disputes between chains. While powerful, proof-of-work has costs around efficiency and incentives that permissioned alternatives aim to address. Overall, blockchains coordinate distributed consensus without a central authority.
Bitcoins: Application of blockchain technologyShiv Sahni
Shiv Sahni provides a concise summary of the origins and technical workings of Bitcoin:
- Bitcoin was first conceived in 2007 and the domain bitcoin.org was registered in 2008 by its anonymous creator, Satoshi Nakamoto. The first Bitcoin block, known as the genesis block, was mined on January 3, 2009.
- Bitcoins are recorded on a public ledger called the blockchain. Transactions are grouped into blocks that are linked through cryptography. Miners use specialized hardware to validate transactions and are rewarded with new bitcoins.
- Keys and digital signatures ensure security - users have private keys that sign transactions to prove ownership, while public keys can receive bitcoins. Addresses are generated from public keys through has
The document provides definitions and explanations of key concepts related to blockchain technology and cryptocurrencies like Bitcoin. It discusses how blockchain works as a distributed ledger using cryptography and consensus to allow decentralized transactions without intermediaries. It also addresses common questions around how Bitcoin transactions are validated and added to the blockchain through mining processes.
"How Blockchains and Bitcoins work" by Ricardo Águas @ Pizza Talks Lisbon 201...Equal Experts
This document provides an overview of blockchains and bitcoin. It first explains basic cryptography concepts like symmetric encryption, public key cryptography, and hash functions. It then discusses how blockchains work by linking blocks together through hashes. Blockchains provide security by making alterations to past blocks difficult. Bitcoin uses public key cryptography and blockchains to allow digital value transfers without a central authority. Transactions are ordered through a mining process where miners compete to validate blocks and earn rewards.
What is a blockchain?
Why is cryptocurrency the future?
It's a deck I was preparing for a lighting talk at ESGgo.
Since I got some excellent feedback on it - I decided to open-source it :)
Hopefully, you will find it valuable.
A brief introduction to Blockchain and the underlying technology of distributed computing, challenges and future scope.
Copyrights belong to the respective owners, intention is purely for informational/educational purpose
I would like to thank various blogs, technical tutorials, books, videos to help me understand the basics and collate this presentaion
The document provides an overview of cryptocurrencies and digital currencies. It discusses why crypto is important for information security, IP protection, and protection against ransomware. It then outlines a plan to cover Bitcoin and its history, characters, mechanisms, blockchain, symmetric and asymmetric crypto algorithms, breaking crypto difficulties, and comparisons to other digital currencies like Litecoin. Practical exercises on wallets, transfers, and exchanges are also mentioned. Additional advanced topics like SegWit, zero-knowledge proofs, and homomorphic encryption are included as bonuses.
This document summarizes a talk on blockchain technology for developers. It discusses key concepts like digital signatures, cryptographic hash functions, Merkle trees, distributed consensus, and different failure models. It then covers the use of blockchains for applications like e-cash and titles. Specific blockchain protocols like Bitcoin and Ethereum are examined, looking at transactions, scripting, and addressing schemes. Scalability, off-chain solutions, and alternative consensus mechanisms are also addressed. The talk concludes with advice around building on existing frameworks rather than designing one's own crypto or blockchain from scratch.
Blockchain is a way of storing data in a way that makes it immutable and prevents tampering. It works by storing data in blocks that are chained together using cryptography. Each block contains a cryptographic hash of the previous block, linking the blocks together. This makes it very difficult to tamper with past data, as any change would require recalculating all subsequent hashes. Blockchains use a peer-to-peer network where each node maintains a copy of the chain. When a new block is created, it is distributed across the network and nodes must reach consensus on its validity before it is added to the chain. This process of proof-of-work secures the blockchain and distributed ledger.
This document provides an introduction to blockchain technology. It defines blockchain as a distributed database of records stored in immutable blocks connected with prior blocks forming a chain, where the validity is affirmed by peers in a decentralized network secured by cryptography. It discusses key aspects of blockchain including decentralization, transparency, immutability, consensus mechanisms, and applications such as financial transactions, digital identity, and peer-to-peer networks. Permissioned blockchains are also covered as a way to allow distributed transparency and immutability while controlling access. Regulatory compliance is noted as an important consideration for blockchain implementations.
This document provides an overview of blockchain and Bitcoin concepts, and how they can be implemented and extended using Scala. It begins by discussing different perspectives on what blockchain is and its significance. It then dives into Bitcoin, explaining its use of cryptography, immutable data structures, and proof-of-work to encode decentralized trust. The document discusses Bitcoin's transaction and UTXO data model. It also introduces the Scorex framework for building blockchains in Scala and shows how it implements and generalizes Bitcoin concepts. Finally, it briefly mentions some other Scala-based cryptocurrency and blockchain projects.
TBBUG - Deep Dive (Part 1) - 2022Nov29.pdfParesh Yadav
This document provides an overview and introduction to key concepts in the current blockchain ecosystem. It discusses perspectives on what blockchains are, including as immutable distributed ledgers, trustless systems, and multi-party accounting systems. It also outlines what blockchains can do, such as powering coins, tokens, smart contracts for applications like DeFi, and limitations around scaling. The document discusses consensus mechanisms, public vs private blockchains, and challenges around oracles. It recommends a focus on core concepts, secure coding, and ignoring hype around prices and events when working with blockchain technology.
The Stellar Blockchain and The Story of the Federated Consensus — Blockchain ...Ory Band
We'll dive deeper into the Federated consensus networks, focusing on Stellar and Ripple,
and discuss how they differ from other popular decentralized consensus solutions such as Proof-of-Work and Proof-of-Stake.
We'll assess their pros and cons, and discuss the business requirements that drive companies to adopt these solutions over others.
Video of the presentation is available here: https://www.youtube.com/watch?v=QSpG6a9bmu0
Related blog post in Blockchain Academy TLV: https://medium.com/kinblog/the-stellar-blockchain-and-the-story-of-the-federated-consensus-blockchain-academy-f332eaadefc1
Blockchain has gained lots of attention in recent years. Bitcoin and Ethereum are leading the race. Crypto currencies in spite of uncertainty and volatility are here to stay. Smart contract programming is the future for the Internet 3.0.
Blockchain is a decentralized and distributed database where information is stored in blocks that are linked together in a chain. Transactions on the blockchain are verified by miners and added to the chain, where they cannot be altered. This allows blockchain to enable trustless transactions without centralized authorities. Smart contracts are programs stored on the blockchain that automatically execute transactions according to predetermined rules, allowing for applications like betting systems and supply chain management. Ethereum is a blockchain platform that runs smart contracts, allowing developers to write programs that control transactions and assets on the blockchain.
Learn the fundamentals of blockchain technology and the properties of a blockchain that make it ideal for securing information including financial transactions. We also go into some details of the operation of the Bitcoin protocol as the first real-world example of a successful implementation of blockchain principles. You will come away with an excellent foundation for understanding any Proof of Work based blockchain and an ability to independently evaluate any new blockchain based technology.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Things to Consider When Choosing a Website Developer for your Website | FODUUFODUU
Choosing the right website developer is crucial for your business. This article covers essential factors to consider, including experience, portfolio, technical skills, communication, pricing, reputation & reviews, cost and budget considerations and post-launch support. Make an informed decision to ensure your website meets your business goals.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Fueling AI with Great Data with Airbyte WebinarZilliz
This talk will focus on how to collect data from a variety of sources, leveraging this data for RAG and other GenAI use cases, and finally charting your course to productionalization.
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
2. Agenda
● What is Blockchain Technology
● How does it work
● Building blocks for Blockchain
● Application of Blockchain
● Summary
● References
3. Warm-up: Alice and Bob want to play chess by mail
● Alice sends Bob “1 e4”
● Bob sends back “1 ... e5”
● Alice sends Bob “2 Nf3”
● ...
● Each of these messages is one move in the game
● What’s necessary for them to be able to play the game?
4. They have to agree on the state of the board
If they don’t agree on the state of the board, they can’t play a game!
1. Both know the starting positions of the board.
2. Both know the sequence of messages so far.
a. Those messages make up a transcript of the game.
3. Thus, they can reconstruct the state of the board.
If we agree on history, we agree on the present state of the world!
5. Blockchain
● A shared ledger technology allowing any participant in the business
network to see THE system of record (ledger)
● Blockchain is a chain of blocks that contains information
● The technology behind cryptocurrencies.
6. What’s that got to do with blockchain?
● We have some distributed system
● We need to all agree on the state of some system
● We all agree on the initial state of the system
● A blockchain contains a history of individual transactions
● Thus: We can all agree on the current state of the system
A blockchain lets mutually-distrusting entities agree on history...
...which lets them agree on the state of the system now.
7. Why is this important?
● Example: Bitcoin
● Suppose I want to transfer 100 BTC to you.
● You need to know whether my account has 100 BTC in it.
● For that, you need to know the current state of the system.
● Note: You need to know the current state
○ If you’re looking at an old state of the system, I might be paying you with money I’ve
already spent!
8. What problem does a blockchain solve?
A blockchain lets us agree on the state of the system, even if we don’t all trust
each other!
● Ultimate goal: We all need to agree on the state of some system.
○ How much BTC in each account?
○ Who owns which property?
○ What’s the current state of my program?
● We can all agree on that if we agree on history.
○ Starting state + history -> current state
● We don’t want a single trusted arbiter of the state of the world.
○ We want some level of decentralization—not a single point of failure or compromise.
9. Trusted Arbiter
● If we had a completely trusted arbiter, we wouldn’t need a blockchain!
● We could just define reality as whatever TA said it was.
● For a payment system, imagine TA as the bank
○ Bank provides the official sequence of transactions and account balances
○ When you want to spend your money, you send a message to bank
○ Bank permits transaction if you have money, and updates account balances.
10. Why not just have a trusted arbiter, then?
1. Single point of failure
a. If the TA goes down for a week, the system stops working!
b. If TA gets compromised, whole system will be compromised
2. Concentration of power
a. “He who controls the past, controls the future”
b. TA can censor transactions, impose new conditions to get transactions included in history,
etc.
3. Maybe there’s nobody we all trust
11. Blockchain
● Distributed system
● We don’t all trust each other or any single entity
● We want to agree on history
● ...so we can agree on the state of our system...
● ...so we can do something.
We get the functionality of a trusted arbiter...
...without needing a trusted arbiter
12. How does it work?
● A blockchain is a sequence of hash-chained records
○ Once you’ve seen record N, you can’t change anything in the past.
● Some procedure for adding blocks to blockchain
○ Who gets to add blocks? How is it done?
● Validity conditions for new blocks
○ Are transactions valid? Are digital signatures correct? Etc.
○ Enforced by consensus-–chains with invalid blocks won’t be accepted.
● Some procedure for deciding between alternative candidate blockchains.
○ When Alice and Bob have different pictures of history, there’s some way for them to
eventually come to agreement about who is right.
13. Building Block: Cryptographic hash functions
A cryptographic hash function:
● Takes any bitstring as an input (Like a 10 MB file)
● Produces a fixed-length output (Typically 256 or 512 bits)
● Nobody can find collisions.
● Examples: SHA256, SHA512, SHA3-256, RIPEMD-160
14. What’s a collision?
● Suppose I can find two different inputs X and Y so that
Hash(X) = Hash(Y)
● That’s a collision.
● For a cryptographic hash function to be any good, it needs to be
collision-resistant.
● That just means it’s impossible in practice to find colliding inputs.
15. Why is collision resistance useful?
● If nobody can find X != Y such that Hash(X) == Hash(Y),
● ...then we can use hash(X) as a kind of message digest of X.
○ Digital signatures actually sign hash(message) instead of message.
● Nobody can change X without changing hash(X)
○ If they could do that, they can find collisions for hash()
● hash(X) also commits to X.
○ Once I’ve seen hash(X), later, you can show me X, and I’ll know it’s the value you
committed to
○ ...you can’t show me some other X*, because it won’t have the same hash.
16. Building block: Hash chains
● A hash chain is a sequence of records in which each record contains the
hash of the previous record in the chain, and the hash of all the current
record’s contents.
17. How does it secure the chain
● We’re using a cryptographic hash function like SHA256.
● That means nobody can find two inputs with the same hash value.
● ...and that means that record N contains a commitment to record N-1
● ...which contains a commitment to record N-2, which contains a
commitment to record N-3, and so on.
19. Hash chains and blockchains
● Hash chains have the property that every record contains a
commitment to all previous records.
○ If you change record N, this changes the final hashes of records N+1, N+2, ...
● Result: Once we all accept record N, we have locked in the contents of
record 1, 2, 3, ..., N-1 as well.
● Blockchains use hash chains as a component
● Hash chains are also useful in a lot of other contexts
○ For example, a system with a trusted arbiter can use a hash chain to limit the arbiter’s
power—even the arbiter can’t change history.
20. The blockchain
● Each block in the chain commits to all previous blocks and transactions
21. Building Block: Validity conditions
What will the world accept as the next block?
● We don’t have some trusted entity to decide what may be added to
blockchain
● ...so we have to decide what blocks are valid.
● Example: Bitcoin
○ Signatures needed for moving BTC from an account
○ Not allowed to leave a negative balance in an account
○ Block must contain correct proof-of-work
● A proposed additional block that doesn’t meet these conditions won’t be
accepted by the rest of the network.
Enforced by consensus
22. Adding new blocks to the chain
● Any blockchain system has to determine who can add new blocks to the
chain, and how it’s done.
● Two main ideas which are most popular
○ Proof of work
○ Permissioned blockchain
● Also more ideas
○ Proof of stake
○ Proof of storage
○ Probably several more
23. Building Block: Proof of Work
● I want you to do a big computation.
○ I want you to prove you did it.
○ I don't want to do much work checking the proof.
● Why is this useful?
○ Limits the rate of new blocks
○ Makes attempts to add invalid blocks to the chain expensive
○ Provides a clear way to decide between competing chains when there is a
disagreement—the one with the most work wins.
Note: Not all blockchains use proof of work
24. Hash-based proof of work
● I give you challenge C and limit L = 2220
.
● Ask you to find N such that
SHA256(C||N) < L
● Expected work = 236
● Each new N has prob 2-36
of success
● When you succeed, only takes me one hash to check.
26. Proofs of work solve some problems...
● We can resolve disagreements.
○ When chain forks, take fork with most work.
○ When there’s a tie, keep working till one of the chains has the most work.
● Discourage people trying to add invalid blocks to chain.
○ You spend money adding a block to chain...
○ ...but if it’s not valid, nobody accepts it.
● Part of how Bitcoin’s very clever design of incentives works.
27. ...but has some constraints
● Expensive—lots of energy used to generate proofs
○ Done by “miners” in Bitcoin
○ Use special-purpose mining rigs optimized for doing proofs of work.
○ Environmental impact—uses lots of power, accomplishing no useful goal except keeping
blockchain working
● Slow—proof of work seems to put a limit on transaction speed
○ Even more when you consider need to resolve potential disagreements
○ Bitcoin rule of thumb is wait 6 blocks (about an hour) to be sure of transaction
28. Permissioned blockchains
● An alternative to proof-of-work
● We have set of somewhat-trusted entities who can work together to add
records to the blockchain.
● For example, we could have five trustees, and if any 3/5 vote in favor of
accepting a block on the chain, then the block is added.
● Validity condition for adding a block = 3/5 signatures
● Resolution for conflicting chains = look for longest chain
○ With 3/5 there shouldn’t be any forked chains—someone would have to vote for two
competing blocks!
29. Incentive design
● The real genius in Bitcoin’s design is the way incentives are aligned
○ Untrusted, self-interested miners keep the system working
○ They have a big incentive to follow the protocol
○ They have substantial capital invested in Bitcoin, so they also have an incentive to avoid
any attack that would undermine their investment
○ This all works because Bitcoin is all about moving money around, so it’s easy to build
payoffs into the protocol.
● Other blockchains (especially permissioned ones) have to find alternatives
to incentives
○ Not so obvious how to build a payoff into a protocol to store medical records
30. Application
● Proofs of work
○ Bitcoin and other cryptocurrencies
● Permissioned blockchain
○ Intra-bank settlement
○ Retail banking
■ Cross border remittance
■ Mortgage verification
■ Mortgage contracts (smart contract)
○ Public records
■ Real estate records
■ Vehicle registrations
■ Business license and ownerships records
32. Summary : Blockchains let us agree on history
● We don’t have to trust each other
● We don’t have to have a trusted third party
● System is distributed
● Agreeing on history -> agreeing on state of system
● The Nth record in the hash chain commits to all previous records.
● Can’t change any previous record without making hash chain invalid.
33. Summary : Permissioned vs Proof-of-work
● Most blockchains in use now use proof-of-work
● Many new proposals use permissioned blockchains
○ Some set of somewhat-trusted entities
● There are other ways to do it
○ Proof of storage
○ Proof of stake
○ ...
34. References:
1. Satoshi Nakamoto, “Bitcoin: A Peer-to-Peer Electronic Cash System”
https://bitcoin.org/bitcoin.pdf, 2008.
2. Ferdinando M. Ametrano, “Bitcoin and Blockchain Technology”,
https://www.slideshare.net/Ferdinando1970, 2016.
3. John Kelsey, “Introduction to Blockchains”.
4. A. Shanti Bruyn, “Blockchain an introduction”,
https://beta.vu.nl/nl/Images/werkstuk-bruyn_tcm235-862258.pdf, 2017.
5. IBM Corporation, “Making Blockchain Real for Business Explained 1 V2.09
19 Jan 16”, https://ibm.box.com/BlockExp.