Blockchain is a distributed public ledger that records all Bitcoin transactions in a permanent, verifiable way. It uses cryptography to ensure the integrity and security of each transaction. New transactions are grouped into blocks and added to the blockchain through a process called mining, where miners compete to solve complex math problems. In return for securing the network, miners are rewarded with new Bitcoins. This decentralized system allows for peer-to-peer transactions without an intermediary.
Hands-on introduction to blockchain technologies.
First, basic concepts as peer-to-peer networks, mining and distributed consens are introduced basd on the Bitcoin protocol. Next smart contracts are discussed for the Ethereum protocol and demonstrated using a local/private blockchain.
The session concludes with a live demo of the interaction of a Java based classical business application with a smart contract running in the Ethereum network.
The goal of the session is to provide a meaningful background of blockchain technologies in genral and to enable developers to start exploring Ethereum and smart contracts within a few hours.
The proposed development setup is oriented towards Java developers and contains Docker images for the Geth and TestRPC Ethereum clients that can be run locally. To access Ethereum from Java the web3j Java library is used. The business application that integrates with the smart contracts is built with the Eclipse Scout framework.
Slides have been created by @ZimMatthias for the JUG Switzerland session on May 22, 2017 https://www.jug.ch/html/events/2017/blockchain_ethereum.html
Virtual or digital currencies, with Bitcoin chief amongst them, have been gaining momentum and investment over the last couple of years. Offering an almost costless means of making payments around the globe, virtual currencies have the potential to bring significant disruption to the banking industry. This potential is not lost on either Bitcoin startups or banks themselves. But how does Bitcoin actually work? A peer-to-peer network maintains the “blockchain”, an innovative cryptographic protocol which securely mediates payments between parties without mutual trust. This session will step through the structure of the blockchain, showing how it solves the “double spend” problem and allows decentralised processing of financial transactions. Whether Bitcoin will become the currency of the internet or it’s a bubble that is doomed to burst sooner or later, the blockchain itself will change the face of transactional banking and perhaps other industries along the way.
Presentation to the Sydney Financial Mathematics Workshop (11 March 2015)
http://www.qgroup.org.au/content/bitcoin-banking-and-blockchain
An introductory look at various Blockchain Technologies and examples. In this slide I explain about basics of Etherium and types of Blockchain technology currently present and some known public projects/examples which use Blockchain.
There are new and emerging opportunities for organisations in all sectors to create and deliver compelling services for their customers using the power of disruptive innovation. As organisations formulate their plans for the coming months, this paper aims to help business and public sector leaders understand the cultural and organisational challenges that are inevitably brought by the use of blockchain technologies, and provides them with the insights they need to overcome them.
Hands-on introduction to blockchain technologies.
First, basic concepts as peer-to-peer networks, mining and distributed consens are introduced basd on the Bitcoin protocol. Next smart contracts are discussed for the Ethereum protocol and demonstrated using a local/private blockchain.
The session concludes with a live demo of the interaction of a Java based classical business application with a smart contract running in the Ethereum network.
The goal of the session is to provide a meaningful background of blockchain technologies in genral and to enable developers to start exploring Ethereum and smart contracts within a few hours.
The proposed development setup is oriented towards Java developers and contains Docker images for the Geth and TestRPC Ethereum clients that can be run locally. To access Ethereum from Java the web3j Java library is used. The business application that integrates with the smart contracts is built with the Eclipse Scout framework.
Slides have been created by @ZimMatthias for the JUG Switzerland session on May 22, 2017 https://www.jug.ch/html/events/2017/blockchain_ethereum.html
Virtual or digital currencies, with Bitcoin chief amongst them, have been gaining momentum and investment over the last couple of years. Offering an almost costless means of making payments around the globe, virtual currencies have the potential to bring significant disruption to the banking industry. This potential is not lost on either Bitcoin startups or banks themselves. But how does Bitcoin actually work? A peer-to-peer network maintains the “blockchain”, an innovative cryptographic protocol which securely mediates payments between parties without mutual trust. This session will step through the structure of the blockchain, showing how it solves the “double spend” problem and allows decentralised processing of financial transactions. Whether Bitcoin will become the currency of the internet or it’s a bubble that is doomed to burst sooner or later, the blockchain itself will change the face of transactional banking and perhaps other industries along the way.
Presentation to the Sydney Financial Mathematics Workshop (11 March 2015)
http://www.qgroup.org.au/content/bitcoin-banking-and-blockchain
An introductory look at various Blockchain Technologies and examples. In this slide I explain about basics of Etherium and types of Blockchain technology currently present and some known public projects/examples which use Blockchain.
There are new and emerging opportunities for organisations in all sectors to create and deliver compelling services for their customers using the power of disruptive innovation. As organisations formulate their plans for the coming months, this paper aims to help business and public sector leaders understand the cultural and organisational challenges that are inevitably brought by the use of blockchain technologies, and provides them with the insights they need to overcome them.
Bitcoin and blockchain are not the same things, although they are related in that blockchain technology was first described and implemented in Bitcoin. Learn More about Blockchain:
Content that helps to understand bitcoin and blockchain. Starts with currency basics, to clear the fact that bitcoin is not doing anything tangentially wrong. Followed by that bitcoin is covered and blockchain in detail.
Blockchain overview, use cases, implementations and challengesSébastien Tandel
Most know about Bitcoin, the well-known crypto-currency. Less know the details about the underlying and enabling technology, Blockchain.
Hopefully, this presentation provides enough insights to understand blockchain concepts and why it's perceived to potentially disrupt many market segments, from retail to governments, from finance to health care. At last, I hope to brush fairly the many challenges of this rather new technology.
What is a Cryptocurrency?
What is the Blockchain?
Why the Blockchain now?
Lets Sum this Blockchain!
Why the “Blockchain” is next IT revolution you have not heard of..
Lets talk about Careers in the Blockchain!
Blockchain workshop PwC March 2018. Explanation of bitcoin and blockchain, Historical analogies, pros and cons, examlples. (Slides don't tell the full story, it included hands on activtiies)
Blockchain concept and technology. How this is becoming the next trend after the Bitcoin, expanding to a myriad of solutions. Smart contracts might be using a public distributed, and encrypted platform to support data persistence.
The new digital era is knocking our doors, and these are arguably the most exciting times post invention of internet itself. Open your doors to the new advanced digital world, which promises to simplify and automate a lot of things around. In the list of remarkable technologies that promise to change the world, is Blockchain.
Conceived in 2008, this concept is generating a lot of buzz. This presentation discusses about this technology, working mechanism in case of Bitcoin, and its use cases beyond crypto-curreinces.
Grokking TechTalk #17: Introduction to blockchainGrokking VN
Speaker: Do The Luan - CARDADO labo
Bio: I work currently for CARDADOlabo, a Japanese Fintech startup. I'm obsessed by Ethereum and I have had a strong passion of research. I hold B.S from University of Science of HCM city and a M.S of computer science from La Rochelle University. I was a lecturer for 3 years at the University of Information Technology.
Description:
In this talk, Luan will share with us a high-level technical introduction about Blockchain, Bitcoin and Eutherium.
- What is blockchain and how is it related to bitcoin?
- What is Ethereum, the second-generation of blockchain
By allowing digital information to be distributed but not copied, blockchain technology created the backbone of a new type of internet. Originally devised for the digital currency, Bitcoin, the tech community is now finding other potential uses for the Blockchain technology.
Ethereum, 2nd generation blockchain technology, is an open source blockchain project that was built specifically to realize the coding of simple contracts on distributed ledgers. Still in its early stages, Ethereum has the potential to leverage the usefulness of blockchain on a truly worldchanging scale.
I am sending you 1π! Pi is a new digital currency developed by Stanford PhDs, with over 9 million members worldwide. To claim your Pi, follow this link https://minepi.com/krishvikram and use my username (krishvikram) as your invitation code.
Step 1. Install the Pi app with above link
Step 2 verify the profile
Step 3 tap on earnings and share your link and increase your earnings
Step 4 verification type the referral code which is mandatory.
Referral code is : krishvikram
This is a presentation is an introduction to the blockchain. It defines, what is the blockchain and shows how JavaScript developers can create blockchain applications.
Bitcoin and blockchain are not the same things, although they are related in that blockchain technology was first described and implemented in Bitcoin. Learn More about Blockchain:
Content that helps to understand bitcoin and blockchain. Starts with currency basics, to clear the fact that bitcoin is not doing anything tangentially wrong. Followed by that bitcoin is covered and blockchain in detail.
Blockchain overview, use cases, implementations and challengesSébastien Tandel
Most know about Bitcoin, the well-known crypto-currency. Less know the details about the underlying and enabling technology, Blockchain.
Hopefully, this presentation provides enough insights to understand blockchain concepts and why it's perceived to potentially disrupt many market segments, from retail to governments, from finance to health care. At last, I hope to brush fairly the many challenges of this rather new technology.
What is a Cryptocurrency?
What is the Blockchain?
Why the Blockchain now?
Lets Sum this Blockchain!
Why the “Blockchain” is next IT revolution you have not heard of..
Lets talk about Careers in the Blockchain!
Blockchain workshop PwC March 2018. Explanation of bitcoin and blockchain, Historical analogies, pros and cons, examlples. (Slides don't tell the full story, it included hands on activtiies)
Blockchain concept and technology. How this is becoming the next trend after the Bitcoin, expanding to a myriad of solutions. Smart contracts might be using a public distributed, and encrypted platform to support data persistence.
The new digital era is knocking our doors, and these are arguably the most exciting times post invention of internet itself. Open your doors to the new advanced digital world, which promises to simplify and automate a lot of things around. In the list of remarkable technologies that promise to change the world, is Blockchain.
Conceived in 2008, this concept is generating a lot of buzz. This presentation discusses about this technology, working mechanism in case of Bitcoin, and its use cases beyond crypto-curreinces.
Grokking TechTalk #17: Introduction to blockchainGrokking VN
Speaker: Do The Luan - CARDADO labo
Bio: I work currently for CARDADOlabo, a Japanese Fintech startup. I'm obsessed by Ethereum and I have had a strong passion of research. I hold B.S from University of Science of HCM city and a M.S of computer science from La Rochelle University. I was a lecturer for 3 years at the University of Information Technology.
Description:
In this talk, Luan will share with us a high-level technical introduction about Blockchain, Bitcoin and Eutherium.
- What is blockchain and how is it related to bitcoin?
- What is Ethereum, the second-generation of blockchain
By allowing digital information to be distributed but not copied, blockchain technology created the backbone of a new type of internet. Originally devised for the digital currency, Bitcoin, the tech community is now finding other potential uses for the Blockchain technology.
Ethereum, 2nd generation blockchain technology, is an open source blockchain project that was built specifically to realize the coding of simple contracts on distributed ledgers. Still in its early stages, Ethereum has the potential to leverage the usefulness of blockchain on a truly worldchanging scale.
I am sending you 1π! Pi is a new digital currency developed by Stanford PhDs, with over 9 million members worldwide. To claim your Pi, follow this link https://minepi.com/krishvikram and use my username (krishvikram) as your invitation code.
Step 1. Install the Pi app with above link
Step 2 verify the profile
Step 3 tap on earnings and share your link and increase your earnings
Step 4 verification type the referral code which is mandatory.
Referral code is : krishvikram
This is a presentation is an introduction to the blockchain. It defines, what is the blockchain and shows how JavaScript developers can create blockchain applications.
Null Mumbai 14th May Lesser Known Webapp attacks by Ninad Sarangnullowaspmumbai
Agenda
We will cover lesser known web application attacks with there basics, how to do and mitigations.
Cross site scripting –
* Mutation XSS
* RPO XSS
* Zombie XSS
Remote Command Execution
CR-LF Attack
Homograph Attack
Blockchain: The Information Technology of the FutureMelanie Swan
The blockchain concept may be one of the most transformative ideas to impact the world since the Internet. Cryptocurrencies like bitcoin are merely one application of the blockchain concept. The blockchain is a public transaction ledger built in a decentralized network structure based on cryptographic principles so that any kind of trading, buying and selling of assets does not need to go through a centralized intermediary. Any kind of asset may be encoded into the blockchain and transacted, validated, or preserved in a much more efficient manner than at present including ideas, health data, financial assets, automobiles, and government documents. Venture Capitalists are calling the blockchain the next big investment wave.
Technology tipping points Big Data and Blockchain use case presentationVinod Kumar Nerella
In this presentation, I am talking about the two technology tipping points big data and Blockchain.
In big data area, the presentation covers use cases in retails, financial and manufacturing sector.
Block chain and its main concepts are explained with the use case smart contracts is introduction and Blockchain can help manufacturing firms for efficient operations.
BlockChains are a logical next step beyond centralised and distributed (networked) ledgers used to record all forms of transaction, files and documentation for legal, medical, industrial, government and defence entities. The biggest change is the lack of any middle man and/or institutions. With open and available to anyone, individuals and groups as well as companies can build open, closed, public or private BlockChains.
The technology constitutes a step function in security, privacy, reliability and utility. Although it is the basis of BitCoin and other currencies, it is not limited to financial transactions and can be applied to all forms of asset movement, agreements, documents, files, voting and more across all sectors.
The base concepts are founded on networking and distributed adjudication processes that generally embrace Digital Signatures, Public and Private Key, Encryption, and Hash Checks.
How the hell do I run my microservices in production, and will it scale?Cloud 66
Let’s assume you’ve already had every *Docker 101 tutorial* for breakfast. You’re now ready to take that brilliantly crafted application into production. But wait… first you need to test your container-based microservices architecture. What does the whole DevOps workflow look like? What about performance and security? And last but not least; how the hell do I run my microservices in production, and will it scale?
Let Daniël guide you through the wonderful world of container-based development and running microservice architectures at scale. By attending the talk, you’ll gain insight into how to bootstrap and dive straight into learning what DevOps workflow should look like when using containers.
Brief description on Blockchain, new kid on the block for FinTech. Diving in deep to ensure layman can understand the inside out of technology. Presented at CSI IT 2020 Conference, Mumbai on 14th Oct 2016
Null 11 june_Malware CNC: Advance Evasion techniques_by Avkash k and dhawal shahnullowaspmumbai
Malware Command and Control: Evasion Tactics and Techniques
Malware is designed to perform malicious actions without catching attention of the user. Malware Authors keep on developing new ideas to stay undetected by security technologies. In order to remain undetected, communication channels between attacker and malware needs to be stealthy and evolving. Making Command and control with attacker to receive on demand commands is an essential phase of the Cyber Kill Chain.
As a result, we are observing continuous advancement into communication channel for Malware Command and control.
In this session, we will try to cover some of the advanced techniques used by Malwares nowadays to communicate with it's command and control.
Burp Suite is a Java based software platform of tools for performing security testing of web applications. The suite of products can be used to combine automated and manual testing techniques and consists of a number of different tools, such as a proxy server, a web spider, scanner, intruder, repeater, sequencer, decoder, collaborator and extender.
Short presentation about bitcoin in particular and crypto currencies in general.
Its mainly a description of whats money and what is bitcoin
why bitcoin will dominate
Everything you ever needed to know about the bitcoin system all explained in baby language, from how it works to how to get started with creating an account, funding an account setting up mining, creating a secure wallet, e.t.c
Sunstone Capital, Avalanche 2014 - Bitcoin: Primer, State of Play, DiscussionYacine Ghalim
Every winter, Sunstone hosts an offsite event with the participation of executives from our portfolio companies, fellow VCs, and various thought leaders.
The event is designed to mix informal networking, stimulating discussions around key topics shaping our industry, and intense skiing. We find that the best inspiration and ideas are generated when you least expect it, and in company with people that challenge your thinking.
This year's edition took us to Courmayeur in the Italian Alps, and Bitcoin was on the list of topics we discussed. Here are the supporting slides from our Jan 24th presentation "Bitcoin: Primer, State of Play, Discussion".
http://www.sunstone.eu
Confused by some of the terms used on CoinDesk? Here you will find a complete bitcoin 101 that will help you to understand digital currency by explaining commonly used terms and their meanings.
Report on Bitcoin- The cryptocurrency (November 2017)AJSH & Co LLP
•What is a Bitcoin?
•Understanding the basics
•How a blockchain works
•Bitcoin- Good or Bad?
•How to obtain a Bitcoin?
•Acceptability of Bitcoin around the world
•Other Cryptocurrencies
•Investing in Bitcoin
This report discuss about Bitcoin and cryptocurrencies - Understanding, Acceptability and Risks
AJSH & Co. have tremendous experience in the field of chartered accounting and have worked with chartered accounting giants in India and abroad. Please feel free to email our team at E: ankit@ajsh.in , siddhartha@ajsh.in also reachable on Direct numbers +91-98106 61322, +91-9811325395. For more information visit our website:- http://www.ajsh.in .
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
2. Index
What is TRANSACTION ?
BlockChain !!!……Never heard what is that??
The BTC Aka BitCoins
Who discovered?
How it works?
Advantages & Disadvantages
Applications
3. hello!
I am Ninad Sarang
Cyber Security Consultant @ NSEIT
You can find me @linkedin >ninad sarang
6. Advantages
Regulated
Controlled & created by government
Hard to steal by hackers
Hard to transmit
Hard to trace
Refundable
Traditional ways of transaction
Disadvantages
No record when coverted to cash
Used for crime
Transaction cycle takes time
Refund process takes time
Fees , charges are applicable
Dependent on trusted third parties
8. ““The first generation of the digital revolution
brought us the Internet of information. The
second generation — powered by blockchain
technology — is bringing us the Internet of value: a
new platform to reshape the world of business
and transform the old order of human affairs for
the better.”
-Don Tapscott
9. the block chain is a public ledger with all Bitcoin transactions that have ever taken place
since the very first one, the so-called Genesis Block. Every active node in the Bitcoin
network has a copy of the block chain. And every time a new “block” is discovered via
mining, it is appended to the block chain, as the name suggests. In other words, the block
chain is a big list of Bitcoin transactions.
The blockchain has complete information about the addresses and their balances right
from the genesis block to the most recently completed block.
Lets Define BlockChain
10. BTC Aka BitCoins
“Lets Understand Blockchain with BTC”
What is Bitcoin?
✘ A protocol that supports a decentralized, pseudo-anonymous, peer-to-peer digital
currency/crypto currency
✘ A publicly disclosed linked ledger of transactions stored in a blockchain
✘ A reward driven system for achieving consensus (mining) based on “Proofs of Work” for
helping to secure the network
✘ A “scare token” economy with an eventual cap of about 21M bitcoins
11. Who Discovered??
“Satoshi Nakamoto” created the reference implementation that began with a Genesis Block of 50
coins.The software is open source and royalty free
2008
✘ August 18 Domain name "bitcoin.org" registered[1].
✘ October 31 Bitcoin design paper published
✘ November 09 Bitcoin project registered at SourceForge.net
2009
✘ January 3 Genesis block established at 18:15:05 GMT
✘ January 9 Bitcoin v0.1 released and announced on the cryptography mailing list
✘ January 12 First Bitcoin transaction, in block 170 from Satoshi to Hal Finney
[1] https://en.bitcoin.it/wiki/History
12. The Basic Mechanism
Transactions are published to the Bitcoin P2P network
Miners (computers) compete to solve a proof-of-work problem on average every 10
minutes
The winning miner publishes a summary of recent transactions in a block
Miners are rewarded with new coins for having published a valid block
Blocks are linked to previous blocks, creating a block chain
The value of every account is evident on the blockchain
Everyone is expected to know the whole blockchain
13. How it works?
Coins flow from Inputs to
Outputs
✘ A coin owner transfers coins by
digitally signing (via ECDSA) a
hash digest of the previous
transaction and the public key
of the next owner. This
signature is then appended to
the end of the coin.
14. Pseudo Anonymous
✘ Using public key cryptography, specifically Elliptic Curve Cryptography due to its
key strength and shorter keys
✘ Transactions are sent to public key “addresses”
1AjYPi8qryPCJu6xgdJuQzVnWFXLmxq9s3
1Give4dbry2pyJihnpqV6Urq2SGEhpz3K
15. Public Ledger
✘ Every viable transaction is stored in a public ledger
✘ Transactions are placed in blocks, which are linked by SHA256 hashes.
https://blockchain.info
16. Arriving at Consensus
✘The longest path represents the accepted chain.
✘ A participant choosing to extend an existing path in the block chain indicates a
vote towards consensus on that path. The longer the path, the more computation
was expended building it.
17. Consensus Process = Mining
✘Originally the digital wallet could also participate in the consensus process by attempting to
secure the network directly .This process is known as “mining”
✘Mining involves attempting to find a numerical value, known as a “nonce” that when
combined with all open transactions can be “hashed” into a value that satisfies a certain
“difficulty”
✘Custom, purpose built-hardware is used
18. “Proof of Work” -Process
This is the way new Bitcoins are created.
Miners publish blocks on the blockchain. As a reward for publishing blocks, they get to keep
Bitcoins. (50 for the first 4 years, 25 then 12.5 now, halving every four years)
Miners also get transaction fees
Race to find a conforming hash every 10 minutes
Don’t do it (unless you have cash, time, and an underutilized electrical engineering skill)
Incredibly competitive, Risky, High upfront investment
Technology is changing rapidly
Now requires specialized hardware (ASIC chip)
Miners reasonably must join a guild (Miners Pool)
The combined computing power of the miners is thousands of times more powerful than
the most powerful super computers in the world
19. “Proof of Work” -Process
Hashcash algorithm designed to prevent spam
A hash is an apparently random set of 256 bits
Every time you change something being hashed (for example, with a nonce) the hash completely
changes
There is a 50% chance the first bit might be 0
If you change the thing-to-be-hashed a little bit, you could try a few times and get one with the first bit
of 0
First 2 bits: 25% , First 10 bits: 0.0977%
Find a hash with the first 63 bits as 0 (0.00000000000000001%), and you can publish a block and win
12.5 Bitcoins
20. “Proof of Work”-continue
Hashing is straightforward, but not challenging
Unless the goal is to say, find me a hash value that satisfies a certain level of “difficulty”
For example, let’s say the challenge is find a hash-value that begins with a number of zeros,
for a given input
The Proof of Work comes from finding a number (known as a NONCE) that when added to
the input changes the output of the hash value to satisfy the difficulty.
In the Bitcoin world this is what “mining” is and in effect is little more than a lot of hash-
power spent on guessing winning lottery numbers that satisfy the difficulty of the problem
in order to obtain the reward from the network
21. Transaction Confirmation
Having a transaction provisionally accepted into a candidate block signals that the
network has verified that the inputs were viable
Every new block accepted into the chain after the transaction was accepted is considered a
confirmation
Coins are not considered mature until there have been 6 confirmations
New Coins created by the mining process are not valid until about 120 confirmations
This is to assure that a node with more than 51% of the total hash-power does not pull off
fraudulent transactions
23. Purchase / Exchange Bitcoins
In addition to mining bitcoins, they can be acquired from an exchange!
24. If you want to be Node (Miner)
Your computer will act as a full node which means:
Connecting to the bitcoin network
Downloading the blockchain
Storing the blockchain
Listening for transactions
Validating transactions
Passing on valid transactions
Listening for blocks
Validating blocks
Passing on valid blocks
Creating blocks
Mining’ the blocks
25. Features of Bitcoin
All-electronic
Provable value
Fast transactions
Low-cost transactions
No third-party trust required
Uncontrollable (Decentralized)
Irreversible trades
No double-spending
Some anonymity (pseudonymity)
Inflation resistant
Deflationary (Maximum of 21M issued)
International
Widely accepted as a currency
26. Uses For Bitcoin
Convenient online purchases
Micro-payments
Black-market transactions
Investment
A place to hide money
Gambling
Ransom
Escape currencies that are in trouble
International transactions and financing
Buying foreign goods
Paying foreign employees
27. Some technical notes
The Technology Behind BTC
Hashing (double-SHA256, RIPEMD-160)
Proof-of-work (hashcash proof)
Dual key encryption (Elliptical Curve Digital Signature Algorithm, Merkle
Trees )
Peer-To-Peer Networking (similar to IRC Internet Relay Chat)