This document provides an overview of consensus models for distributed systems, including both "fast" and "slow" consensus. For slow consensus, it describes proof-of-work protocols like Bitcoin which achieve eventual consistency through mining, and proof-of-stake protocols which select validators randomly based on their stake. For fast consensus, it outlines private and federated models with a known set of validators, as well as delegated proof-of-stake and cryptographic sortition approaches. The document serves as a quick introduction to different consensus algorithms and their tradeoffs.
Intro to Blockchain - And, by the way, what the heck is proof-of-work?Jim Flynn
An overview of bitcoin and the blockchain with a more in-depth description of proof of work (POW). Conde samples used to demonstrate the concepts behind POW are available at http://jamespflynn.com.
Metadata in the Blockchain: The OP_RETURN ExplosionCoin Sciences Ltd
With the addition of OP_RETURN outputs in version 0.9, it became possible to attach arbitrary pieces of information to bitcoin transactions. This turns bitcoin into a low-level communications protocol, just like TCP/IP, on which many new applications can be built.
Despite its powerful features, bitcoin is also limited, costly and inefficient compared to TCP/IP. After discussing which sorts of applications make this trade-off worthwhile, we talk about CoinSpark, a new open source protocol for enhancing bitcoin transactions, which makes extensive use of OP_RETURNs.
Intro to Blockchain - And, by the way, what the heck is proof-of-work?Jim Flynn
An overview of bitcoin and the blockchain with a more in-depth description of proof of work (POW). Conde samples used to demonstrate the concepts behind POW are available at http://jamespflynn.com.
Metadata in the Blockchain: The OP_RETURN ExplosionCoin Sciences Ltd
With the addition of OP_RETURN outputs in version 0.9, it became possible to attach arbitrary pieces of information to bitcoin transactions. This turns bitcoin into a low-level communications protocol, just like TCP/IP, on which many new applications can be built.
Despite its powerful features, bitcoin is also limited, costly and inefficient compared to TCP/IP. After discussing which sorts of applications make this trade-off worthwhile, we talk about CoinSpark, a new open source protocol for enhancing bitcoin transactions, which makes extensive use of OP_RETURNs.
A CIO Roundtable briefing on the disruptive nature of the Blockchain, Bitcoin and Ethereum. We'll take a look at Smart Contracts, Digital Tokens and a dozen or so use cases within Financial Services, IOT, Healthcare and Government.
Topics Covered:
What is the BlockChain
Economics behind Digital Currencies
Blockchain Trivia
Use Cases
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
The presentation slides for a blockchain event - All About TenX Cryptopayment Technology, Lightning Network & Bitcoin Mining.
Presenter: Sun Sagong
Venue: Tenx (Singapore)
Date: 07Feb2018
Blockchain Technology - The Next Superpower By Priyank VaghelaPriyankVaghela
What is Blockchain Technology?
Basics of Blockchain
How Does Blockchain work?
Blockchain Timeline
What Blockchain can store?
What is Bitcoin?
BItcoin vs Blockchain
Slides from my talk at CryptoMountain event in Davos. This is a less technical version of my slides on consensus algorithms for blockchain and distributed ledger technology
Presentation of sidechains as Blockstream currently defines them (December 2014).
LaTeX sources : https://www.dropbox.com/sh/yoz9mmfsom6b4yx/AAD1FK6xhFuyohbxdanXOEz0a?dl=0
This slidedeck was used at the first Blockchain Vlaanderen meetup in Leuven. It features a live (and open-source) demonstration of two usecases with Multichain.
A Complete Beginners Guide to Blockchain Technology Part 6 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
Apart from Proof of Work there are many other Consensus Mechanisms being discussed. What are they and what are their pros and cons. (Proof of Stake, Proof of Elapsed Time, Proof of Authority, Proof of Burn, Proof of Authority, Byzantine Fault Tolerance, Proof of Importance)
An introduction to Ethereum, the peer to peer computing framework based on the blockchain design. It describes how Ethereum relates to earlier blockchain technologies and how it represents an evolution of these technologies
Consensus Algorithms: An Introduction & AnalysisZak Cole
When evaluating blockchain networks, consensus mechanism and design are an imperative aspect of system function. While effective implementations should meet technical criteria specific to distributed computational environments, use case should also be taken into consideration.
This webinar will focus on illustrating these concepts while providing a high-level overview of popular consensus algorithms such as Paxos, Aura, Clique, Proof-of-Work, and Proof-of-Stake. Please join us in the discussion – whether you wish to learn about the basics of consensus algorithms or if you have deeper questions on performance, security, or suitability.
A CIO Roundtable briefing on the disruptive nature of the Blockchain, Bitcoin and Ethereum. We'll take a look at Smart Contracts, Digital Tokens and a dozen or so use cases within Financial Services, IOT, Healthcare and Government.
Topics Covered:
What is the BlockChain
Economics behind Digital Currencies
Blockchain Trivia
Use Cases
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
The presentation slides for a blockchain event - All About TenX Cryptopayment Technology, Lightning Network & Bitcoin Mining.
Presenter: Sun Sagong
Venue: Tenx (Singapore)
Date: 07Feb2018
Blockchain Technology - The Next Superpower By Priyank VaghelaPriyankVaghela
What is Blockchain Technology?
Basics of Blockchain
How Does Blockchain work?
Blockchain Timeline
What Blockchain can store?
What is Bitcoin?
BItcoin vs Blockchain
Slides from my talk at CryptoMountain event in Davos. This is a less technical version of my slides on consensus algorithms for blockchain and distributed ledger technology
Presentation of sidechains as Blockstream currently defines them (December 2014).
LaTeX sources : https://www.dropbox.com/sh/yoz9mmfsom6b4yx/AAD1FK6xhFuyohbxdanXOEz0a?dl=0
This slidedeck was used at the first Blockchain Vlaanderen meetup in Leuven. It features a live (and open-source) demonstration of two usecases with Multichain.
A Complete Beginners Guide to Blockchain Technology Part 6 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
Apart from Proof of Work there are many other Consensus Mechanisms being discussed. What are they and what are their pros and cons. (Proof of Stake, Proof of Elapsed Time, Proof of Authority, Proof of Burn, Proof of Authority, Byzantine Fault Tolerance, Proof of Importance)
An introduction to Ethereum, the peer to peer computing framework based on the blockchain design. It describes how Ethereum relates to earlier blockchain technologies and how it represents an evolution of these technologies
Consensus Algorithms: An Introduction & AnalysisZak Cole
When evaluating blockchain networks, consensus mechanism and design are an imperative aspect of system function. While effective implementations should meet technical criteria specific to distributed computational environments, use case should also be taken into consideration.
This webinar will focus on illustrating these concepts while providing a high-level overview of popular consensus algorithms such as Paxos, Aura, Clique, Proof-of-Work, and Proof-of-Stake. Please join us in the discussion – whether you wish to learn about the basics of consensus algorithms or if you have deeper questions on performance, security, or suitability.
Distributed Consensus: Making Impossible PossibleHeidi Howard
In this talk, we explore how to construct resilient distributed systems on top of unreliable components. Starting, almost two decades ago, with Leslie Lamport’s work on organising parliament for a Greek island. We will take a journey to today’s datacenters and the systems powering companies like Google, Amazon and Microsoft. Along the way, we will face interesting impossibility results, machines acting maliciously and the complexity of today’s networks. Ultimately, we will discover how to reach agreement between many parties and from this, how to construct new fault-tolerance systems that we can depend upon everyday.
Distributed Consensus: Making Impossible Possible by Heidi howardJ On The Beach
In this talk, we explore how to construct resilient distributed systems on top of unreliable components. Starting, almost two decades ago, with Leslie Lamport’s work on organising parliament for a Greek island. We will take a journey to today’s datacenters and the systems powering companies like Google, Amazon and Microsoft. Along the way, we will face interesting impossibility results, machines acting maliciously and the complexity of today’s networks. Ultimately, we will discover how to reach agreement between many parties and from this, how to construct new fault-tolerance systems that we can depend upon everyday.
Distributed Consensus: Making Impossible Possible [Revised]Heidi Howard
In this talk, we explore how to construct resilient distributed systems on top of unreliable components. Starting, almost two decades ago, with Leslie Lamport’s work on organising parliament for a Greek island. We will take a journey to today’s datacenters and the systems powering companies like Google, Amazon and Microsoft. Along the way, we will face interesting impossibility results, machines acting maliciously and the complexity of today’s networks. Ultimately, we will discover how to reach agreement between many parties and from this, how to construct new fault-tolerance systems that we can depend upon everyday.
There have never been more commercial tools available for building distributed data apps — from cloud hosting services, to cloud-native databases, to cloud-based analytics platforms. So why is it still so hard to make a successful app with a global user base?
One of the toughest challenges cloud offerings take on is the problem of consensus, abstracting away most of the complexity. That's no small feat, given that this is a hard enough problem that people spend years getting a PhD just to understand it! Unfortunately, while buying off-the-shelf cloud services can accelerate the path to an MVP, it also makes optimization tough. How will we scale during a period of rapid user growth? How do we do I18n and l10n or guarantee a good UX for users on the other side of the world? How do we prevent replication that might get us into legal trouble?
In this talk, we'll consider several case studies of global apps (both successful and otherwise!), talk about the limitations of off-the-shelf consensus, and consider a future where everyday developers can use open source tools to build distributed data apps that are easier to reason about, maintain, and tune.
Distributed Consensus: Making the Impossible PossibleC4Media
Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/29faOI5.
Heidi Howard explores how to construct resilient distributed systems on top of unreliable components. Howard discusses today’s datacenters and the systems powering companies like Google, Amazon and Microsoft, as well as which algorithms are best suited to different situations. Filmed at qconlondon.com.
Heidi Howard is currently studying towards PhD at the Cambridge University, Computer Lab. Her research interest is fault-tolerance, consistency and consensus in modern distributed systems. Heidi has also previously worked as research assistant and undergraduate researcher on topics such as middlebox traversal, DNS, privacy preserving systems and wireless community networks.
Blockchain Ecosystem and Cryptocurrency RegulationsAmir Rafati
A blockchain is a general digital ledger of transactions that are executed on the network, e.g. using Bitcoin to buy a cup of coffee is a transaction.
All users of the network, ‘Nodes’, have a copy of the transaction records and can access them freely, a role previously played by centralized institutions. Therefore, the blockchain network is ‘decentralized’.
The Power of Determinism in Database SystemsDaniel Abadi
Slides for Daniel Abadi talk at UC Berkeley on 10/22/2014. Discusses the problems with traditional database systems, especially around modularity and horizontal scalability, and shows how deterministic database systems can help.
Introduction to Blockchain Governance ModelsGokul Alex
The presentation on the history and emergence of distributed consensus and the contemporary aspects of Blockchain Governance presented for the Global FinTech and Blockchain Forum organised by Pyramid Learning Platforms.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
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.
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/
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
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
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Connector Corner: Automate dynamic content and events by pushing a button
A quick introduction to Consensus Models
1. Consensus Models
A quick introduction to
oded.noam@kik.comOded Noam, Blockchain Architect kin.kik.com
2. History: Distributed Systems
• Attempt to solve scale, geo-redundancy and/or custody of systems
• Handle two types of faults:
• Crashes (incoherent state)
• Byzantine faults (1982)
● CAP theorem (consistency/availability/partition-tolerance: can’t have
more than 2)
● FLP Impossibility (no consensus in finite time with faulty processes)
• Abstract use-case: Replicated State Machine
3. (Byzantine Faults)
• Generals need to decide attack/retreat
• Half-hearted attack will result in failure
• Communication via couriers (peer-to-peer)
• Traitor may create false consensus
4. “Fast” vs “Slow” Consensus
● “Fast” (weakly synchronous / final): system-wide consensus in bound
timing
● Handle faults: crashes (incoherent state) and byzantine faults
● Known set of verifiers
● “Slow” (eventual / asynchronous / non-final): distribute the mandate to
sign blocks, and determine consensus in retrospect (e.g. Longest-
chain or GHOST protocols)
● Can be permissionless/open
5. Slow Consensus: Proof-of-Work (1)
• Proposed by Naor and Dwork (1993) for eliminating e-mail spam
• Whoever solves a puzzle can publish a block
• Solving costs money in computer time, electricity and cooling
• Nontrivial balance between worth of network and cost of its protection
6. • Target difficulty is 000000000FFFFFFFFFFFFF
Construct block:
Put “0” in nonce, hash the block
→ 6ebd2efb6476025951da175a82ce0fbc
Put “1” in the nonce, hash the block
→ 8d678c54ff53cac1efd6d62697aeb5a0
…
Put “59324502” in the nonce, hash the block
→ 0000000009efb30f7e7ca5bda314561e winner!
Slow Consensus: Proof-of-Work (2)
7. • Bitcoin, Ethereum: hash(block+nonce) < difficulty
• Other variants: Memory-hard PoW (ZCash); Quantum resistant PoW;
Proof-of-useful-work (Primecoin)
• Trade-off between block time and forking
• High carbon footprint
Slow Consensus: Proof-of-Work (3)
8. • Replace PoW with block signing by weighted-random stakeholder
• Some require participating verifiers to put security deposit (“bonding”)
● Nothing-at-stake problem: leader can sign competing blocks
● Circular logic problem: stakeholders vote on stakeholding
Examples: Casper (Ethereum), Ouroboros (Cardano)
Slow Consensus: Proof-of-Stake
9. Fast Consensus Protocols
• Widely used in distributed systems (databases, KVS, filesystems)
• Variety of consensus algorithms, for example
• PAXOS variants (multi-paxos, byzantine-paxos & more)
• PBFT
● BA*
• Known set of verifiers, preferably small → BIG CHALLENGE
10. Fast Consensus: Private
• Known set of verifiers: owned by one entity
• Controlled execution environment; enforceable adherence to protocol
• Centralized; decentralization (?) by consortium
Examples: Hyperledger
11. Fast Consensus: Federation
• Eliminate central governance of consortium
• Each node has a set of trusted verifiers
• Modified consensus algorithm to allow partially-overlapping trusted
sets; each node may see different projection of the ledger
Examples: Ripple, Stellar
12. Fast Consensus: Delegated PoS
• Stakeholders periodically elect verifiers to represent them
• Specific criticism: delegate corruption, voter indifference
(parliamentary democracy)
• Other POS problems (nothing-at-stake problem, circular logic)
Examples: BitShares, Steem.it, EOS, Waves
13. Fast Consensus: AlgoRand
• Cryptographic sortition: incorruptible selection of random verifier set
each round
• Like jury duty, every user may be selected to be verifier
• Not ready for production yet; some practical challenges still unsolved
