This document provides examples to explain the Swirlds hashgraph consensus algorithm. It shows a hashgraph growing over time as members create events and gossip with each other. Each event contains cryptographic hashes linking it to previous events. Rounds are defined, with each member's first event in a round being a "witness." Elections are held for witnesses to determine if they are "famous," with later witnesses counting votes. The goal is for all members to reach consensus on the order and timestamps of all events.
Threat hunting foundations: People, process and technology.pptxInfosec
Ever wonder what threat hunting is all about? Join Infosec Principal Security Researcher Keatron Evans as he breaks down the basics of what it’s like to have a career hunting down potential cyber threats.
Join us on for an inside look at a day in the life of a threat hunter, including:
Why threat hunters are more critical today than ever before
Knowledge and skills needed to drive threat hunting success
Live demos of essential threat hunting skills and tools used to detect and mitigate adversarial behavior
One lucky attendee will win a free year of Infosec Skills. Complete the form to save your seat!
P.S. Want to go even deeper into threat hunting? Don’t miss our advanced threat hunting session on June 28, Join the hunt: Threat hunting for proactive cyber defense.
Containerizing your Security Operations CenterJimmy Mesta
AppSec USA 2016 talk on using containers and Kubernetes to manage a variety of security tools. Includes best practices for securing Kubernetes implementations.
Threat hunting foundations: People, process and technology.pptxInfosec
Ever wonder what threat hunting is all about? Join Infosec Principal Security Researcher Keatron Evans as he breaks down the basics of what it’s like to have a career hunting down potential cyber threats.
Join us on for an inside look at a day in the life of a threat hunter, including:
Why threat hunters are more critical today than ever before
Knowledge and skills needed to drive threat hunting success
Live demos of essential threat hunting skills and tools used to detect and mitigate adversarial behavior
One lucky attendee will win a free year of Infosec Skills. Complete the form to save your seat!
P.S. Want to go even deeper into threat hunting? Don’t miss our advanced threat hunting session on June 28, Join the hunt: Threat hunting for proactive cyber defense.
Containerizing your Security Operations CenterJimmy Mesta
AppSec USA 2016 talk on using containers and Kubernetes to manage a variety of security tools. Includes best practices for securing Kubernetes implementations.
The SOC analyst training program is meticulously designed by the subject matter experts at Infosec Train. The training program offers a deep insight into the SOC operations and workflows. It is an excellent opportunity for aspiring and current SOC analysts (L1/L2/L3) to level up their skills to mitigate business risks by effectively handling and responding to security threats.
https://www.infosectrain.com/courses/soc-analyst-expert-training/
The Information Security Community on LinkedIn, with the support of Cybereason, conducted a comprehensive online research project to gain
more insight into the state of threat hunting in security
operation centers (SOCs). When the 330 cybersecurity and IT professionals were asked what keeps them up at night, many comments revolved around a central theme of undetected threats slipping through an organization’s defenses. Many
responses included “unknown” and “advanced” when
describing threats, indicating the respondents understand
the challenges and fear those emerging threats.
Read the full report here.
In our webinar “What is Threat Hunting and why do you need it?" we discussed the folowing key points:
1. What Threat hunting is.
2. Why it is becoming so popular and what kinds of attacks are making it necessary.
3. What the challenges are.
4. Threat Hunting and Investigation services for attacks.
5. Case studies.
Find out more on https://www.pandasecurity.com/business/adaptive-defense/?utm_source=slideshare&utm_medium=social&utm_content=SM_EN_WEB_adaptive_defense&track=180715
Join the hunt: Threat hunting for proactive cyber defense.pptxInfosec
As threat hunters, you already know staying ahead of the adversary demands a proactive approach to threat detection and response. Don your virtual threat hunting gear and join Infosec Principal Security Researcher Keatron Evans as he goes sleuthing for cyber threats.
Join us for practical threat hunting insights and career recommendations, including:
Threat hunting knowledge and skills to accelerate your career
How to help clients navigate the threat hunting toolbox and prioritize technology investments
Live demos of notoriously hard-to-detect adversarial behavior like memory-only malware and living-off-the-land techniques
One lucky attendee will win a free year of Infosec Skills. Complete the form to save your seat!
P.S. Don’t miss our novice-level threat hunting session: Threat hunting foundations: People, process and technology.
Effective Threat Hunting with Tactical Threat IntelligenceDhruv Majumdar
How to set up a Threat Hunting Team for Active Defense utilizing Cyber Threat Intelligence and how CTI can help a company grow and improve its security posture.
Durante l’intervento verranno presentati i cardini del processo di ricerca delle informazioni mediante la consultazione di fonti di pubblico accesso. Sarà illustrata la teoria alla base di questo processo che prevede l’identificazione delle fonti, la selezione e la valutazione del loro contenuto informativo per arrivare infine all’utilizzo stesso dell’informazione estratta. Nella seconda fase della presentazione verranno mostrati i tool e le metodologie per l’estrazione di informazioni mediante l’analisi di documenti, foto, social network e altre fonti spesso trascurate. In ultimo saranno mostrati sistemi in grado di correlare diverse informazioni provenienti dalle fonti aperte e verranno discussi i relativi scenari di utilizzo nonché le possibili contromisure.
TALLINN MANUAL & GLOBAL CYBER WARFARE POLICIESanupriti
The presentation is one unique presentation peculiar to TALLINN MANUAL version 1.0 and 2.0. Along with is discussed cyber policy attempts of other countries.The Tallinn Manual has long been the flagship research initiative of the NATO CCDCOE. The original Tallinn Manual (published in 2013 by Cambridge University Press) addressed the most severe cyber operations followed by version 2.0. The presentation cover the origin details of why this manual arrived at the global scene and what followed around at the global attempts for framing the global cyber policy.
Cyber Security : An attempt to assimilate and technically understand itanupriti
his presentation is a simple take on with respect to the statistics and maths involved behind the IT giants.It discusses the strange patents of likes of FB and then concludes its way through certain small cyber hygiene measures.
The SOC analyst training program is meticulously designed by the subject matter experts at Infosec Train. The training program offers a deep insight into the SOC operations and workflows. It is an excellent opportunity for aspiring and current SOC analysts (L1/L2/L3) to level up their skills to mitigate business risks by effectively handling and responding to security threats.
https://www.infosectrain.com/courses/soc-analyst-expert-training/
The Information Security Community on LinkedIn, with the support of Cybereason, conducted a comprehensive online research project to gain
more insight into the state of threat hunting in security
operation centers (SOCs). When the 330 cybersecurity and IT professionals were asked what keeps them up at night, many comments revolved around a central theme of undetected threats slipping through an organization’s defenses. Many
responses included “unknown” and “advanced” when
describing threats, indicating the respondents understand
the challenges and fear those emerging threats.
Read the full report here.
In our webinar “What is Threat Hunting and why do you need it?" we discussed the folowing key points:
1. What Threat hunting is.
2. Why it is becoming so popular and what kinds of attacks are making it necessary.
3. What the challenges are.
4. Threat Hunting and Investigation services for attacks.
5. Case studies.
Find out more on https://www.pandasecurity.com/business/adaptive-defense/?utm_source=slideshare&utm_medium=social&utm_content=SM_EN_WEB_adaptive_defense&track=180715
Join the hunt: Threat hunting for proactive cyber defense.pptxInfosec
As threat hunters, you already know staying ahead of the adversary demands a proactive approach to threat detection and response. Don your virtual threat hunting gear and join Infosec Principal Security Researcher Keatron Evans as he goes sleuthing for cyber threats.
Join us for practical threat hunting insights and career recommendations, including:
Threat hunting knowledge and skills to accelerate your career
How to help clients navigate the threat hunting toolbox and prioritize technology investments
Live demos of notoriously hard-to-detect adversarial behavior like memory-only malware and living-off-the-land techniques
One lucky attendee will win a free year of Infosec Skills. Complete the form to save your seat!
P.S. Don’t miss our novice-level threat hunting session: Threat hunting foundations: People, process and technology.
Effective Threat Hunting with Tactical Threat IntelligenceDhruv Majumdar
How to set up a Threat Hunting Team for Active Defense utilizing Cyber Threat Intelligence and how CTI can help a company grow and improve its security posture.
Durante l’intervento verranno presentati i cardini del processo di ricerca delle informazioni mediante la consultazione di fonti di pubblico accesso. Sarà illustrata la teoria alla base di questo processo che prevede l’identificazione delle fonti, la selezione e la valutazione del loro contenuto informativo per arrivare infine all’utilizzo stesso dell’informazione estratta. Nella seconda fase della presentazione verranno mostrati i tool e le metodologie per l’estrazione di informazioni mediante l’analisi di documenti, foto, social network e altre fonti spesso trascurate. In ultimo saranno mostrati sistemi in grado di correlare diverse informazioni provenienti dalle fonti aperte e verranno discussi i relativi scenari di utilizzo nonché le possibili contromisure.
TALLINN MANUAL & GLOBAL CYBER WARFARE POLICIESanupriti
The presentation is one unique presentation peculiar to TALLINN MANUAL version 1.0 and 2.0. Along with is discussed cyber policy attempts of other countries.The Tallinn Manual has long been the flagship research initiative of the NATO CCDCOE. The original Tallinn Manual (published in 2013 by Cambridge University Press) addressed the most severe cyber operations followed by version 2.0. The presentation cover the origin details of why this manual arrived at the global scene and what followed around at the global attempts for framing the global cyber policy.
Cyber Security : An attempt to assimilate and technically understand itanupriti
his presentation is a simple take on with respect to the statistics and maths involved behind the IT giants.It discusses the strange patents of likes of FB and then concludes its way through certain small cyber hygiene measures.
IETE mid-term symposium on digital forensics and information security : 23 M...anupriti
While anyone of us discusses cryptocurrency, we invariably hover around BITCOIN only , but as on date we have 2000+ cryptocurrencies in the world and the sad thing is CRYPTOCURRENCY CRIMES ARE RISING FAST undeterred.This presentation, given at the IETE mid term symposium on 23rd May 2020 ,brings a brief over view of how cryptocrimes work and what are the challenges around?
Coalition of IoT and Blockchain: Rewards and Challengesanupriti
IoT and Blockchain are two evolving technologies which are gradually realizing immense potential to be a decisive part of future of mankind ecosystem. Blockchain and IoT, both are envisaged to bring in a plethora of advantages including better control, communication, transparency and more significantly realizing digital trust without any third party intervention. Both of these technologieshave immense potential for exploitation in a smart nation concept. The advantages being realized are potent enough for definite implementation ahead but they come with an austere package of security concerns which if not taken care at the design stage can lead to pandemonium beyond control because of the billion plus connected things. Even atdesign stage, one can appreciate that it will be envisaging beyond control to close all security vulnerabilities and zero day’s exploits of future. But then Blockchain is an inexpugnable solution to shut all these securities imperils. This paper builds upon the advantages of the union of these two evolving technology behemoths, their union and solutions vide Blockchain to the challenges in the way ahead
Proof of Work and connect with BYZANTINE Generalsanupriti
Proof of Work (PoW) is the original blockchain consensus algorithm, and is used in projects such as Bitcoin. It is the mechanism that enables users on a blockchain network to reach an agreed ‘truth’. A proof of work is essentially an answer to a complex mathematical problem. It takes a lot of work to find the Nonce but is easy for others to validate.PoW solves the Byzantine Generals Problem as it achieves a majority agreement without any central authority, in spite of the presence of unknown/potentially untrustworthy parties and despite the network not being instantaneous.This presentation brings out the concept Byzantine Generals proof and its connect with Bitcoin.
BLOCKCHAIN ,BITCOIN & CRYPTOCURRENCIES WORLD : MECHANICS AND CYBER CRIMEanupriti
The world of Blockchain and Cryptocurrencies is undeniably amazing and has infinity to explore at hands.Recently I took on a 4 hour session at the prestigious Central Bureau of Investigations,CBI Academy ,Ghaziabad, vide Indian Technical and Economic Cooperation Programme organised by Ministry of External Affairs , to cover right from scratch to overview of mechanics and architecture of how this world works.Sharing here the presentation for info and awareness of anyone who is interested to take a dip in this domain and related cyber crime activities.
Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies anupriti
Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies was held at G D Goenka University, Sohna Road,Gurgaon on 22nd Feb 2018.Sharing here the presentation I gave for info.Readers may contact me for any clarifications on the subject content please.
Gave this presentation and talk on the still evolving field of BITCOIN FORENSICS that brings out the technical overview and evolving forensics developments in the domain at the BSides Security Conference ie community-driven framework for building events for and by information security community members. The goal is to expand the spectrum of conversation beyond the traditional confines of space and time.
Presentation I gave at 4th International Information Security Meet in the Hakon 2017 conference on 08th Oct 2017.Covers technical overview of the concept and take off essentials for Bitcoin crime investigators.Details at http://www.hakonindia.org/hakon-2017-speakers/
Presentation I gave at BRIGHTTALK webinar in the BLOCKCHAIN SUMMIT on 10th Oct 2017.Covers technical overview of the concept and take off essentials for Bitcoin crime investigators.Details at https://www.brighttalk.com/webcast/1570/272431/bitcoin-forensics
The increased use of cryptocurrencies such as Bitcoin among an increasing user base has opened a new avenue of research in the field of digital forensics ie Bitcoin Forensics. Since the creation of Bitcoin in 2008, cryptocurrencies have begun to make a presence in the world of e-commerce. Cryptography serves as the underlying foundation for Bitcoin, which gives it the benefits of confidentiality, integrity, non repudiation and authentication. Having been designed and built upon the foundation of these four objectives makes Bitcoin an attractive alternative to mainstream currency and provides users with the benefits of payment freedom, security, very low fees, and fewer risks for merchants.But with a pleothra of advantages that it offers,there is a definete side to worry too and thats the money laundering transactions.On an average it is estimated that around 3 lakh bitcoin transactions happen inside a day and its not an easy task any day for a forensic investigator to trace the origins here.This presentation will bring out the technical overview and evolving forensics developments in the domain.
Blockchain and Bitcoin : A Technical Overviewanupriti
Blockchain is a distributed database that is used to maintain a continuously growing list of records, called blocks. Each block contains a timestamp and a link to a previous block and is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks.Bitcoin is a proven application that runs on BLOCKCHAIN.This ppt gives the reader an over view of the concept of BLOCKCHAIN.The same was presented by self on 20th June 2017 at Gurgaon Commissioner of Police office during Summer Internship Program under aegis of Shri Rakshit Tandon
Equation Group : Advanced Secretive Computer Espionage Groupanupriti
The Equation Group is a highly advanced secretive computer espionage group, suspected by security expert Claudio Guarnieri and unnamed former intelligence operatives of being tied to the United States National Security Agency (NSA). Because of the group's predilection for strong encryption methods in their operations, the name Equation Group was chosen by Kaspersky Lab, which discovered this operation and also documented 500 malware infections by the group's tools in at least 42 countries.This presentation gives an over view in brief based on the Kaspersky Report.
This small presentation wil sail through a set of questions for any web/Internet user and will mark for every question as the user decides to answer.The safety score as it ends up lets the user know of where he stands in terms of IT SECURITY on the web!!!!
This presentation brings out few basic steps that every android phone user should configure to harden his/her device.Although the list is not completly exhaustive but it brings out basic necessities as expected from any smart user.
Harden your LinkedIn Settings : A Necessity Nowanupriti
Most of us are part of various Social Engineering Sites and keep updating ourselves via status updates, pictures and tweeting small life updates. Related privacy and security issues in respect of these social engineering sites available is already a serious concern among users. Additionally for these all social engineering sites/applications whether accessible on a desktop or a mobile, we all are not so serious responding and interacting but that’s the difference when we see viz-a-viz LinkedIn. When it is LinkedIn…we are mostly serious…no jokes, no clips, no tagging, no personal comments, no WOWs…it’s all professional. And when most of us take it seriously, we also feed serious inputs on it. But do we take necessary precautions too?...I have mostly seen a negated curve amongst my friend circle….hardly anyone has spared time to configure LinkedIn Privacy and Security settings. In this post I bring you out basic and necessary configuration steps involved to harden your LinkedIn interface to the world.
APT 28 :Cyber Espionage and the Russian Government?anupriti
Russia may be behind a long-standing, careful campaign designed to steal sensitive data relating to governments, militaries and security firms worldwide.This presentation based on a report made public by FireEye brings an over view of their opinion.....uploaded here just for general info to understand how its all happening!!!!
An advanced piece of malware, known as ‘Regin’, has been used in systematic spying campaigns against a range of international targets including government agencies and businesses since at least 2008 vide IT security firms Symantec and Kaspersky Lab reports both released on 24th Nov 2014.This ppt brings you an overview of the threat in brief.The piece of malware is unique in the sense that it's structure displays a degree of technical competence rarely seen.Stuxnet looks a decent past....with this complexity
This ppresentation brings out a brief over view of WireLurker,the first of a kind of malware family that has made the Apple to rot...never in the history of unquestionable iOS/Mac devices has such a thing been seen or heard...with such a severe beating...the ppt is based on a report made recently public by Palo Alto Networks®...
The presentation starts with a blank slate for those who have no idea of what cloud and virtualization world is to gradually building up till handling security issues.If any one wants the soft copy,please ask for it at anupam@blumail.org
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.
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/
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.
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
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
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.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
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.
Essentials of Automations: Optimizing FME Workflows with Parameters
Hashgraph : An over view with example
1. Swirlds Technical Report SWIRLDS-TR-2016-02 1
HASHGRAPH CONSENSUS:
DETAILED EXAMPLES
LEEMON BAIRD BAIRD@SWIRLDS.COM
DECEMBER 11, 2016
SWIRLDS TECH REPORT SWIRLDS-TR-2016-02
ABSTRACT: The Swirlds hashgraph consensus algorithm is explained through a series
of examples on a hashgraph. Each page shows the hashgraph with annotations
explaining a step of the algorithm. This covers the core algorithm, from creating
transactions, through finding their consensus order and timestamps. The
important terms are defined and illustrated on the following pages:
April 7, 2017: this version includes corrections.
8 Round created
9 Witness
10 Famous witness
10 Election
10 Vote
11 See
15 Strongly see
15 Supermajority
19 Decide
19 Round created
24 Round received
24 Consensus timestamp
28 Consensus order
2 Hashgraph
2 Member
2 Event
2 Transaction
2 Consensus
2 Order
2 Timestamp
3 Gossip protocol
4 Self-parent
4 Other-parent
7 Graph
7 Hash
7 Hashgraph
2. Swirlds Technical Report SWIRLDS-TR-2016-02 2
A B C D
=
This figure is a hashgraph. It grows upward over time. Every
participant keeps a copy of it in memory.
In this example, there are four members (full nodes) in the
network. The members are Alice, Bob, Carol, Dave, and are
represented by the 4 lines labeled A, B, C, D.
Each member starts by creating an event, which is a small data
structure in memory, and which is represented here by a gray
circle.
Each event is a container for zero or more transactions. The
goal of the Swirlds hashgraph consensus algorithm is for the
members of the community to come to a consensus
(agreement) on the order of the events (and thus the order of
transactions inside the events), and to agree on a timestamp
for each event (and so for each transaction). It should be hard
for attackers to prevent consensus, or to force different
members to come to a different “consensus”, or to unfairly
influence the order and timestamps that are agreed.
3. Swirlds Technical Report SWIRLDS-TR-2016-02 3
A B C D
=
The community runs a gossip protocol, which means that each
member repeatedly calls others at random to sync with them.
In this case, Bob randomly chose to call Dave. When they
connected over the internet, Bob sent Dave all the events he
knew that Dave did not yet know. In this case, it was just one
event: the one that Bob had created at the start.
Dave records the fact that this sync happened by creating a
new event. This is the new circle, which has lines going straight
down to his own last event, and diagonally down to Bob’s last
event. Thus, the graph of events forms a record of how the
members have communicated.
TECHNICAL DETAIL: Bob can avoid sending Dave events he already knows. Bob first tells Dave
how many events he knows about that were created by each member (i.e., 4 integers). Dave
tells Bob the same. Then they will both know exactly which events each should send the other.
If Bob has 13 events by Alice and Dave has 10, then Bob sends Alice’s last 3 events.
4. Swirlds Technical Report SWIRLDS-TR-2016-02 4
A B C D
=
hash
hash
timestamp
transactions
Event (signed by creator):
Dave’s new event is illustrated here.
An event is a data structure containing the two hashes of the
two events below itself (its self-parent and its other-parent).
In this case, the self-parent is Dave’s first event, and the other-
parent is Bob’s first event.
The event can optionally contain zero or more transactions
that Dave wants to send to the network. So an event is a
container for transactions. Dave also puts a timestamp of
when he created the event. He then digitally signs it. When
this event is gossiped, the signature will be sent along with it.
5. Swirlds Technical Report SWIRLDS-TR-2016-02 5
A B C D
=
Dave then sends Bob all his events (including the new one he
just created). Bob then creates a new event recording the fact
they synced, and including the hashes of the most recent
event by himself and the most recent event by Dave.
7. Swirlds Technical Report SWIRLDS-TR-2016-02 7
A B C D
=
This continues forever, growing a directed acyclic graph
upwards forever.
This is a graph connected by cryptographic hashes, so it is
called a hashgraph.
Each event contains the hashes of the events below it and is
digitally signed by its creator. So the entire graph of hashes is
cryptographically secure. It can always grow, but the older
parts are immutable, as strong as the cryptographic hash and
signature system used.
8. Swirlds Technical Report SWIRLDS-TR-2016-02 8
A B C D
=
4
3
2
1
Round
Created:
It is useful to define a round created for each event. A child
never has a round created before one of its parents. So as time
flows upward in the diagram, the round created can only stay
the same or increase.
A later slide will describe how the round created is calculated.
The important point is that as soon as you receive an event in
a sync, you can immediately calculate its round created. And
anyone else receiving it will calculate the same number.
Guaranteed.
TECHNICAL DETAIL: The definition is: the round created for an event is R or R+1, where R is
the max of the round created of its parents. It is R+1 if and only if it can strongly see a
supermajority of round R witnesses. This is explained in greater detail in later slides.
9. Swirlds Technical Report SWIRLDS-TR-2016-02 9
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
4
3
2
1
Round
Created:
The first event that Alice creates in each round is called a
witness. Her witnesses are labeled A1, A2, and A3 here. The
other members create witnesses similarly.
It is possible for a member to have no witnesses in a given
round.
TECHNICAL DETAIL: It is possible for a member to cheat by forking, or creating two events
with the same self parent. In that case, there might be two witnesses in the same round by
the same member. There are theorems proving that this won’t matter.
10. Swirlds Technical Report SWIRLDS-TR-2016-02 10
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
For each witness, we need to determine if it is a
famous witness. For example, we will determine if the witness
B2 is a famous witness.
This is done by considering the witnesses in the next round. So
the fame of B2 will be determined by first considering the
witnesses A3, B3, C3, and D3. The idea is for B2 to count as
famous if it is seen by many of the witnesses in the next round.
There is now an election, in which each of those witnesses will
vote on whether B2 is famous. There will be a separate
election for every witness, to determine its fame.
11. Swirlds Technical Report SWIRLDS-TR-2016-02 11
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
YES
The witness A3 can see B2. That means that there is an
entirely-downward path from A3 to B2. In other words, B2 is
an ancestor of A3. And A3 is a descendent of B2
A3 can see B2, so A3 will vote YES in the election for whether
B2 is famous.
TECHNICAL DETAIL: A3 sees all its ancestors except for those created by a member who
created a fork that is an ancestor of A3. In other words, A3 can see B2 if B2 is an ancestor of
A3, and the creator of B2 (who is Bob) did not create two events X and Y that both have the
same self-parent and are both ancestors of A3. So “seeing” is the same as “ancestor”, except
you can’t “see” cheaters.
14. Swirlds Technical Report SWIRLDS-TR-2016-02 14
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
YES
YES
YES
YES
D3 sees B2, so it votes YES.
All four witnesses voted YES, so we would expect that B2 will
be declared to be famous. But the election isn’t over yet! An
election isn’t over until the votes are counted.
The votes will be counted by the witnesses in the following
round. So B4 will count the votes. And D4 will also count the
votes.
The hashgraph doesn’t yet have an A4 or C4. But as time goes
on and more gossiping occurs, there may eventually be an A4
and C4, and then they will count the votes, too.
15. Swirlds Technical Report SWIRLDS-TR-2016-02 15
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
YES
YES
YES
YES
B4 strongly sees:
YES
B4 will collect the votes from every round-3 witness that it
strongly sees. To strongly see a witness, it isn’t enough for
there to be a single downward path to it. There must be
enough different paths to it so that together, the paths go
through a supermajority of the population.
A supermajority is any number that is more than two thirds of
the population. In this example, there are 4 members in the
population, so any 3 of them constitute a supermajority.
In this example, B4 is able to strongly see A3. The red path
goes from B4 to A3 through Alice and Bob. The green path
goes through Alice, Bob, and Dave. There are no paths from
B4 that go through Carol to get to A3. But that’s OK, because
Alice, Bob, and Dave make up a supermajority. So Carol isn’t
needed. In fact, the green path alone would have been
enough. The red path wasn’t needed.
So, B4 can strongly see A3. Therefore, B4 collects the vote
from A3 (which is YES).
16. Swirlds Technical Report SWIRLDS-TR-2016-02 16
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
YES
YES
YES
YES
B4 strongly sees:
YES, YES,
B4 strongly sees B3, because the red path goes through Alice
and Bob, and the green path goes through Bob and Dave. In
this case, both paths were needed to reach the supermajority.
17. Swirlds Technical Report SWIRLDS-TR-2016-02 17
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
YES
YES
YES
YES
B4 strongly sees:
YES, YES, YES,
B4 strongly sees C3, and so collects another YES vote.
TECHNICAL DETAIL: if a path starts at Bob and ends at Carol, then it automatically counts as
going through Bob and Carol. In other words, the endpoints of the path are counted, too.
18. Swirlds Technical Report SWIRLDS-TR-2016-02 18
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
YES
YES
YES
YES
B4 strongly sees:
YES, YES, YES, YES
B4 strongly sees D3, and so collects another YES vote.
19. Swirlds Technical Report SWIRLDS-TR-2016-02 19
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
At this point, B4 has received YES notes from a supermajority,
so B4 decides that the election result is YES. Color B2 green to
show that it is now famous. That is the consensus decision.
If B4 had seen 3 YES and 1 NO, it would still decide YES,
because that’s a supermajority.
If B4 had seen 3 YES votes and no other votes (because it
couldn’t strongly see one of the witnesses), it would still
decide YES, because that’s a supermajority.
We need for B4 to strongly see a supermajority of witnesses,
in order to even have a chance at deciding. Therefore, we use
this to define the round created. If an event X has parents
with a maximum round created of R, then that event will
usually be round R, too. But if that event can strongly see a
supermajority of round R witnesses, then that event is defined
to be round R+1, and so is a witness. In other words, an event
is promoted to the next round when it can strongly see a
supermajority of witnesses in the current round.
20. Swirlds Technical Report SWIRLDS-TR-2016-02 20
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
NO
NO
YES
NO
Now we run an election for whether C2 is famous.
The yellow path shows that C3 can see C2, and so C3 votes
yes.
There are no downward paths from A3, B3, or D3 to C2, so
they all vote NO.
21. Swirlds Technical Report SWIRLDS-TR-2016-02 21
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
B4 strongly sees:
NO, NO, YES, NO
NO
NO
YES
NO
Since B4 strongly sees all of A3, B3, C3, and D3, it will
therefore collect votes from all of them.
The votes are NO, NO, YES, NO. So a supermajority is NO. So it
decides NO.
The election is over. C2 is not famous. Color it blue to show
that it is not famous.
22. Swirlds Technical Report SWIRLDS-TR-2016-02 22
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
There is a theorem that if any witness is able to “decide” yes or
no, then that is the result of the election, and it is guaranteed
that all other witnesses that decide are going to decide the
same way.
In this example, B4 was able to decide the election. If it had
collected votes that were more evenly split between YES and
NO, then it would have failed to decide. In that case, we can
consider D4. If D4 also fails to decide, then perhaps A4 or C4
might decide.
If none of the round-4 witnesses can decide, then each of
them will simply vote in accordance with the majority of the
votes they collected (voting YES in case of a tie). In that case, it
will be up to the round-5 witnesses to collect votes from the
round-4 witnesses. Perhaps the round-5 witnesses will be able
to decide.
23. Swirlds Technical Report SWIRLDS-TR-2016-02 23
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
The voting continues until it eventually reaches a round where
some witness can decide the election.
There is a theorem saying that the election will eventually end
(with probability one) as long as we add in a coin round every
10th round of voting.
In a coin round, collecting a supermajority causes a witness to
merely vote (not decide). And a non-supermajority causes it to
vote pseudorandomly, by using the middle bit of its own
signature as its vote.
24. Swirlds Technical Report SWIRLDS-TR-2016-02 24
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
6 more elections are run. They decide that A2, D2, A1, B1, C1,
and D1 are all famous.
In normal operation, most events are not witnesses, so there is
no election for most events. And most witnesses are declared
famous with an almost-unanimous vote in the first round of
voting. So most elections do not last very long.
Notice that in this example, we have now decided the fame of
every witness in round 2. Once a round has the fame decided
for all of its witnesses, it is possible to find the round received
and find the consensus timestamp for a new set of events.
Start by considering the gray event immediately below A2.
TECHNICAL DETAIL: If a member forks, they might have two famous witnesses in the same
round. In that case, neither of them are used further. Only the remaining ones (the “unique
famous witnesses”) are used to determine round received and consensus timestamp.
25. Swirlds Technical Report SWIRLDS-TR-2016-02 25
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
This event can be seen by every famous witness in round 2.
The red, green, and blue paths show how A2, B2, and D2,
respectively, can all see the black event.
This merely requires seeing, not strongly seeing.
This only requires seeing by the famous witnesses. It doesn’t
matter whether C2 can see the black event, because C2 is not
famous.
Since the black event is seen by all of the famous witnesses in
round 2 (but not in any earlier round), it is said to have a round
received of 2.
TECHNICAL DETAIL: we don’t need to limit ourselves to “seeing”. It is sufficient to use the
“ancestor” relationship instead. In other words, at this step, we don’t worry about forking.
26. Swirlds Technical Report SWIRLDS-TR-2016-02 26
A B C D
A2
A3
B1
B2
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
The consensus timestamp of the black event can be found as
follows.
Find the earliest event X by Alice that is an ancestor of A2 and
a descendent of the black event.
Similarly, find the earliest event Y by Bob that is an ancestor of
B2 and descendent of the black event. And similarly for event
Z by Dave.
Take the timestamps on the events X, Y, Z that were put in
those events by their creators. Sort all of the timestamps in
order. Take the middle one from the list (or the second of the
two middle ones, if there are an even number of them). This
median timestamp is the consensus timestamp for the black
event.
27. Swirlds Technical Report SWIRLDS-TR-2016-02 27
A B C D
A2
A3
B1
B3
B4
C1
C2
C3
D1
D2
D3
D4
A1
B2
Now consider the gray event below B2. It is seen by B2, but
not seen by A2 or D2. So it was not seen by all the famous
witnesses in round 2. So its received round will be later than
round 2. Leave it colored gray to indicate that it doesn’t yet
have a received round.