6. Problem
@horeaporutiu
Fisherman Processor Distributor Plate
• There are so many parties involved
• Different parties have different incentives
• Hard to trust that your fish is actually
organic
Traceability of fish from ocean to plate
8. What is blockchain?
• Blockchain - a continuously growing list of
records, called blocks, which are linked and
secured using cryptography.
• A digital ledger that is replicated across all
network participants
@horeaporutiu
• Network participants collaborate to maintain the
ledger
9. Types of blockchain
Public Private
@horeaporutiu
• Open to anyone
• Large computational
requirement
• Participants
incentivized with
cryptocurrency
• Bitcoin
• Need permission to
join the network
• Walmart solution
• Less computational
power required
• Cryptocurrency is
typically not involved
• Transactions can be
kept private
10. Identify blockchain use-cases
• If data is used only by one organization, then it’s
most likely not a good use of blockchain
@horeaporutiu
Distributed Ledger
Distributed
Smart ContractsImmutable
Share data across
multiple companies
Permanent record of
transactions
No central point of
ownership
Business rules visible
to all members
11. Hyperledger
• A collaborative effort created to
advance cross-industry
blockchain tech for business
• Hyperledger is an umbrella – 5 frameworks, 4
tools under Hyperledger
@horeaporutiu
• Announced in 2015, now over
180 members
12. Hyperledger Fabric
• An implementation of blockchain technology used
as a foundation for developing blockchain
applications
@horeaporutiu
• V1.0 released July 2017
• 27 organizations, 159 developers
13. Hyperledger: Writing Smart Contracts
• Either as native chain code – using Go, Java, or
Node.js
@horeaporutiu
• Hyperledger Composer – Easy way to write smart
contracts w/ JavaScript
https://medium.com/@olivier.mathurin/build-a-blockchain-prototype-in-minutes-with-hyperledger-
composer-e132e17c98c7
15. Generate network archive - .bna file
@horeaporutiu
Model File .cto
Access Control
Script File .js
Assets, participants,
and transactions
Transaction functions
Access Control Rules
Business Network
Packaged business
network definition
Archive .bna
.acl
networkadmin.card
Credentials for admin
of the network
16. Writing your first model file (.cto)
@horeaporutiu
1. namespace
2. Participants
3. Assets
4. Transactions
5. Events
Need to define the following:
🙋🏽♀️🙋🏽♂️
🏽
💰
‼️
🔡
Need more help? Check this tutorial:
https://www.skcript.com/svr/writing-your-first-business-model-in-
hyperledger-composer/
before we get started, by a show of hands, how many of you know about blockchain?
How many have taken a course or been to class on blockchain?
How many have developed applications using blockchain technoloies?
Well no matter your skill level, and familiarity with blockchain, I think you will be able to learn something useful from this session.
Today, I want to take you through a journey with blockchain. I’ll go over the main concepts of blockchain, and more importantly, when blockchain is a suitable solution for your problem. I’ll talk about Hyperledger, a popular open source technology for building blockchain applications and then I’ll go into a demo of how to start building blockchain apps with Hyperledger, and then go into Q/A.
before we get started, by a show of hands, how many of you know about blockchain?
How many have taken a course or been to class on blockchain?
How many have developed applications using blockchain technoloies?
Well no matter your skill level, and familiarity with blockchain, I think you will be able to learn something useful from this session.
Today, I want to take you through a journey with blockchain. I’ll go over the main concepts of blockchain, and more importantly, when blockchain is a suitable solution for your problem. I’ll talk about Hyperledger, a popular open source technology for building blockchain applications and then I’ll go into a demo of how to start building blockchain apps with Hyperledger, and then go into Q/A.
So earlier I talked about the food industry and how they could benefit from a blockchain solution for their supply chain.
But to be fair, blockchain doesn’t have to be limited to the supply chain
Any industry where goods and services change hands has this problem
Existing business network: when their ledger disagree, need to go to the court…no agreement there
Everyone has to maintain their own private ledger, and is vulnerable for this problem too
The problem here becomes, how do I trust that this fish is organic? I mean, the fish changes hands from fisherman, to processor, to distributer, to the market. What if someone along the way made a mistake?
Then I’m paying more for the same quality
How do I trust that this fish is actually wild, and not just marketed as so?
So here we see that in a typical solution, there are multiple parties that are working together in a businessss network. We have The bank, the auditor, the the farmer, the processor, the distributor, and the retailer
Blockchain is a trusted distributed ledger
Way for business to share data when they don’t necessarily trust each other
Solve this problem by providing a single source of truth by the use of a shared and replicated ledger
Blockchain tech ensures that everyone has the same copy of the ledger
4 key aspects
Consensus: when anyone wants to add a change to the blockchain, a set of participants need to agree that that transaction has occurred. So if participant A does a trade with participant B, then maybe the bank and the auditor might get involved and sign off on that. Blockchain tech will provide WHO has to endorse the transactions before they get added to the ledger
Provenance: can show history of where you caught your fish
Immutable: can’t go back and change the ledger. If you try and change your copy of the ledger, since the ledger is replicated, none of the other ledgers will agree, easy to see that you tampered with ledger
Finality: ledger is the simple source of truth. can’t disagree with blockchain since everyone agrees with the updates…it is the single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
Explain private vs public, and what each means
What is a public blockchian, is private hyperledger a blockchain implementation?
Usually, the first sign that blockchain is not right for your solution is if you are not dealing with multiple organizations. On the other hand, if you need permanent record of transactions and lack trust between the different organizations, then blockchain might be a possible solution for your problem.
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth
So here is the mandatory definition slide
The main points here is that blockchain is a list of records, which enables participants to transact with each over a network with TRUST.
also, the ledger is replicated across all participants, so everyone in the network has a single source of truth