BLOCKCHAIN Technology & Applications #apiconf2018 BLOCKCHAIN - - PowerPoint PPT Presentation

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BLOCKCHAIN Technology & Applications #apiconf2018 BLOCKCHAIN - - PowerPoint PPT Presentation

Sep 16, 2023 471 likes •921 views

edoardo conte BLOCKCHAIN Technology & Applications #apiconf2018 BLOCKCHAIN Technology & Applications edoardo conte BLOCKCHAIN Technology & Applications #apiconf2018 BLOCKCHAIN Technology & Applications edoardo conte The

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BLOCKCHAIN

Technology&Applications #apiconf2018

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BLOCKCHAIN

Technology&Applications #apiconf2018

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BLOCKCHAIN Technology&Applications

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BLOCKCHAIN Technology&Applications

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The Blockchain

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BLOCKCHAIN Technology&Applications

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Distributed and decentralized

Normally, also Decentralized Distributed System

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BLOCKCHAIN Technology&Applications

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Public Blockchains

Possibility to design and deploy Smart Contracts Decentralized and distributed systems Everyone can join and maintain the blockchain

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BLOCKCHAIN Technology&Applications

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Consensus Algorithm

Determine the current builder Necessary to maintain a unique sequence of blocks!

Proof of Work Proof of Stake

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BLOCKCHAIN Technology&Applications

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Proof of Work Proof of Stake

Consensus Algorithm

Non-scalable algorithm Complexity really low Possibility to scale Very complex to implement Costless algorithm Great computational cost

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Blockchain Bridge Client

Distributed network

Read access link for the service Write access link for the service accessing the service accessing the service

BLOCKCHAIN Technology&Applications

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Secure data through Blockchains

Server with important data

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BLOCKCHAIN Technology&Applications

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Permissioned Blockchains

Different authorized entities work together to maintain a common service Standardized encryption and replication protocols Not completely decentralized

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BLOCKCHAIN Technology&Applications

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Hyperledger Fabric

Chaincode (Smart Contracts)

b

Customizable consensus algorithm

c

Full replication

  • f data

a

  • Crash Fault Tolerant
  • Byzantine Fault Tolerant

d State database in

CouchDB or LevelDB

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Structure

BLOCKCHAIN Technology&Applications

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Orderer

Peer Peer

Org1 Org2

CA1 CA2

Peer Peer Endorsing Peer Endorsing Peer

  • Ordering service
  • Consensus algorithm
  • Different organizations
  • Scalability
  • Certificate authorities
  • Endorsing peers
  • Execution of chaincode
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Transaction Flow

Endorsing Peer

Execute

Client

Endorsing Peer

BLOCKCHAIN Technology&Applications

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  • 1. Client sends a

transaction request

  • 2. Execution of Chaincode
  • 3. Sending the results back
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BLOCKCHAIN Technology&Applications

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Order

Client

Orderer

Transaction Flow

Endorsing Peer Endorsing Peer

  • 2. Ordering of

transactions

  • 1. Results sent

to the orderer

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BLOCKCHAIN Technology&Applications

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Validate Orderer

Endorsing Peer Endorsing Peer Peer Peer Peer

Transaction Flow

  • 1. Validation of each block
  • 2. If positive, it goes in

the ledger

Client

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BLOCKCHAIN Technology&Applications

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Orderer

Endorsing Peer Endorsing Peer Peer Peer Peer

Client

Transaction Flow

Validate

  • 1. Validation of each block
  • 2. If positive, it goes in

the ledger

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BLOCKCHAIN Technology&Applications

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Hyperledger Composer

Framework over Fabric

Logic

2

Access Control

3

Modeling language

1

  • Participant
  • Asset
  • Transaction
  • Event
  • Definition of the

transaction logic

  • Javascript code
  • Permissions
  • n resources
  • Complex

conditioned rules

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BLOCKCHAIN Technology&Applications

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Model.cto

/** * Definition of participants */ participant Person identified by username {

  • String username
  • String fullName
  • String email optional
  • String number optional

} participant Manufacturer identified by makerId {

  • String makerId
  • String name

}

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BLOCKCHAIN Technology&Applications

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Model.cto

/** * Definition of assets */ asset Vehicle identified by vin {

  • String vin
  • VehicleDetails vehicleDetails
  • -> Person owner

}

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BLOCKCHAIN Technology&Applications

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Model.cto

/** * Definition of transactions */ transaction ChangeOwner {

  • -> Vehicle vehicle
  • -> Person newOwner

} transaction SellVehicle {

  • VehicleDetails vehicleDetails
  • String vin
  • -> Person owner

}

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BLOCKCHAIN Technology&Applications

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Logic.js

/** * Sell vehicle transaction * @param {org.acme.vehicle.SellVehicle} arg * @transaction */ function onSellVehicle (arg) { }

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BLOCKCHAIN Technology&Applications

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Logic.js

const namespace = 'org.acme.vehicle'; // Extracting argument values let vehicleDetails = arg.vehicleDetails; const vin = arg.vin; const owner = arg.owner; const manufacturer = getCurrentParticipant(); vehicleDetails.manufacturer = manufacturer;

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BLOCKCHAIN Technology&Applications

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Logic.js

const factory = getFactory(); // Creating the vehicle let vehicle = factory.newResource(namespace, 'Vehicle', vin); vehicle.vehicleDetails = vehicleDetails; vehicle.owner = owner;

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BLOCKCHAIN Technology&Applications

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Logic.js

Update

// Updating the registry return getAssetRegistry(namespace + '.Vehicle’) .then ( assetRegistry => { return assetRegistry.add(vehicle); })

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BLOCKCHAIN Technology&Applications

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Logic.js

Update

// Updating the registry return getAssetRegistry(namespace + '.Vehicle’) .then ( assetRegistry => { return assetRegistry.add(vehicle); })

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BLOCKCHAIN Technology&Applications

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Permissions.acl

rule ManufReadsVehicle { description: "Manuf may read a car only if he made it" participant(manuf): "org.acme.vehicle.Manufacturer"

  • peration: READ

resource(vehicle): "org.acme.vehicle.Vehicle" condition: ( manuf.getIdentifier() == vehicle.vehicleDetails.manufacturer.getIdentifier() ) action: ALLOW }

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BLOCKCHAIN Technology&Applications

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Network Set Up

ORG1 ORG2 ORDERER

2 Peers 1 Peer Solo CA CA CouchDB CouchDB

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BLOCKCHAIN Technology&Applications

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Node 1

Orderer

Node 2

SQL DB

Node 4 Node 3

Org 1 Endorsing Peer CouchDB Org1 CA Org 1 Peer CouchDB NodeJs App

SQL DB

Org 2 Endorsing Peer CouchDB Org 2 CA NodeJs App

Client

  • Each element is a Docker container
  • Docker Swarm to communicate
  • API exposed by NodeJs
  • Composer SDK in NodeJs
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BLOCKCHAIN Technology&Applications

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Opening connection

const BusinessNetworkConnection = require('composer-client').BusinessNetworkConnection; module.exports = class Network { constructor(cardName) { this.cardName = cardName; this.connection = new BusinessNetworkConnection(); this.definition; this.namespace = 'org.acme.vehicle'; } async connect() { return this.definition = await this.connection.connect(this.cardName); }

Blockchain

connection

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BLOCKCHAIN Technology&Applications

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Submit Transaction

Blockchain

const factory = this.definition.getFactory(); // Submit transaction const tx = factory.newTransaction(this.namespace, 'SellVehicle’); tx.vehicleDetails = vehicleDetalils; tx.vin = vin; tx.owner = factory.newRelationship(this.namespace, 'Person', ownerId); return await this.connection.submitTransaction(tx);

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BLOCKCHAIN Technology&Applications

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Submit Transaction

Blockchain

const factory = this.definition.getFactory(); // Submit transaction const tx = factory.newTransaction(this.namespace, 'SellVehicle’); tx.vehicleDetails = vehicleDetalils; tx.vin = vin; tx.owner = factory.newRelationship(this.namespace, 'Person', ownerId); return await this.connection.submitTransaction(tx);

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BLOCKCHAIN Technology&Applications

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Repositories

https://bitbucket.org/hugrave/composer-vehicle-network/ https://bitbucket.org/hugrave/blockchain_server/

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BLOCKCHAIN Technology&Applications

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Performance evaluation

Benchmark done with 1000 assets GET —> ~ 10 seconds PUT, DELETE —> ~ 100 SECONDS

Improvement through Cloud deployment Not real-time applications

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BLOCKCHAIN Technology&Applications

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PRIVACY

Rich conditioned language

Permissions in Hyperledger Composer

BUT…

The ledger remains in plain-text!

/var/hyperledger/production/ledgersData/chains/chains/{channel_name}/

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BLOCKCHAIN Technology&Applications

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DO NOT DESPAIR!

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BLOCKCHAIN Technology&Applications

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Peer 1 Peer 2 Peer 3

Fabric Channels

Channel 1 Channel 2 Channel 3

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BLOCKCHAIN Technology&Applications

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Peer 1 Peer 2 Peer 3

Fabric Channels

Channel 1 Channel 2 Channel 3 Channel 3 Peer 1 joined channel 3 Peer3 joined channel 2 Channel 2

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BLOCKCHAIN Technology&Applications

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Off-chain encryption decryption

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BLOCKCHAIN Technology&Applications

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Off-chain encryption decryption

Client1 D B Data inserted in the blockchain is encrypted Decryption is possible only with the keys NodeJs Org1

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Off-chain encryption decryption

D B

BLOCKCHAIN Technology&Applications

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Client1 Data inserted in the blockchain is encrypted Decryption is possible only with the keys NodeJs Org1

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BLOCKCHAIN Technology&Applications

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Off-chain encryption decryption

Client1 Client2 D B D B

Authorization is a secure keys exchange

NodeJs Org1 NodeJs Org2

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BLOCKCHAIN Technology&Applications

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Off-chain encryption decryption

Client1 Client2 D B D B NodeJs Org1 NodeJs Org2

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BLOCKCHAIN Technology&Applications

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CONCLUSIONS

They can rely on a robust architecture

b

Each company checks directly wether the structure

  • f the network is respected

c

Companies may share their data securely

a d Performances may be improved

through Cloud deployment or container optimizations

e Privacy must be taken into

account in order to separate data

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E ndless Possibilities

Thank you for the attention

Edoardo Conte

BLOCKCHAIN Technology&Applications

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