Drupal and the Ethereum Blockchain

#DrupalEthereum @digitaldonkey09

About me

• about 20 years ​​web development  
• 10+ years with Drupal
• 2 years in Ethereum 
• Developer at ConsenSys 

@digitaldonkey09

Overview

• What is a Blockchain
• Ethereum ecosystem
• Blockchain components
• Drupal Ethereum Architecture & outlook

Blockchain

a simplified introduction

• Banks improve interbank settlement
• Governments exploring paperless e-government and registries
• Healthcare/Insurance - sharing evidence, verified prescriptions
• Law - investigating the legal side of "smart contracts"
• Energy - incentivizing energy efficiency and trading
• IoT - Internet of things, sensors, appliances
• NGOs - transparency in international aid & outcomes

Blockchain's promises

"Sharing Economy" of
Uber, Airbnb, Spotify

Centralized User Data,
Facebook, Google

Reduce
Middlemen

Self-sovereign
user identity

Internet of
Information

Don Tapscott: "How the Blockchain is changing money and business"

Internet of
Value & Trust

Imagine the Blockchain as a
"Decentralized Consensus Database"

"0xd62e7da1d30af2abed70f0ec677fefe0a0db5774  owns 5 Bitcoin"

agree

agree

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Ethereum is an open-source, public,
     blockchain-based distributed computing
     platform featuring smart contract functionality.

Ethereum Blockchain

Decentralized
P2P consensus

No central authority
 

Any state change requires a cryptographically signed Transaction

Global ledger with immutable records

Programmable money:
Smart Contracts

Data in Blockchain is public.

• Interpretable when knowing the contract ABI (Application Binary Interface).

"Writing to Blockchain" requires:

• the private key of the from address to sign the transaction
• some fee for computation/data storage in Ether (public chain)

time

Smart Contracts in Ethereum

Contract crowdFound
 if (account_balance) > $10,000
   move account_balance to founded_account
 else
   move donation_account to original_donor

(pseudocode)

Smart contracts are applications with a state stored in the blockchain

• can run automatically when certain conditions are met
• Addressable, can handle money / escrow, Turing-complete
• Crowd founding as a Smart Contract:

• Public and private keys like in PGP
• Signing requires user interaction (if you don't host the keys      )
• Ethereum Address is derived from the private key
• Signing Transactions (means also deploy code)
• Signing text (Signatures)
• Encryption (Similar to PGP)

Transaction Signers

• Mist browser   (Full Blockchain)
• Metamask   (Browser extension)
  Coming up: MetaMascara (browser independent)
• uPort   (Identity provider)
• MyEthereumWallet   (Online or Offline browser)
• Jaxx (Mobile App & Browser extension)
• Hardware based signing (Ledger wallet)

Ethereum wallets, Identity providers ... 

Ethereum Signup

• Challenge/response authentication
• No Blockchain interaction - no fee
  Just Elliptic Curve cryptography

Ethereum user connector

• Smart contract with registry
• May be changed to a paywall
• Transaction require little payment in Ether

Architecture challenges

Ethereum ecosystem summary

• Public Ethereum Blockchain or
  private/consortium chains can be used
• Immutable audit trails for data saved in blockchain
• Smart contract code is deployed to the blockchain
• Ether is the currency in Ethereum:
    Anti-spam and incentive to run the public network        

Challenges

• Still evolving (Solidity 0.4.17)
• Improve Ethereum TX trough-put                              
• TX-Signers / Cross-browser availability of end-user tools
• Light clients (Chain size is currently about 280GB)
  https://etherscan.io/chart/chaindatasizefull

Drupal Ethereum Module

• Founded and abandoned in 2014
• New approach started 2016
• Ethereum PHP library abstraction
• POC for signup with registry
• Currently:
  Focus on infrastructure modules
• Later:
  maybe out-of-the-box like
  http://bit.ly/drupalvoting

Current web

Ideal decentralization

How to connect Drupal and Ethereum?

Semi-decentralization

Client side signing using Transaction-signers

Server just pulls data

(no private key on Server)

Mapping Ethereum to Drupal

Servers (Ethereum-nodes)
List Servers, gather information (Server Entity)


Accounts/Ethereum Addresses
Map Accounts to Drupal Accounts
➡ Identity for known user group

          Transactions

• Read (own contracts/known ABI)
• ​Log TX based on Contract interaction
• Process TX data in Drupal

          Smart Contracts

• Manage deploy as Drupal Admin
• Provide ABI to process data in Drupal
• Let Users interact (→ TX data)

Infrastructure modules

State and Roadmap

Current: POC

• Identity: "User connector" connects Ethereum accounts and user profiles via registry contract
  See Video https://youtu.be/Y5Sa7QtpXSE 
• Identity: "Signup" (currently in github only)
  https://github.com/digitaldonkey/docker-drupal-ethereum
   

Finalizing infrastructure modules (MVP)

• PHP library lacks support of complex data types
• Make Transaction-signers pluggable & add more 
• Contract management & deployment from Drupal backend            
• Server Entities

Drupal Ethereum module

Why should Drupal care about Blockchain?

• Blockchain provides adds a new trust layer to the internet
• Drupal can provide Identity in context of limited user groups
• Implement enterprise level workflows, required for Document signing, Peer-to-peer platforms, Asset tracking ...
• Explore new ways of NGO founding, budgeting, voting.

• Join BOF tomorrow: Wed 14:15 Galerie 7-8
• Evaluate use cases, join discussion
  https://groups.drupal.org/ethereum
• Tweet about #DrupalEthereum

thorsten.krug@consensys.net
       @digitaldonkey09

The development of Drupal Ethereum Module
Has been sponsored by ConsenSys
       @ConsenSys

https://consensys.net

slides.com/digitaldonkey/drupal-ethereum-2