Bitcoin Protocols 1.0 and 2.0 Explained in the Series: Blockchain: The Information Technology of the Future

Bitcoin Protocols 1.0 and 2.0 Explained
October 11, 2014
Bitcoin Meetup
Slides: http://slideshare.net/LaBlogga
Blockchain: The Information
Technology of the Future
Melanie Swan
melanie@BlockchainStudies.org
www.BlockchainStudies.org

What is the Blockchain?
October 11, 2014
Blockchain Technology
1
We should think about the blockchain as another class of
thing like the Internet – a comprehensive information
technology with tiered technical levels and multiple
classes of applications for any form of asset registry,
inventory, and exchange, including every area of finance,
economics, and money; hard assets (physical property);
and intangible assets (votes, ideas, reputation, intention,
health data, information, etc.). In fact the blockchain
concept is even more, it is a new organizing paradigm.
– Melanie Swan, Founder, Institute for Blockchain Studies

New VC investment cycle: Blockchain Tech
October 11, 2014
“The blockchain is the core innovation,”
Marc Andreessen, CoinSummit (Mar 2014)
“We want a whole sequence of companies: digital
title, digital media assets, digital stocks and bonds,
digital crowdfunding, digital insurance. If you have
online trust like the blockchain provides, you can
reinvent field after field after field.”
2
http://www.bloomberg.com/news/2014-03-28/bitcoin-2-0-shows-technology-evolving-beyond-use-as-money.html

About Melanie Swan
Traditional Background
October 11, 2014
3
New market startups:
Grouppurchase
Prediction Markets
Quantitative Methods
Virtual World Valuation Blockchain Futures
http://www.slideshare.net/lablogga/singularity-university-live-prediction-markets-simulation-big-data-indicators
http://www.slideshare.net/lablogga/virtual-worlds-economy

Agenda for Blockchain Futures
 Blockchain Industry Status
 Bitcoin Protocol 1.0
 Bitcoin 2.0 Protocols
 Bitcoin 2.0 Platform: Ethereum
 Appendix: Bitcoin Basics
October 11, 2014
4
Based on information synthesized from Internet resources including cryptocurrency expert Andreas
M. Antonopoulos and Ethereum project members (Vitalik Buterin, Gavin Wood, Stephan Tual)

What is Bitcoin? Terminology confusion
 The term Bitcoin is used to refer to 3 things:
1. The underlying technology concept/platform
2. The protocol for using this technology platform
3. The currency for transactions using this protocol
 It is as if Paypal called the Internet Paypal, upon which
the Paypal protocol was run to transfer Paypal currency
 Instead, more appropriate terminology is
1. Blockchain technology: the underlying technology platform
(decentralized digital transaction ledger; an information
technology akin as a ‘class of thing’ to the Internet)
2. Bitcoin protocol: transaction system to move value between
parties without third party interaction
3. Bitcoin currency (denoted as btc): the bitcoin coins
October 11, 2014
5

What is the Blockchain?
October 11, 2014
6
 Decentralized transaction database shared by all
network nodes, owned, updated, and monitored by
everyone, controlled by no one
 Like a giant interactive spreadsheet everyone has access to and
updates to confirm that the digital transactions are unique
 Solution to the double-spend problem
 Previously, a centralized third party had to issue and reconcile
digital cash transactions to prevent the electronic cash from
being spent multiple times (easy to copy digital assets)
 BitTorrent P2P file-sharing technology plus public key
cryptography combined to make a new form of currency
 Name blockchain: literally transactions grouped into
blocks and posted sequentially in a chain to the ledger

Blockchain explorer allows viewing of latest
transactions posting to the Ledger
October 11, 2014
7

Specific Transaction Detail
October 11, 2014
8

Proposed Blockchain Uses
 Decentralized transaction ledger could be used to encode
and confirm/transfer all property
 Financial
 Currency, Stock, Private Equity, Bonds, Derivatives, Crowdfunding
 Public Records
 Land Titles, Vehicle Registries, Business Licenses, Passports,
Voter IDs, Death Certificates, Proof of Insurance
 Private Records
 Contracts, Signatures, Wills, Trusts, Escrows
 Physical Asset Keys
 Home, Hotel Rooms, Rental Cars, Car Keys
 Intangibles: Patents, Trademarks, Reservations, Domain Names
October 11, 2014
9
http://ledracapital.com/blog/2014/3/11/bitcoin-series-24-the-mega-master-blockchain-
list

Blockchain Industry Status
 Bitcoin protocol ossifying (like IPv4: victory by diffusion)
 To be stabilized within 2 years for 30 years
 Harder to make any changes: 6 constituencies for consensus
1. Miners (independents, pools, ASICs)
2. Merchant processing gateways
3. Web wallet companies (Blockchain.info)
4. Exchanges (Coinbase, Bitstamp)
5. Users/consumers
6. Hardware manufacturers (TREZOR)
TREZOR
hardware wallet
 Impossible for new alt.coins to get network effect traction
 Bitcoin developer focus
 BIP0032 spec
 Hierarchical deterministic wallet trees, sidechains (btc-pegged)
October 11, 2014
10

Bitcoin code on github
October 11, 2014
https://github.com/bitcoin/bitcoin/graphs/contributors 11

Bitcoin Protocol 1.0 and 2.0
 Bitcoin 1.0: democratization of money, payments
 Bitcoin 2.0: democratization of markets (‘web -> Amzn’)
 Not just currency, contracts, property, savings accounts
 Financial instruments: stock, bonds, derivatives
 Decentralized exchanges
 Decentralized applications (DAOs)
 Decentralized companies (DACs)
 1.0 protocol: various technical limitations
 Multi-signature, blockchain bloat, processing
 Irreversible transactions, one asset per token
 Anonymity, fungibility, scalability, vulnerability (51% attacks)
 Robust Turing-complete protocol system, scripting language
October 11, 2014
12

Bitcoin 2.0 Protocol Projects/Companies
 Similar fungible functionality, application-specific foci
 Bitcoin overlay (‘HTTP/HTML/SMTP to Bitcoin’s TCP/IP’)
 Colored Coins: issue your own currency on the bitcoin network
(by adding metadata to Bitcoin transaction)
 Counterparty: a decentralized exchange between alt.currencies
 Mastercoin: financial derivatives
 ZeroCoin, NXT
 Alt.chains: Separate blockchains (‘new TCP/IP’)
 Namecoin: decentralized domain name registry
 Ripple: gateway, payment, exchange, remittance network
 BitShares: decentralized crypto-equity share exchange
 Ethereum: decentralized Turing-complete platform
October 11, 2014
13

Bitcoin/Blockchain Sector Funding (as of Oct 2014)
 $300 million venture capital
 $30 million crowdfunding
 https://bitcoinstarter.com/, http://coinfunder.com/
October 11, 2014
14
http://www.coindesk.com/will-bitcoin-venture-capital-investment-reach-300m-2014/
http://en.wikipedia.org/wiki/List_of_highest_funded_crowdfunding_projects

Bitcoin 2.0 Protocols: Difference Parameters
 How plugs into Bitcoin ecosystem
 Own blockchain or overlay to bitcoin
 Functions of own currency (issue and retire assets)
 Money supply
 Fixed, growth-specified (inflationary, deflationary)
 Mined, pre-mined
 Currency/tokens: native, fiat, other cryptocurrency
 How blocks are created (transactions fees and
rewards)
 Consensus, proof-of-work, proof-of-stake, hybrid,
proof-of-burn; code feature bounties
 Issuance (crowdfunding, venture capital)
October 11, 2014
Source: Piotr Piasecki 15

$18.4m USD Ethereum Fundraising 7/2014
 Initial Sale
 (Sliding) 2,000 ether to 1 bitcoin or $620
 60m Ether (ETH) sold ($1 USD ~ 3.25 ETH)
 Dev offices in Berlin (expanding to ~20)
 Ongoing Macroeconomic Policy
 Ether has build-in increase of overall money
supply at fixed rate
 40% of the amount raised in the fundraiser will
be the annual increase in money supply
 Ether subunits
 Finney (10-3), szabo (10-6), shannon (10-9),
babbage (10-12)
October 11, 2014
Vitalik Buterin, Creator
Gavin Wood, Architect
16
Stephan Tual, CCO
http://www.businessinsider.com/ethereum-launches-ether-2014-7

The Ethereum Project
 Complete Step 3 of Satoshi Nakamoto’s original plan
1. (The blockchain) Decentralized database, put assets into a
transparent ledger, everyone has a copy
2. (The bitcoin protocol) Transaction system to move value
between parties without third party interaction
3. Robust scripting system; instead of just sending currency, send
contracts, smart property; requires Turing completeness
 ‘General-purpose’ cryptocurrency network
 A decentralized publishing platform featuring stateful
user-created digital contracts and a Turing-complete
contract programming language
 Chain implementation & contracts with shared mining
October 11, 2014
17

Smart Contracts: Programmable Money
 Multisignature (multiparty) escrows (~Bitrated 2.0)
 Financial exchanges
 Savings Accounts
 Domain name registries
 Self-enforcing contracts and agreements
 Crowdfunding platforms, Prediction markets
 Smart property
 Intellectual property
 Voting systems
 Company governance
 Nationstate constitution and bill of rights
October 11, 2014
18

Write your own Smart Contracts
October 11, 2014
19 http://forum.ethereum.org/discussion/1402/how-to-get-started-your-first-dapp-under-one-hour

Example: Smart Property
 Instead of trading coin, shares, trade/buy-sell assets
 Encode asset to the blockchain via unique key
 Trade cars on the blockchain through a decentralized
exchange
 Entire used auto market trades via blockchain
October 11, 2014
20
 Blockchain becomes
an inventory,
tracking, and
exchange mechanism
for all hard assets

Ethererum Browser ‘Mist’ Mock-up
October 11, 2014
21 http://forum.ethereum.org/discussion/1402/how-to-get-started-your-first-dapp-under-one-hour

The key benefit of Ethereum for the automated-economy is that
it is a Turing-complete VM
Ethereum Virtual Machine (EVM)
October 11, 2014
22
 The Ethereum blockchain is…
 A blockchain with a built-in programming language
 The decentralized, massively replicated database in which the
current state of all accounts is stored
 A consensus-based globally executed virtual machine
 The Ethereum Virtual Machine (EVM) handles internal
state and computation
 Large decentralized computer with millions of account objects
 Each account object
 Has its own internal code
 Contains a 32-byte key/value database called storage
 Can call or send messages to other objects
https://github.com/ethereum/wiki/wiki/Ethereum-Development-Tutorial

Tech Specs
Accounts stored in a Patricia tree (like a Merkle tree)
 A root hash refers to the entire tree;
tree contents cannot be modified
without changing the root hash
 A miner produces a new block each
minute with the latest transactions and
the root hash of the Patricia tree
representing the new state
 4-tuple stored per account
 [account_nonce, ether_balance, code_hash, storage_root]
 account_nonce: the number of transactions sent from the account
(kept to prevent replay attacks)
 ether_balance: the balance of the account
 code_hash: the hash of the code if the account is a contract
 storage_root: the root of another Patricia tree with the storage data
October 11, 2014
23

Ethereum Contract Processing
October 11, 2014
24
 Two account object types
 Contract
 EOA (externally owned account)
 Contract receives a message and runs the code
 Ability to read/write to its own internal storage
 Read the storage of the received message
 Send messages to other contracts, and to itself
 The contract is the code that executes the contract
 Contract can interact with the world outside the EVM
 EOA (externally owned account) messages the contract
 Transaction is sent signed by the EOA’s private key
 Advanced: SchellingCoin Universal Data Feed for derivatives
(minimal trust, two-step commitment protocol per round)
https://blog.ethereum.org/2014/03/28/schellingcoin-a-minimal-trust-universal-data-feed/

Ethereum Contract Example
 GavCoin is stored as
entries in the GavCoin
contract's database
 The bet contract sees the
temperature and messages
the GavCoin contract to
payout (object autonomy)
October 11, 2014
25
 GavCoin weather bet between Bob and Alice
 Automated EVM communications
 Heterogeneous user security preferences
 A transaction is sent, triggering forwarding contract
and EAO messaging
EAO (externally owned account)

EVM Operation / “Gas” Fees
 Ethereum consensus model
 Each operation executed in the EVM is simultaneously executed
by every full node
 Benefit: any contract on the EVM can call any other contract at
almost zero cost
 Cost: computational steps on the EVM are very expensive
 Transaction fee and block operation limit
 The Ethereum protocol charges a market-based fee in ether per
computational step (prevent deliberate attacks and abuse)
 Floating limit on the number of operations contained in a block
 Even miners who can afford to include transactions at close to
no cost are forced to charge a fee commensurate with the cost of
the transaction to the entire network
October 11, 2014
26

Smart Contract-DOA/DAC Progression
 Smart Contract
 Transaction protocol that executes the terms of a contract
 Smart property: property whose ownership is controlled via the
blockchain using contracts (examples: cars, phones, houses)
 Đapp (Decentralized Application)
 Contract plus graphical interface for contract execution
 JavaScript API ‘eth object’ interacts with Ethereum blockchain
 DAO (Decentralized Autonomous Organization)
 Self-enforcing smart contract (group of contracts) on a
cryptographic blockchain, multiparty complexity
 (Like remittances) avoid local business jurisdictional costs
 Own Ethereum address (key) and balance, send and receive
transactions, EtherScript scripts can modify their own code
October 11, 2014
27
http://www.slideshare.net/mids106/ethereum-decentralized-autonomous-organizations
Egalitarian DAO contract explained: https://www.youtube.com/watch?v=Q_gxDytSvuY

Decentralized Autonomous Corporations
 DACs, automated markets, and tradenets
 Fully-autonomous business entity
 Autonomous property, example: self-owned, self-driving car
 Example:
Vehicles use the tradenet to find
customers and bid for road space
 Storj.io (decentralized cloud storage) - Gregory Maxwell
 MetaDisk: upload your data to the Storj network
 DriveShare: earn money by being a part of the Storj network
 Doesn’t work on bitcoin due to scripting language limitations
October 11, 2014
28
http://www.slideshare.net/mikehearn/future-of-money-26663148, http://storj.io/
http://bitcoinmagazine.com/7050/bootstrapping-a-decentralized-autonomous-corporation-part-i/

Tech Specs
State Machine, Languages, and Code
 Current Release
 Proof of concept build - PoC5, GitHub release on July 22, 2014
with the launch of the Ether pre-sale
 EVM computation via a stack-based bytecode language
 Bitcoin Script, traditional assembly, and Lisp
 A program in EVM is a sequence of opcodes
 Contract programming with high-level languages
 LLL, serpent, Mutan compiles into EVM
 Create contracts by sending the transaction containing the EVM
bytecode
 One-click installation for everything (like mobile apps)
 Ecosystem Plug-and-play: Wallet, Open Transactions, Ripple
October 11, 2014
29

Classes of Ethereum Applications
October 11, 2014
30
 Finance and Economics
 BitCloud (decentralized escrow), OpenLibernet (open comms)
 Debt market, futures (derivatives), savings
 Voting (Futarchy, Liquid Democracy)
 Resource exchange: eBay, Amazon, Uber, AirBnB
 Functions: authentication, validation, escrow, delivery
 P2P Package Courier Service (notified as you leave location)
 Real-time cost-based data center storage swapping
 Loyalty, everyone’s own currency: JefCoin
 Automated markets, tradenets
 Economics: transactions/contracts pay-on-board network Ether
 GBI (Guaranteed Basic Income) – Switzerland freicoin

One use for Ethereum
Blockchain Genomics
October 11, 2014
31
 Jurisdictional regulation prevents
individuals from having access to
their own genetic data
http://genomesunzipped.org/2011/03/people-have-a-right-to-access-their-own-genetic-
information.php

Alt.apps: Blockchain Health
 Using blockchain tech for health-related applications
1. Personal Health Record Storage
 Personal health records stored and administered via blockchain
 Users key-permission doctors and other parties into records
2. Health Research Commons
 Aggregated personal medical records, quantified self data
commons (DNA.bits)
3. Health Document Notary Services
 Proof-of-insurance, test results, prescriptions, status, condition,
treatment, physician referrals
4. Doctor Vendor RFP Services
 (Like Uber drivers) doctors and health practices bid to supply
medical services; automated bidding via tradenets
October 11, 2014
32
http://futurememes.blogspot.fr/2014/09/blockchain-health-remunerative-health.html

Demurrage Blockchain Health
 Demurrage currency: built-in mechanism for
spend/action-taking
 Freicoin: Switzerland GBI (Guaranteed Basic Income)
 GBHA (Guaranteed Basic Health Initiative): paid out and payable
in HealthCoin; HSA (Health Savings Account) 2.0
 Fitbit and smartwatch are demurrage health currencies
 Health itself as a demurrage currency, a continually
auto-redistributing commodity among synapses, cells,
humans; body and brain as a DAO/DAC AI
 Concept: demurrage resource-allocation + Đapp
 Automatic redistribution of any commodity within a system (brain or mindfile
(potentiation, optogenetic stimulation)), body (‘health’ (oxygen, waste removal
nanobots, circulating lab-on-chips)), work team (ideas), society (liberty)
October 11, 2014
33
Fitbit is a demurrage (action-inciting) health currency

Alt.apps: Blockchain Futures
 Any venue for decentralized contracts (Đapp)
 ‘Bitcoin MOOCs’ (‘Kickstarter for literacy’)
 Like remittances, blockchain-improved aid, microcredit,
development economics 2.0
 Write Ethereum Literacy Contracts to emerging market peers
 Reading, Technical, Agricultural, Vocational Literacy
 New implementation of education in the blockchain
 Blockchains as a public good
 Wikileaks, ICANN, Wikipedia, Genomics
 Uplifted to cloud from jurisdiction
October 11, 2014
34

Alt.apps: Blockchain Futures
 Community supercomputing time
 Blockchain tech as resource allocation for science efforts
 Funding markets like crypto-equity and crowdfunding for any
resource
 Reputation systems (OpenBazaar), insurance
(SchellingQuake), Key recovery (wallet key protection)
 Blockchain GAAP: valuation, amortization, retirement
 Intangible asset encoding, tracking, and trade
 Attention, intention, reputation, health, ideas
 Cryptoledger, financial cryptography, consensus-based
ledger: revolutionizing concept for traditional institutions
and startups in finance and beyond
October 11, 2014
35

Tech Specs
Ethereum: Vitalik 9/14 Silicon Valley update
 Key progress: proof of stake
 Custody mining, hybrid proof-of-stake proof-of-work,
Slasher, TenderMint, dbus
 Decentralized application architecture
 Ethereum: blockchain, account registry
 Whisper: decentralized messaging (decentralized Twitter)
 MadeSafe, Swarm: decentralized off-chain storage (images)
 NameCoin, KeyID.info, Open Libernet: decentralized DNS,
network messaging
 Dev priorities: fully decentralized Internet Đapps
 Proof of Concept 6 (?) – consensus algorithm SchellingCoin
(POW-POS); UI; mobile client; DevTools
 Ethereum 1.0 core, optimization, security, virtual machine
October 11, 2014
36

Tech Specs
Ethereum JavaScript API: eth object
 Ethereum contract execution interface is implemented as
an HTML/CSS/JS webpage
 JavaScript API, eth object interacts with the Ethereum
blockchain, JavaScript API components:
 eth.transact(from, ethervalue, to, data, gaslimit, gasprice) - sends a transaction to the desired
address from the desired address (note: from must be a private key and to must be an
address in hex form) with the desired parameters
 (string).pad(n) - converts a number, encoded as a string, to binary form n bytes long
 eth.gasPrice - returns the current gas price
 eth.secretToAddress(key) - converts a private key into an address
 eth.storageAt(acct, index) - returns the desired account's storage entry at the desired index
 eth.key - the user's private key
 eth.watch(acct, index, f) - calls f when the given storage entry of the given account changes
 Required: Ethereum client (not regular web browser)
 JavaScript API example: see source of link below
October 11, 2014
37

Tech Specs
Ethereum Code
 PoC5 (Proof of Concept #5) (stable):
 AlethZero (C++)
 Ethereal (Go)
 pyeth (Python)
 PoC6 (experimental):
 https://github.com/ethereum/cpp-ethereum/
 https://github.com/ethereum/go-ethereum
 https://github.com/ethereum/pyethereum
October 11, 2014
https://github.com/ethereum/wiki/wiki 38

Resources
 Coindesk (Bloomberg of Bitcoin)
 http://www.coindesk.com
 Let’s Talk Bitcoin podcast
 http://letstalkbitcoin.com/
 Industry experts
 ‘Crypto-guru’ Andreas Antonopoulos http://antonopoulos.com
 Economist Susan Athey (Stanford, Microsoft, Ripple)
http://www.coindesk.com/professor-susan-athey-people-use-bitcoin-intrinsic-value/
 Overview News Articles
 SATOSHI'S REVOLUTION: How The Creator Of Bitcoin May Have
Stumbled Onto Something Much, Much Bigger
http://www.businessinsider.com/the-future-of-the-blockchain-2014-4
 Future of Bitcoin & Math-Based Digital Currencies
http://www.youtube.com/watch?v=Yg1JnbIS60g
October 11, 2014
39

Resources
 Ethereum
 http://www.reddit.com/r/ethereum/
 https://www.youtube.com/user/EtherCasts
 https://github.com/ethereum/wiki/wiki
 Ethereum Development Tutorial
 White paper, Yellow Paper (http://gavwood.com/Paper.pdf)
 Bitcoin Original White Paper
 Satoshi Nakamoto’s design for the blockchain (2008)
 https://bitcoin.org/bitcoin.pdf
October 11, 2014
40

Image credit: M. Ghezel
October 11, 2014
Bitcoin Meetup
Slides: http://slideshare.net/LaBlogga
Blockchain: The Information
Technology of the Future
Melanie Swan
melanie@BlockchainStudies.org
www.BlockchainStudies.org
Thank You! Questions?

Appendix: Bitcoin/Blockchain Background
 The New Economy…
October 11, 2014
42
http://www.google.com/trends/explore#q=bitcoin

Cryptocurrency Market Cap Tracking
October 11, 2014
43
https://coinmarketcap.com/

What is Bitcoin?
 Digital currency, payments system, decentralized ledger
 History: by combining BitTorrent technology (peer-to-peer
file sharing) and public key cryptography a new
form of currency was made possible
 Arose as a solution to the double-spend problem
 Prior to bitcoin and the blockchain concept, a centralized third
party had to issue and reconcile digital cash transactions to
prevent the digital cash from being spent multiple times (digital
cash, like an image attached to an email, can be copied infinite
times like any digital cash)
 Implication: any transaction on the Web can be
decentralized and stripped of a controlling authority
October 11, 2014
44
http://codinginmysleep.com/bitcoin-mining-in-plain-english/, https://github.com/ethereum/wiki/wiki/White-Paper
http://offtheblockchain.com/2014/02/22/read-the-original-satoshi-nakamoto-bitcoin-white-paper/

Economic Arguments for Bitcoin
 Banking services market: 5 billion
individuals worldwide without
access to banking, financial, credit
services
 Remittances market: $4T global
market 5-30% transaction fee,
immediate funds transfer
 Payments market: 1-3% merchant
transaction fee
 Successful examples indicate
demand for digital payments:
Starbucks mobile payment app
October 11, 2014
45

What is Bitcoin Mining?
 The process of adding transaction records to Bitcoin’s public
ledger of past transactions (the blockchain)
 Confirms to the rest of the network that unique transactions
have taken place
 Bitcoin nodes use the block chain to distinguish legitimate
Bitcoin transactions from attempts to re-spend coins that
have already been spent elsewhere
 Intentionally designed to be resource-intensive so that the
number of blocks found each day by miners remains steady
 Individual blocks must contain a proof of work to be
considered valid. This proof of work is verified by other
Bitcoin nodes each time they receive a block. Bitcoin uses
the hashcash proof-of-work function
October 11, 2014
46
http://codinginmysleep.com/bitcoin-mining-in-plain-english/

Bitcoin Protocols 1.0 and 2.0 Explained in the Series: Blockchain: The Information Technology of the Future

More Related Content

What's hot (20)

Viewers also liked (9)

Similar to Bitcoin Protocols 1.0 and 2.0 Explained in the Series: Blockchain: The Information Technology of the Future (20)

More from Melanie Swan (20)

Recently uploaded (20)

Bitcoin Protocols 1.0 and 2.0 Explained in the Series: Blockchain: The Information Technology of the Future