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Do you know…
Just read the following slides to understand all Bitcoin key concepts
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What is the NONCE? What DAO stands for? What is a MERKEL TREE? What UTO stands for? How much is worth 1 SATOSHI?
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DISCLAIMER
Bitcoin is a very complex topic, merging economy, mathemaPcs and IT. This presentaPon aims at
providing a high level overview, and might not be as accurate nor precise as the reality would be. It
somePmes oversimplified explanaPon for the sake of clarity.
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What problem is Bitcoin solving?
InternaPonal Payments and Money Transfer are complex, expensive and
take Pme
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BANKS RELY ON INTERMEDIARIES (CLEARINGHOUSES, CORRESPONDENTS) TO SETTLE PAYMENTS. THERE ARE AT LEAST TWO AREAS OF IMPROVEMENT.
BILATERAL SETTLEMENT WILL ELIMINATES INTERMEDIARIES, MIDPOINT FAILURE, DELAYS, LIFTING FEES
REAL-‐TIME FUNDING WILL MINIMIZES EXCHANGE SPREADS, CREDIT RISK, COLLATERAL COSTS
Source: Ripple Labs (h3ps://ripple.com/solu7ons/execu7ve-‐summary-‐for-‐financial-‐ins7tu7ons/)
Sending bank Receiving correspondent
Receiving bank Sending correspondent / liquidity provider
Central counterparty
Central counterparty
USD USD
USD à EUR
EUR EUR
Libing fees Libing fees
FX cost: $$$
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What is Bitcoin?
Bitcoin is both a protocol and a cryptocurrency, created in 2009 by
Satoshi Nakamoto
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BITCOIN REMOVES THE MIDDLE MAN BY CREATING A TRUSTFUL ENVIRONMENT BETWEEN PEOPLE/ENTITIES WHO DON’T KNOW THEMSELVES, WITHOUT A CENTRAL THIRD-‐PARTY
BITCOIN IS BOTH AN INFRASTRUCTURE (PROTOCOL AND ALGORITHM) AND
A CRYPTOCURRENCY
BITCOIN AS A CRYPTOCURRENCY CAN BE USED TO PAY (LIKE MONEY) OR INVEST (LIKE GOLD)
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BITCOIN TRANSACTIONS ARE IMMUTABLE AND NON-‐REVERSIBLE, THEY CANNOT BE CHANGED
BITCOINT TRANSACTION ARE CENSORLESS, THEY CANNOT BE CENSORED AND REFUSED BY THE NETWORK
BITCOIN CAN BE DIVIDED IN SATOSHI, EQUIVALENT TO 1/100 MILLION BITCOIN. TRANSACTIONS CAN HARDLY BE BELOW 500 SATOSHIS FOR COST EFFICIENCY
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Where does it come from?
Bitcoin combines different field studies, with recent development
enabling powerful soluPons
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NAPSTER WAS ONE OF THE FIRST P2P DISTRIBUTED
NETWORK WITH NO THIRD-‐PARTY INVOLVED
BITCOIN IS AN OPEN SOURCE SOFTWARE MANAGED BY THE BITCOIN FUNDATION
GAME THEORY: MEMBERS PLAYING BY THE RULES IS A NASH EQUILIBRIUM
BITCOIN USES CRYPTOGRAPHY TO SECURE TRANSACTIONS (ELLIPTIC CURVE AND HASH FUNCTION)
DIGICASH WAS ONE OF THE FIRST DIGITAL MONEY FOUNDED IN 1990
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WITH BITCOIN, YOU TRANSFER OWNERSHIP. BITCOINS ARE NON
FUNGIBLE. IT IS LIKE A PHYSICAL ASSET
A TRANSACTION USUALLY PRODUCES 2 OUTPUT: THE ONE SENT TO THE RECEIVER,
AND THE ONE REMAINING TO THE SENDER: UTO (UNSPENT TRANSACTION OUTPUT). TRANSFERING PART OF OWNERSHIP CREATES AN ADDITIONAL TRANSACTION WITH THE LEFT OVER BITCOIN
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TransacPon N-‐1 TransacPon N
1BTC
0.35 BTC
0.65 BTC
WANTS TO TRANSFER 0.35 BTC TO
GENERATE 2 TRANSACTIONS
EACH TRANSACTION IS VALID ONLY IF IT REFERS TO THE PREVIOUS ONE WHICH PROVES OWNERSHIP
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THE CRYPTOCURRENCY IS MINTED EACH TIME A TRANSACTION IS COMPLETED, AND IT CANNOT BE MORE THAN 21 MILLIONS OF BITCOINS. BITCOIN AS A CRYPTOCURRENCY IS A SCARCE RESSOURCE
BITCOINS ARE NOT STORED, THE BALANCE IS THE SUM OF PREVIOUS TRANSACTIONS
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BITCOIN RECORDS TRANSACTIONS AND NOT BALANCE
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TRANSACTIONS ARE SIGNED WITH PUBLIC (address) / PRIVATE KEYS (password), WITH A VERY HIGH LEVEL OF SECURITY WHICH CANNOT BE BROKEN
TO PREVENT FRAUD (DOUBLE SPENDING), TRANSACTIONS ARE RECOREDED IN THE
RIGHT ORDER, WITH A DISTRIBUTED TIMESTAMP
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BITCOIN IS PSEUDONIMOUS (USE OF A PUBLIC KEY TO TRANSACT). BITCOIN DOES NOT GUARANTEE THE ANONYMITY, PSEUDONYMS CAN BE TRANSLATED TO REAL NAME
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How is bitcoin different from fiat currency and physical asset?
Bitcoin is not backed or controlled by any central authority
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USD Gold Bitcoin
Support Paper Metal Digital Scarcity No Yes Yes / Limited to 21 millions CreaYon Minted / Printed Mining Mining Value Defined by government Defined by market Defined by market FuncYons of Money Medium of Exchange Yes ParPal Yes Unit of Account Yes Yes Yes Store of Value Yes Yes Yes
CharacterisYcs of Money Durability Yes Yes Yes Portability Yes Yes Yes Divisibility Yes Limited Yes Uniformity Yes Yes Yes Limited supply Depending on Government Yes Yes / Limited to 21 millions Acceptability Yes ParPal Limited
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WALLETS STORE THE PRIVATE KEY, SIGN THE TRANSACTION AND SEND IT TO THE NETWORK. THE PUBLIC KEY AND IS USED TO SEND / RECEIVE BITCOIN
NODES CHECK THE VALIDITY OF THE TRANSACTION (FORMAT AND RIGHT TO SPEND, ie REFERS TO A PREVIOUS TRANSACTION) AND FORWARD THE TRANSACTION TO THE NEXT NODE
MINERS RECORD THE TRANSACTION, BY VALIDATING THE TIME AND ORDER OF THE TRANSACTIONS (TO PREVENT DOUBLE SPENDING)
miner
miner node
node
node
node
wallet
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TRANSACTIONS ARE RECORDED IN THE BLOCKCHAIN, A DISTRIBUTED DATABASE THAT CONTAINS ALL TRANSACTION FROM GENESIS
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TRANSACTIONS ARE SIGNED WITH CRYPTOGRAPHY AND TURN THE SIGNED TRANSACTION INTO A SECURE 256-‐BIT OUTPUT SIZE USING THE HASH FUCTION (SHA-‐256 PROTOCOL). THIS GUARANTEES THAT THE TRANSACTIONS ARE FULLY SECURED THROUGH ENCRYPTION, LIKE HIDDEN IN A SEALED ENVELOP
TO RECORD TRANSACTIONS, MINERS MUST PROVE THAT THEY HAVE SPENT ENOUGH
EFFORT: THIS IS CALLED PROOF OF WORK, AND MAKES THE BENEFIT OF CHEATING (CREATING FALSE TRANSACTION) LOWER THAN THE EFFORT NEEDED
Private key Public key Encrypted TransacPon
ellipPc curve Hash
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TO PROVE THEIR WORK, MINERS HAVE TO SOLVE COMPLEX MATHS PROBLEMS. SOLUTION IS HARD TO FIND BUT VERY EASY TO CHECK
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IT IS LIKE MAKING A PUZZLE, CALLED A MERKLE TREE, WITHOUT KNOWING THE EXACT PIECES. MINERS HAVE TO TRY DIFFERENT COMBINATIONS OF CURRENT
TRANSACTIONS, WITH A RANDOM FACTOR CALLED THE NONCE
THE SOLUTION IS A BLOCK, AND CONTAINS ALL TRANSACTIONS PART OF THE MERKLE TREE
T5
T9
Nonce
T8
T6
T5
T9
T3
Previous Block
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ONCE THE SOLUTION IS VALIDATED BY THE MAJORITY OF RESSOURCES
(CONSENSUS), THE NEW BLOCK IS ADDED TO THE BLOCKCHAIN, WITH ALWAYS A REFERENCE TO THE PREVIOUS BLOCK
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TO FORGE THE BLOCKCHAIN, A HACKER WOULD HAVE TO FAKE ALL LINKS BETWEEN THE DIFFERENT TRANSACTIONS (BLOCKS), WHICH IS TOO MUCH WORK COMPARED TO BENEFITS
MINERS ARE INCENTIVIZED TO RECORD THE TRANSACTIONS BY RECEIVING NEW BITCOINS AND TRANSACTION FEES
THE FIRST TRANSACTION OF A BLOCK IS THE COINBASE AND IS ABOUT THE BITCOINS THE MINER IS GOINT TO GET FOR MINING
Block N-‐2 Block N-‐1 Block N
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Is Bitcoin limited to money transfer?
Bitcoin has been designed first for payment but coins can carry
addiPonal informaPon
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COINS ARE ACTUALLY LIKE TOKENS, CARRYING ATTRIBUTES. AS BITCOINS ARE NOT
FUNGIBLE, THEY CAN BE COLORED TO BE TRACKED AND TO REPRESENT OTHER ASSETS (EQUITY FOR INSTANCE)
WALLETS CAN BE SMART, WITH COMPUTATION OF CONDITIONS AND AUTOMATIC EXECUTION OF CONTRACTS, WITH INSIDE OR OUTSIDE EVENTS, TO BECOME
SMART CONTRACTS When 1 bitcoin is received, then send the digital key to open the door (eg for P2P lodging services like AirBnB)
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BASED ON THE BITCOIN INFRASTRUCTURE, SERVICES CAN NOW BE PROVIDED WITHOUT A CENTRALIZED PARTY AS DECENTRALIZED AUTONOMOUS ORGANIZATION
(DAO)
WHEN NEED, ORACLE ARE USED TO PROVIDE EXTERNAL DATA TO AUTOMATE CONTRACT EXECUTION, AS FOR INSTANCE INSURANCE ON TRAVEL DELAYS (USING DATA ON DELAYS)
AS BITCOIN WAS FIRST DESIGNED TO MANAGE CRYPTOCURRENCY, AND TO NOT INTERFERE OR TO GET MORE FLEXIBILITY, SOME OTHER BLOCKCHAINS ARE MOVING
TO A SEPARATE FORK (DEDICATED INSTANCE OF BITCOIN) TO MANAGE SPECIFIC
ASSETS manages DNS entry on the web
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THERE ARE 2 KIND OF WALLETS TO STORE BITCOINS: HOT WALLETS AND COLD WALLETS.
COLD WALLETS ARE MORE SECURE AND PHYSICALLY STORE THE COINS ON A HARDWARE (USB KEYS, PC, ETC.) OR A PAPER (PRIVATE KEY) WITHOUT BEING CONNECTED TO INTERNET
HOT WALLETS ARE WEB-‐HOSTED (CLOUD) AND ARE EASILY MANAGED. THEY STORE THE PRIVATE KEY AND ARE PROTECTED BY A MORE TRADITIONAL PASSWORD
TO GET BITCOINS, YOU CAN EASIER GET THEM FROM AN EXISTING USER, OR CONVERT
FIAT CURRENCY INTO BITCOINS USING A BITCOIN GATEWAY
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Can Bitcoin the protocol live without bitcoin the currency?
Bitcoin opens the road to distributed consensus and lots of applicaPons
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BITCOIN THE CURRENCY IS THE INCENTIVE TO PARTICIPATE TO THE P2P NETWORK BITCOIN AND IS PART OF THE BUSINESS MODEL OF MINERS
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THE ONLY WAY TO WORK WITHOUT A CURRENCY IS TO WORK IN CLOSE LOOP,
REMOVING THE PROOF OF WORK REQUIREMENT, WITH PERMISSIONED
BLOCKCHAIN (VS PERMISSIONLESS AS IS BITCOIN), ACCESSIBLE ONLY TO AUTHORIZED MEMBERS, SUCH AS BANKS
R3CEV IS AN EXAMPLE OF PERMISSIONED BLOCKCHAIN, TRYING TO SET UP
A NEW STANDARD FOR DISTRIBUTED LEDGER, IN DIRECT COMPETITION WITH SWIFT
THE COST OF MINING IS INCREASING, REQUIRING MORE AND MORE CPU (ENERGY). IT BECOMES VERY HARD TO MAKE MONEY WITH MINING. MINERS REGROUP
THEMSELVES INTO MINING POOL, IN ORDER TO MUTUALIZE COSTS
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AS MINING GETS MORE AND MORE EXPENSIVE, THE OTHER BLOCKCHAINS CANNOT ALL AFFORD TO MOTIVATE MINERS, AND THEREFORE TEND TO USE BITCOIN MINING AND INCENTIVE AS WELL
THE 2 WAY PEG PROTOCOL ENABLE DOUBLE MINING FOR 2 DIFFERENT BLOCKCHAINS AND SHOULD REINFORCE THE LEADERSHIP OF BITCOIN AS THE LEADING CRYPTOCURRENCY
THE DIFFERENT BLOCKCHAINS GET LINKED, BITCOIN BEING THE CORNER STONE WITH
SOME EXTENSIONS TOWARDS THE OTHERS AS SIDECHAINS
BITCOIN SIDECHAINS
Security management
Property Registry management
Birth cerPficates
Smart Contracts
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What is the future of Bitcoin?
Bitcoin opens the road to distributed consensus and lots of applicaPons
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MINING POOLS CAN BECOME OVERWEIGHED, AND CAN REPRESENT MORE THAN 50% OF THE AVAILABLE RESOURCES, BECOMING ABLE TO TWIST CONSENSUS. CURRENTLY, CHINESE MINERS REPRESENT MORE THAN 50% OF MINING RESOURCES
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PROOF OF WORK MIGHT NOT BE THE BEST PROTOCOL,
PROOF OF STAKE FOR INSTANCE IS BASED ON THE ACTUAL OWNERSHIP OF VALUE. NEW
BLOCKCHAINS ARE EMERGING, LIKE ETHEREUM, WITH ITS OWN CURRENCY ETHER
STANDARDIZATION IS COMPLEX, CHANGES IN THE BITCOIN SOFTWARE REQUIRES A CONSENSUS WITHIN CORE DEVELOPERS WHICH IS SOMETIMES DIFFICULT TO ACHIEVE
BITCOIN AS A CURRENCY MIGHT NOT SURVIVE, BUT BITCOIN AS A PROTOCOL HAS
BEEN LEADING THE PATH TO THE INTERNET OF VALUE, A NEW ORGANIZATION WITHOUT THIRD-‐PARTY