nikalexis nikos - nikalexis@gmailnikalexis nikos - [email protected] concept digital money...

Nikalexis Nikos - [email protected]


Blockchain


A --> B 35


A --> B 35A --> B 35


A --> B 35A --> B 35

A --> B 35

A --> B 35

A --> B 35

A --> B 35

A --> B 35


A --> B 35D --> E 42C --> F 78

NEXT BLOCK

Searching for a small hash...

NEXT BLOCK


A --> B 35D --> E 42


A --> B 35D --> E 42C --> F 78

NEXT BLOCK

Solution found!

NEXT BLOCK

A --> B 35D --> E 42



A --> B 35D --> E 42C --> F 78

NEXT BLOCK

A --> B 35D --> E 42C --> F 78

A --> B 35D --> E 42C --> F 78

A --> B 35D --> E 42C --> F 78

A --> B 35D --> E 42C --> F 78

A --> B 35D --> E 42C --> F 78

Abort searching

Solution found!


~10 minutes


Value proposition


= +● Optimizations

○ Fast transactions○ Upgradability

● Decentralized apps○ Programming language○ Smart contracts (API)

● Compute engine○ Storage / database○ Pay-as-you-go

● Ethereum foundation○ Users / devs community○ Constant development


Concept Digital money Decentralized applications

Transaction Send from Alice to Bob Send from Alice to Bob - On 1/6/2017 - If Bod’s balance < 10

Average block time ~10 minutes ~14 seconds

Founder Unknown Vitalik Buterin and team

Release method Early mining Crowdfunding $ 18M + 12M in ether

Development Uncertain / miners driven Ethereum foundation

Release date January 2009 July 2015

Market capitalization (25/5/2017)

$ ~43 billion $ ~18 billion


Smart contractsTrading example


SELLERBUYER


SELLERBUYER

Problems:Buyer could be a scammerSeller could be a scammer


SELLERBUYER ESCROW


SELLERBUYER ESCROW

Problems:Escrow could be a scammerEscrow applies some fees


SELLERBUYER


BUYER SELLERSMART CONTRACT


SELLERBUYER SMART CONTRACT

OK


SELLERBUYER SMART CONTRACT

OK X



executes:

i_am_the_buyer( )executes:

i_am_the_seller( )



received()



X



X

cancel()


Smart contractsDNS example


Acme Inc. DNSSMART

CONTRACT


Acme Inc. DNSSMART

CONTRACT

executes:register(“acme.com”, “2 Years”, )


Acme Inc. DNSSMART

CONTRACT


executes:set_ns(“acme.com”, “1.2.3.4”)


Acme Inc. DNSSMART

CONTRACT


executes:set_ns(“acme.com”, “1.2.3.4”)

executes:extend(“acme.com”, “1 Year”, )


Smart contractsBidding example


Bidder #1

DNSSMART

CONTRACT

executes:register_bid(“acme.com”, )


Bidder #1

DNSSMART

CONTRACT


Bidder #2executes:register_bid(“acme.com”, )


Bidder #1

DNSSMART

CONTRACT





executes after bidding end period:bid_ended( )

Bidder #1

DNSSMART

CONTRACT

Bidder #2

Winner!





Bidder #1

DNSSMART

CONTRACT

Bidder #2

Winner!



now can execute:set_ns(“acme.com”, “1.2.3.4”)


Solidity language


pragma solidity ̂ 0.4.0;

contract SimpleStorage { uint storedData;

function set(uint x) { storedData = x; }

function get() constant returns (uint) { return storedData; }}


pragma solidity ̂ 0.4.0;

contract Coin { // The keyword "public" makes those variables // readable from outside. address public minter; mapping (address => uint) public balances;

// Events allow light clients to react on // changes efficiently. event Sent(address from, address to, uint amount);

// This is the constructor whose code is // run only when the contract is created. function Coin() { minter = msg.sender; }

function mint(address receiver, uint amount) { if (msg.sender != minter) return; balances[receiver] += amount; }

function send(address receiver, uint amount) { if (balances[msg.sender] < amount) return; balances[msg.sender] -= amount; balances[receiver] += amount; Sent(msg.sender, receiver, amount); }}


Tokens


ether


ether

Fiat currencies


Commodities

ether

Fiat currencies


Commodities

ether

Fiat currenciesStocks


Commodities

ether

Domain namesFiat currencies

Stocks


Commodities

ether

Domain names

IPv4/v6 ranges

Fiat currenciesStocks


Commodities

ether

Domain names

IPv4/v6 ranges

Fiat currencies Voting tokens / DAOsStocks


Commodities

ether

Domain names

IPv4/v6 ranges

Fiat currencies Voting tokens / DAOsStocks

Crowfunding /ICOs


Community


Ethereum Foundation


Users / Developers


EEA MEMBERS


Thank you!Questions?

nikalexis nikos - nikalexis@gmailnikalexis nikos - [email protected] concept digital money...

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