Laravel, the Blockchain, and You!

You've heard the buzz, but is blockchain a technology worth exploring? In this talk, I compare/contrast storing data on the blockchain with traditional MySQL databases, talk about some real-world companies using blockchain technology in production, and share some resources for adding blockchain to your web apps.

Transcript

1. Laravel,
   the Blockchain,
   and YOU
   

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3. Things you know about blockchain technology (if you're
   anything like me 6 months ago)
   ▸ It's a buzzword that people are arguing about on Twitter/Reddit
   ▸ It has coins? Or something...?
   ▸ One of those coins is Bitcoin and I really wish I'd invested in it like 6
   years ago when I first heard about it
   ▸ I have no idea if I can use it with Laravel apps
   

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4. (Spoiler alert: you can use
   it with Laravel apps)
   

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5. But should you?
   

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6. Some people:
   

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7. But then there's
   this:
   

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8. So should I use a blockchain?
   Probably not
   (unless you're trying to solve a very specific problem.)
   

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9. Stuff I'm going to talk at you about:
   1) What is a blockchain/cryptocurrency?
   2) How is it better/worse than a MySQL database?
   3) When should you consider a blockchain for your app?
   4) How do you get started with Laravel/Vue?
   

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10. But before we begin...
    Visit https://chat.laracon.net/c/speaker-questions
    Find the thread called "[Samantha Geitz] Blockchain Game"
    Have it open in the background — you'll need it in 15 minutes or so!
    I will name the winner the "Elitest of the Laravel Elites" on Twitter
    

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11. Let's talk about MySQL
    ▸ Single database, sitting behind a server, acting as the source of
    truth for all clients connecting to an app
    ▸ To write data, you either add a new value or update an existing one
    ▸ Anyone who has access to database can change data
    ▸ If database is deleted or server goes down, data is inaccessible
    ▸ Works kinda like an Excel spreadsheet
    

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13. How is blockchain different?
    ▸ Blockchains are decentralized — a network is made up of various
    "nodes" (computers) with a copy of the entire database
    ▸ Apps can read data and add new records but not edit data
    ▸ To update data, new "blocks" of data are added to the chain to show
    how existing data should change
    

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14. ▸ Works more like a ledger with records written one after another in
    permanent ink, or a git repository with sequential commits
    ▸ If you try to edit/change/erase data in your blockchain, it will be
    different than everyone else's copy of the data history
    ▸ All nodes on network work together to ensure a consensus on data,
    which is highly secure
    

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16. OK, what's the catch?
    ▸ Every time anything happens, every computer on the network needs
    to come to an agreement that it took place. Meaning:
    ▸ It's slooooooooooow
    ▸ It's comparatively very expensive
    ▸ "Roughly, a good heuristic to use is that you will not be able to do
    anything that you cannot do on a smartphone from 1999.”
    

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17. So why would you use it?
    3 real-world examples
    (And one fake Laravel app)
    

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18. Bitcoin
    

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19. Problems being solved:
    ▸ With traditional currency, banks and/or governments have control
    over people's money
    ▸ Nothing to stop governments releasing an unlimited supply of money
    ▸ Credit card fraud / forged currency
    ▸ Risk of transactions being disputed/reversed
    

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20. How does it work?
    ▸ You want to send me a Bitcoin because you loved my talk
    ▸ Two ways to get Bitcoin: buying them on an exchange or "mining"
    them (which we will talk about later)
    ▸ Add your computer as a "node" to the network by downloading the
    Bitcoin software, including a copy of the entire history (150GB)
    ▸ This software is known as a "wallet"
    

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21. Is that a wallet in your pocket or are you just
    happy to see me
    ▸ Wallets do not technically store coins. They contain:
    ▸ Private key: large, secret, randomly-generated string unique to you.
    How you identify yourself — never share this with anyone!
    ▸ Public key: code created via algorithm from private key — how
    others can find you on the network
    

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22. How does it work?
    ▸ You enter my public key in your wallet and indicate you want to send
    me 1 bitcoin (thanks!!!)
    ▸ Your wallet tells the network that you want to send me a coin and
    "signs" the transaction info with your private key, creating a hash
    ▸ Transactions can be validated with your public key and the hash
    without ever revealing your private key
    

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23. Hashing in Laravel
    ▸ Your user signs up and enters "foobar" as a password
    ▸ You save it with Hash::make($password)
    ▸ It is stored in your DB as
    $2y$10$hEEF0lv4spxnvw5O4XyLZ.QjCE1tCu8HjM
    pWhmCS89J0EcSW0XELu
    ▸ Can check 'foobar' against hash; cannot decrypt hash into 'foobar'
    

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24. Adding data to blockchain
    ▸ Need a way to incentivize people to maintain the integrity of the
    network (which takes a lot of computing power)
    ▸ Solution: mining!
    ▸ Mining nodes validate "blocks" (groups of transactions) and add
    them to the blockchain
    ▸ Reward: bitcoins (currently, about $47,500 worth)
    

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25. Ready for that game I mentioned earlier?
    This is your 2-minute warning!
    

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26. A quick guide to mining
    ▸ There is a small cost to putting a transaction on the network
    ▸ This is basically your bidding to put their transaction in the miner's
    solved block
    ▸ The network sends these groups of transactions as a hash created
    with a nonce (short for number used once)
    

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27. Game time!
    

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28. You are all miners
    I am thinking of a number between 1 and 200
    The first person to guess it in the chat wins
    You have unlimited guesses. Go! Go! Go!
    

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29. A quick guide to mining
    ▸ Mining nodes guess random numbers as quickly as possible to figure
    out the correct 256-bit number
    ▸ The first miner to guess it is rewarded 12.5 bitcoins, plus the
    transaction fees. Everyone else loses.
    ▸ Verified transactions are added onto the blockchain as a new block
    ▸ More powerful hardware = better odds of guessing nonce
    

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30. What if you try to spend a coin twice?
    ▸ Network has a globally-accepted order of transactions
    ▸ If two transactions contradict each other, the one that ends up being
    second will be rejected and cannot become part of a block
    

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31. OK, but why "mining?"
    ▸ Bitcoin protocol = max of 21 million bitcoins will ever exit
    ▸ (This is expected to happen around 2140)
    ▸ New bitcoins are "dug up" as the network is maintained
    ▸ Currently, 12.5 BTC reward for successful mining
    ▸ This amount halves every 4 years or so (eventually will basically be
    only transaction fees)
    

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32. Bitcoin lets you send
    "money," but what about
    other data?
    

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33. Bitcoin vs. Ethereum
    ▸ Ethereum is another blockchain technology that allows you to easily
    build decentralized apps (Dapps)
    ▸ Has "smart contracts" that can store data / business logic and talk
    to each other
    ▸ Built in JavaScript
    

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34. Ethereum mining
    ▸ Similar to Bitcoin mining, except you mine "ether"
    ▸ Ether is "gas," or computational power used to add data to the
    blockchain
    ▸ When you send a transaction, you set max gas you are willing to pay
    ▸ Gas left over is refunded
    ▸ Possible to get partial credit for mining, unlike Bitcoin
    

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35. Microsoft
    Xbox
    

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36. Problems being solved:
    ▸ It is very difficult to figure out Xbox game publisher royalties
    ▸ Microsoft accountants have to deal with printed documentation and
    manual Excel spreadsheets to reconcile/recalculate royalty
    payments
    ▸ Different publishers / locales have different requirements
    ▸ It generally takes about 45 days for publishers to get their money
    

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37. Solution
    ▸ Smart contracts on a distributed blockchain
    ▸ Stakeholders can see how contract is set up and calculated
    ▸ Publishers get paid (and actionable data) almost immediately
    ▸ New system reduces transaction costs for publishers by 99% and
    cuts Microsoft's operating costs in half
    

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38. Webjet
    

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39. Problems being solved:
    ▸ I have a hotel room I want to rent out
    ▸ A travel agency, Expedia, Hotels.com, the hotel chain, and the
    receptionist at the front desk are all using different systems to book
    ▸ An estimated 5% of bookings are disputed
    ▸ This is a nightmare on both the accounts receivable and accounts
    payable ends
    

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40. Solution
    ▸ Webjet created Rezchain, an Ethereum blockchain to share booking
    data between all partners
    ▸ Not reliant on any one partner's infrastructure
    ▸ Disputes are fewer, and happen very near the time of the original
    transaction, not at the hotel or when losses are discovered
    

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41. Possible good uses for blockchain tech
    ▸ Voting app
    ▸ DRM management of media/games
    ▸ Any app where the verifying the identity of participants is
    important: financial, legal, doctor writing a prescription, etc.
    

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42. Bad use cases for blockchain tech
    ▸ Most things
    ▸ Data is in constant flux
    ▸ You want/need the ability to manually control the current state of
    data (remove/correct records)
    ▸ Speed/performance (need data in ms) is a priority
    

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43. Laravel Elites
    (A hypothetical v2)
    

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44. laravelelites.com
    ▸ The new de facto standard for hiring Laravel devs!
    ▸ Now with Github OAuth2 login via Socialite
    ▸ A few prominent people in the community can make people "Laravel
    Elite" via a certification process
    ▸ They have a secret API key and can add data to the database
    

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46. !
    

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49. !
    

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50. But what if it was on the blockchain?
    ▸ If multiple people were running copies of the blockchain, they could
    see that I edited his info
    ▸ I'd have to stick to a good old-fashioned Twitter fight
    

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51. Developing blockchain
    applications: stuff to know
    

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52. web3.js
    ▸ Main JavaScript library for interacting with Ethereum
    ▸ There are a few web3 PHP implementations as well; if you try them,
    let me know if they're good!
    

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53. Truffle Suite
    https://truffleframework.com
    

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54. Truffle Framework
    ▸ Open-source Ethereum development framework
    ▸ Manage and test your smart contracts
    ▸ Various "boxes" for quickstart with Vue, React, etc.
    

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55. Ganache
    ▸ Sets up a personal blockchain for local development
    ▸ Desktop app (via Electron/JS) or CLI tool
    ▸ Has built-in block explorer to see blocks/transactions
    

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56. Ganache
    

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57. Drizzle
    ▸ Collection of libraries built on top of Redux to synchronize contract
    and transaction data
    ▸ Not a lot of Vue tooling around Drizzle yet (although there are
    several Vue Truffle boxes)
    ▸ #teamreact
    

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58. MetaMask
    ▸ Web extension you can install via Chrome
    ▸ Manage your Ethereum private keys via web browser
    ▸ Serves as a web wallet that lets you visit blockchain apps without
    running a full Ethereum node
    

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59. MetaMask
    

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60. Solidity
    ▸ Object-oriented, statically-typed language for implementing smart
    contracts
    ▸ Truffle lets you "migrate" smart contracts, compiling them to JSON
    and storing them on the blockchain
    

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61. Solidity
    pragma solidity >=0.4.0 <0.6.0;
    contract SimpleStorage {
    uint storedData;
    function set(uint x) public {
    storedData = x;
    }
    function get() public view returns (uint) {
    return storedData;
    }
    }
    

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62. CoinPress
    ▸ (My shameless self-promotion slide)
    ▸ Side project I created with @PolewskiEric
    ▸ Create your own production Ethereum blockchain in seconds
    ▸ Free node hosting
    ▸ In active development; more coming soon!
    

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63. CoinPress
    https://coinpress.cc
    

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64. Before we look at code...
    If you enjoyed my talk, follow:
    @SamanthaGeitz
    @PolewskiEric
    @CoinpressCC
    

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65. Coming up next: @stauffermatt
    

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66. Let's look at some code!
    

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