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Laravel, the Blockchain, and You!

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.


Samantha Geitz

March 06, 2019


  1. Laravel, the Blockchain, and YOU

  2. None
  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
  4. (Spoiler alert: you can use it with Laravel apps)

  5. But should you?

  6. Some people:

  7. But then there's this:

  8. So should I use a blockchain? Probably not (unless you're

    trying to solve a very specific problem.)
  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?
  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
  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
  12. None
  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
  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.”
  17. So why would you use it? 3 real-world examples (And

    one fake Laravel app)
  18. Bitcoin

  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
  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"
  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
  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
  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'
  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)
  25. Ready for that game I mentioned earlier? This is your

    2-minute warning!
  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)
  27. Game time!

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

  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
  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
  35. Microsoft Xbox

  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
  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
  38. Webjet

  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
  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
  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.
  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
  43. Laravel Elites (A hypothetical v2)

  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
  45. None
  46. !

  47. None
  48. None
  49. !

  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
  51. Developing blockchain applications: stuff to know

  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!
  53. Truffle Suite https://truffleframework.com

  54. Truffle Framework ▸ Open-source Ethereum development framework ▸ Manage and

    test your smart contracts ▸ Various "boxes" for quickstart with Vue, React, etc.
  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
  56. Ganache

  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
  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
  59. MetaMask

  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
  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; } }
  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!
  63. CoinPress https://coinpress.cc

  64. Before we look at code... If you enjoyed my talk,

    follow: @SamanthaGeitz @PolewskiEric @CoinpressCC
  65. Coming up next: @stauffermatt

  66. Let's look at some code!