Hands On Step by Step Building Bitcoin like Blockchain in Substrate/RUST with the help of "Build a Bitcoin-like Blockchain with Substrate Youtube Playlist"

[Original Inspiration] (https://www.youtube.com/watch?v=qaykNPHJcyw&list=PLp0_ueXY_enXeTURZk2frt7muxf2Hz6sN)

2. Used basic utxo template

Clone your copy of the workshop codebase

git clone https://github.com/substrate-developer-hub/utxo-workshop.git

Original Readme credits below

UTXO on Substrate

A UTXO chain implementation on Substrate, with two self-guided workshops.Original UXTO inspiration by Dmitriy Kashitsyn.

Substrate Version: 2.0.0-alpha.5. For educational purposes only.

Table of Contents

• Installation: Setting up Rust & Substrate dependencies

• UI Demo: Demoing this UTXO implementation in a simple UI

• Beginner Workshop: A self guided, 1 hour workshop that familiarizes you with Substrate basics

• Advanced Workshop: A self guided, 2 hour video tutorial, that teaches you how to build this UTXO blockchain from scratch

• Helpful Resources: Documentation and references if you get stuck in the workshops

Installation

1. Install or update Rust

curl https://sh.rustup.rs -sSf | sh

# On Windows, download and run rustup-init.exe
# from https://rustup.rs instead

rustup update nightly
rustup target add wasm32-unknown-unknown --toolchain nightly
rustup update stable
cargo install --git https://github.com/alexcrichton/wasm-gc

2. Clone this workshop

Clone your copy of the workshop codebase

git clone https://github.com/substrate-developer-hub/utxo-workshop.git

UI Demo

In this UI demo, you will interact with the UTXO blockchain via the Polkadot UI.

The following demo takes you through a scenario where:

• Alice already owns a UTXO of value 100 upon genesis
• Alice sends Bob a UTXO with value 50, tipping the remainder to validators

1. Compile and build a release in dev mode

# Initialize your Wasm Build environment:
./scripts/init.sh

# Build Wasm and native code:
cargo build --release

2. Start your node & start producing blocks:

./target/release/utxo-workshop --dev

# If you already modified state, run this to purge the chain
./target/release/utxo-workshop purge-chain --dev

3. In the console, notice the helper printouts. In particular, notice the default account Alice was already has 100 UTXO upon the genesis block.

4. Open Polkadot JS, making sure the client is connected to your local node by going to Settings > General, and selecting Local Node in the remote node dropdown.

5. Declare the custom datatypes in PolkadotJS, since the JS client cannot authomatically infer this from the UTXO module. Go to Settings > Developer tab and paste in the following JSON:

{
  "Address": "AccountId",
  "LookupSource": "AccountId",
  "Value": "u128",
  "TransactionInput": {
    "outpoint": "Hash",
    "sigscript": "H512"
  },
  "TransactionOutput": {
    "value": "Value",
    "pubkey": "Hash"
  },
  "Transaction": {
    "inputs": "Vec<TransactionInput>",
    "outputs": "Vec<TransactionOutput>"
  }
}

6. Confirm that Alice already has 100 UTXO at genesis. In Chain State > Storage, select utxo. Input the hash 0x76584168d10a20084082ed80ec71e2a783abbb8dd6eb9d4893b089228498e9ff. Click the + notation to query blockchain state.

   Notice that:

   • This UTXO has a value of 100
   • This UTXO belongs to Alice's pubkey. You use the subkey tool to confirm that the pubkey indeed belongs to Alice

7. Spend Alice's UTXO, giving 50 to Bob. In the Extrinsics tab, invoke the spend function from the utxo pallet, using Alice as the transaction sender. Use the following input parameters:

   • outpoint: 0x76584168d10a20084082ed80ec71e2a783abbb8dd6eb9d4893b089228498e9ff
   • sigscript: 0x6ceab99702c60b111c12c2867679c5555c00dcd4d6ab40efa01e3a65083bfb6c6f5c1ed3356d7141ec61894153b8ba7fb413bf1e990ed99ff6dee5da1b24fd83
   • value: 50
   • pubkey: 0x8eaf04151687736326c9fea17e25fc5287613693c912909cb226aa4794f26a48

   Send this as an unsigned transaction. With UTXO blockchains, the proof is already in the sigscript input.

8. Verify that your transaction succeeded. In Chain State, look up the newly created UTXO hash: 0xdbc75ab8ee9b83dcbcea4695f9c42754d94e92c3c397d63b1bc627c2a2ef94e6 to verify that a new UTXO of 50, belonging to Bob, now exists! Also you can verify that Alice's original UTXO has been spent and no longer exists in UtxoStore.

Coming soon: A video walkthrough of the above demo.

Beginner Workshop

Estimated time: 2 hours

In this workshop, you will:

• Get familiar with basic Rust and Substrate functionality
• Prevent malicious users from sending bad UTXO transactions

Your challenge is to fix the code such that:

1. The Rust compiler compiles without errors
2. All tests in utxo.rs pass, ensuring secure transactions

Directions

1. Checkout the workshop branch. The Master branch has the solutions, so don't peek!

git fetch origin workshop:workshop
git checkout workshop

2. Cd into the base directory. Try running the test with: cargo test -p utxo-runtime.

compiling utxo-runtime v2.0.0 (/Users/nicole/Desktop/utxo-workshop/runtime)
error[E0433]: failed to resolve: use of undeclared type or module `H512`
   --> /Users/nicole/Desktop/utxo-workshop/runtime/src/utxo.rs:236:31
    |
236 |             input.sigscript = H512::zero();
    |                               ^^^^ use of undeclared type or module `H512`

...

3. Your first task: fix all the compiler errors! Hint: Look for the TODO comments in utxo.rs to see where to fix errors.

4. Once your code compiles, it's now time to fix the 8 failing tests!

failures:
    utxo::tests::attack_by_double_counting_input
    utxo::tests::attack_by_double_generating_output
    utxo::tests::attack_by_over_spending
    utxo::tests::attack_by_overflowing_value
    utxo::tests::attack_by_permanently_sinking_outputs
    utxo::tests::attack_with_empty_transactions
    utxo::tests::attack_with_invalid_signature
    utxo::tests::test_simple_transaction

5. In utxo.rs, edit the logic in validate_transaction() function to make all tests pass.

running 8 tests
test utxo::tests::attack_by_overflowing_value ... ok
test utxo::tests::attack_by_double_counting_input ... ok
test utxo::tests::attack_by_double_generating_output ... ok
test utxo::tests::attack_by_over_spending ... ok
test utxo::tests::attack_with_empty_transactions ... ok
test utxo::tests::attack_with_invalid_signature ... ok
test utxo::tests::attack_by_permanently_sinking_outputs ... ok
test utxo::tests::test_simple_transaction ... ok

Advanced Workshop

VIDEO TUTORIALS COMING SOON

Estimated time: 1 hour

In this workshop, you will implement this UTXO project from scratch using Substrate.

You will learn:

• How to implement the UTXO model on Substrate
• How to secure UTXO transactions against attacks
• How to seed genesis block with UTXOs
• How to reward block validators in this environment
• How to customize transaction pool logic on Substrate
• Good coding patterns for working with Substrate & Rust

Helpful Resources

• Substrate documentation
• bytes to Vec converter
• Polkadot UI