BloqueChain

BloqueChain is a custom blockchain network built using Node.js. It leverages a peer-to-peer (P2P) architecture to maintain a decentralized network of nodes. This project uses LevelDB, a name-value database, for persistently storing blocks. It also features a comprehensive API for block and wallet information retrieval, alongside a command-line interface for interaction with the API.

Getting Started

To set up and run BloqueChain, follow these steps:

1. Install dependencies using: npm install.
2. Create database, mine genesis block, initialize HTTP server and Start a node using: node p2p.js.

Features

• P2P Network: Establishes a basic peer-to-peer network for node communication.
• Block Handling: Supports sending and receiving blocks between nodes.
• Miner Registration: Allows for the registration of miners and creation of new blocks.
• LevelDB Integration: Utilizes LevelDB for storing blocks in a name-value pair database.
• Wallet Creation: Implements a system for creating private-public key wallets.
• API: Offers an API for data retrieval and interaction with the blockchain.
• CLI: Provides a command-line interface for easy interaction with the blockchain network.
• Transaction Creation: Supports creating transactions via the API and command line.
• Transaction Handling: Transactions are verified by miners and added to the next block.

Block Structure

Example:

{
    "blockHeader": {
        // Indicates the block version.
        "version":1,
        // SHA-256 hash of the previous block’s header.
        "previousBlockHeader":"<hash>",
        // Hash of all key-value pairs in the block's Merkle tree.
        "merkleRoot":"<hash>",
        // Unix epoch time of block creation.
        "time":<Unix timestamp>
    },
    // Identifies the block's position in the chain, with the GenesisBlock at index 0.
    "index":<number>,
    // Contains the transaction data within the block.
    "txns":[{
        // Unique identifier of the transaction.
        "hash": "<hash>",
        // A counter used to ensure each transaction can only be processed once.
        "nonce": <number>,
        // The hash of the block in which this transaction is recorded.
        "blockHash": "<hash>",
        // The number of the block in which this transaction is recorded.
        "blockNumber": <number>,
        // The index position of the transaction in the block.
        "transactionIndex": <number>,
        // The address of the sender.
        "from": "<hash>",
        // The address of the receiver.
        "to": "<hash>",
        // The amount being transferred
        "value": <number>,
        // The maximum amount of gas the sender is willing to use in the transaction.
        "gas": <number>,
        // The price the sender is willing to pay per unit of gas, in wei.
        "gasPrice": <number>,
        // Data sent along with the transaction, used for contract interaction.
        "input": "<hash>",
        // The digital signature of the sender
        "signature": {
            "r": "<hash>",
            "s": "<hash>",
            "recoveryParam": <number>
        }
    }]
}

Consensus

BloqueChain adopts a Proof-of-Stake (PoS) approach. Each peer registers as a miner and takes turns mining blocks. Blocks are generated every 30 seconds using the Node.js cron library.

Message Types

REQUEST_BLOCK: Requests block information for a certain block index
RECEIVE_NEXT_BLOCK: Requests information for the next block
RECEIVE_NEW_BLOCK: Notifies node of new block
REQUEST_ALL_REGISTER_MINERS: Request for all registered miners
REGISTER_MINER: Request to register miner

API Documentation

Retrieve All Blocks

Endpoint: /blocks
Method: GET
Description: Retrieves all blocks in the blockchain.
Response: JSON array of blocks.

Retrieve a Single Block

Endpoint: /getBlock
Method: GET
Query Parameters: - index (integer) - Index of the block to retrieve.
Description: Retrieves a block based on its index.
Response: JSON object of the block.

Retrieve a Block from LevelDB

Endpoint: /getDBBlock
Method: GET
Query Parameters: - index (integer) - Index of the block in the LevelDB database.
Description: Retrieves a block from the LevelDB database based on its index.
Response: JSON object of the block from the database.

Retreive Mempool

Endpoint: /mempool
Method: GET
Description: Retrieves all pending transactions in the mempool.
Response: JSON array of transactions.

Retrieve a Transaction from LevelDB

Endpoint: /getDBTransaction
Method: GET
Query Parameters: - hash - Hash of the transaction in the LevelDB database.
Description: Retrieves a transaction from the LevelDB database based on its hash.
Response: JSON object of the transaction from the database.

Generate Wallet

Endpoint: /getWallet
Method: GET
Description: Generates a public-private key pair for a new wallet.
Response: JSON object with wallet details (public and private keys).

Command Line Interface Documentation

See here.

License

This project is licensed under the MIT License.