Vulkan Core

Overview

Vulkan is a high-performance cryptocurrency implementation written in C that focuses on efficiency and modularity. The codebase features a complete RPC server interface, peer-to-peer networking, and blockchain management systems.

Core Components

RPC Server

• Full Bitcoin-compatible JSON-RPC API implementation
• Supports all standard mining and blockchain query operations
• Thread-safe request handling with connection pooling
• CORS support for web integrations
• Comprehensive error handling and logging

Key RPC methods:

Compression and Storage Options

Vulkan supports both RocksDB and LevelDB for efficient data storage. Developers can choose RocksDB for high write throughput or LevelDB for simplicity and smaller memory footprints, depending on the use case. It provides customizable compression options, including:

• Snappy Compression
• LZ4 Compression
• Zstandard Compression

Developers can toggle compression using set_want_blockchain_compression() and set specific compression algorithms with set_blockchain_compression_type().

Genesis Block Initialization

During blockchain initialization, Vulkan validates and inserts the genesis block. This ensures a solid foundation for the blockchain, whether operating in mainnet or testnet mode.

Block and Transaction Validation

Vulkan employs rigorous validation checks, including:

• Timestamp Validation: Ensures blocks are not timestamped too far in the future.
• Merkle Root Verification: Confirms transaction integrity within a block.
• Proof-of-Work Checks: Verifies that blocks meet the required difficulty.

Blockchain Database Management

Vulkan offers comprehensive tools for managing blockchain data:

• Database Repair: Functions like repair_blockchain() fix corrupted databases.
• Backup and Restore: Backup functionality is implemented with backup_blockchain() and restore_blockchain().
• Rollback Mechanism: The blockchain can rollback to a specific height using rollback_blockchain().

Mining and Difficulty Adjustment

Vulkan dynamically adjusts mining difficulty based on block production times, ensuring stable block intervals even during fluctuations in network activity. For example, in periods of increased miner participation, difficulty rises to maintain balance. This ensures consistent block generation, using functions like get_next_work_required() to calculate difficulty.

Merkle Tree Implementation

Transactions are organized into Merkle trees, with the root hash stored in each block. This provides a fast and efficient way to verify transaction integrity.

Peer-to-Peer Communication Protocol

Vulkan’s P2P communication protocol manages the interactions between nodes on the network, ensuring a secure and efficient decentralized system. For instance, during blockchain synchronization, nodes utilize grouped synchronization to transfer multiple blocks simultaneously, reducing latency.

Packet Structure

• Packets: Serialized structures containing:
  • id: Packet type identifier.
  • size: Payload size.
  • data: Payload data.
• Serialization and deserialization are handled by serialize_packet() and deserialize_packet() functions.

Packet Types

• Peer Management:
  • PKT_TYPE_CONNECT_ESTABLISH_REQ and PKT_TYPE_CONNECT_ESTABLISH_RESP for establishing peer connections.
  • PKT_TYPE_GET_PEERLIST_REQ and PKT_TYPE_GET_PEERLIST_RESP for managing the network’s peer list.
• Blockchain Synchronization:
  • PKT_TYPE_GET_BLOCK_HEIGHT_REQ and PKT_TYPE_GET_BLOCK_HEIGHT_RESP for blockchain height synchronization.
  • PKT_TYPE_GET_BLOCK_BY_HASH_REQ, PKT_TYPE_GET_BLOCK_BY_HEIGHT_REQ, and their respective responses for fetching specific blocks.
• Transaction Propagation:
  • PKT_TYPE_INCOMING_MEMPOOL_TRANSACTION for broadcasting new transactions to the mempool.

Message Handling

• Processing Messages:
  • handle_packet() and handle_packet_sendto() manage routing and processing of incoming/outgoing packets.
  • Ensures anonymous connections and version compatibility with enforced checks.
• Serialization:
  • serialize_message() packages messages for transmission.
  • deserialize_message() decodes received packets into actionable messages.

Synchronization Features

• Sync Requests: Initiates synchronization based on block height and ensures backup integrity with init_sync_request().
• Backup and Rollback: Uses backup_blockchain_and_rollback() to ensure blockchain consistency during synchronization.
• Grouped Synchronization: Efficiently synchronizes multiple blocks at once to minimize delays.

Error Handling

Robust error-checking mechanisms handle issues such as corrupted packets, invalid transactions, or failed connections.

Installation Guide

Dependencies

Vulkan includes submodules in the external directory for required dependencies. Precompiled dependencies can be used for faster setup.

Windows

Detailed setup instructions will be provided soon.

macOS

Install the necessary packages using Homebrew:

brew install leveldb
brew install rocksdb
brew install libsodium
brew install json-c

Linux

Install the required dependencies using apt-get:

sudo apt-get install librocksdb-dev
sudo apt-get install libsodium-dev
sudo apt-get install libjson-c-dev

Compilation Instructions

Once dependencies are installed, compile the Vulkan daemon using CMake.

Windows

git clone https://github.com/vulkancurrency/vulkan.git
cd vulkan
git submodule update --init --recursive
mkdir build
cd build
cmake -G "Visual Studio 14 Win64" ..

macOS & Linux

git clone https://github.com/vulkancurrency/vulkan.git
cd vulkan
git submodule update --init --recursive
mkdir build
cd build
cmake .. && make -j 4

ARM MacBook

For ARM-based MacBooks, run:

arch -x86_64 /usr/local/bin/cmake ..
make -j <NUMBER_OF_THREADS>

Forking Guide

Vulkan encourages forking to foster innovation and improve the blockchain.

Steps to Fork

1. Update parameters.h: Modify definitions for testnet or mainnet configurations.
2. Recompile: Build the Vulkan daemon and generate a genesis block.
3. Adjust Configurations: Update the genesis block details in the configuration files.

Example Testnet Genesis Block

Block:
Version: 1
Previous Hash: 0000000000000000000000000000000000000000000000000000000000000000
Hash: 00000000ca2796715a7515bf51295cce6715d6a6dfafe67effab4e2a7798423f
...

How Bitcoin Works

Bitcoin is the foundational cryptocurrency that inspired Vulkan’s development. By understanding Bitcoin’s architecture and limitations, Vulkan was designed to enhance scalability, provide customizable features, and reduce resource consumption. Below is an in-depth explanation of how Bitcoin works.

Overview

Bitcoin operates on a decentralized, peer-to-peer network. Transactions are verified by miners and recorded on a public ledger called the blockchain. Bitcoin’s architecture eliminates the need for central authorities, making it trustless and secure.

Key Components

1. Blockchain: A distributed ledger that records all transactions.
2. Nodes: Computers that participate in the network, maintaining and validating the blockchain.
3. Miners: Nodes that solve cryptographic puzzles to add new blocks to the blockchain.
4. Wallets: Digital tools that store users’ private and public keys, enabling them to send and receive Bitcoin.
5. Transactions: Transfers of Bitcoin between users, verified and added to blocks by miners.
6. Consensus Mechanism: The network’s consensus ensures that all nodes agree on the current state of the blockchain.

Transaction Process

graph LR
    A[User A Sends Bitcoin] -->|Broadcast Transaction| B[Network Nodes]
    B -->|Validation| C[Transaction Pool]
    C -->|Selected by Miners| D[Block Created]
    D -->|Added to Blockchain| E[User B Receives Bitcoin]

Loading

Mining Process

Mining involves solving a computationally intensive problem called a proof of work. This ensures the network’s security and prevents malicious actors from altering the blockchain.

Steps in Mining

graph TD
    A[Pending Transactions] --> B[Form a Block]
    B --> C[Solve Puzzle with Hashing]
    C -->|Puzzle Solved| D[Broadcast New Block]
    D --> E[Validated by Network]
    E --> F[Block Added to Blockchain]

Loading

Security Features of Bitcoin

graph LR
    A[Decentralized Network] --> B[No Single Point of Failure]
    A --> C[Resistant to Censorship]
    D[Proof of Work] --> E[High Computational Barrier]
    F[Blockchain Structure] --> G[Immutable Ledger]

Loading

Applications of Bitcoin

Bitcoin has a wide range of applications, including:

1. Digital Payments: Facilitating peer-to-peer transactions globally.
2. Store of Value: Often referred to as "digital gold," Bitcoin is used as a hedge against inflation.
3. Smart Contracts: Limited capabilities through Layer 2 solutions like Lightning Network.
4. Decentralized Finance (DeFi): Enabling financial services without intermediaries.

License

Vulkan is released under the MIT License. Refer to the LICENSE file for detailed information.