ApexChain - A Java-Based Blockchain Implementation

ApexChain is a simple blockchain implementation in Java that simulates wallet creation, transactions, and block mining. It demonstrates the core concepts of blockchain technology, including cryptographic signatures, proof-of-work, and transaction validation.

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Features

• Wallet Creation: Generate public and private keys using Elliptic Curve Cryptography (ECC).
• Transactions: Send funds between wallets with secure cryptographic signatures.
• Block Mining: Mine blocks using a proof-of-work algorithm (hash with leading zeros).
• UTXO Model: Track unspent transaction outputs (UTXOs) to validate transactions.
• Blockchain Validation: Verify the integrity of the blockchain by checking block hashes and transaction signatures.

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How It Works

1. Genesis Block: The first block in the blockchain is created with an initial transaction.
2. Wallets: Users can create wallets, which generate public and private key pairs.
3. Transactions: Wallets can send funds to each other by creating and signing transactions.
4. Mining: Transactions are added to blocks, which are mined by solving a proof-of-work problem.
5. Validation: The blockchain is validated by checking the integrity of each block and its transactions.

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Getting Started

1. Clone the repository:

   git clone https://github.com/your-username/ApexChain.git

2. Navigate to the project directory:

   cd ApexChain

3. Compile and run the project:

   javac ApexChain.java
   java ApexChain

Project Structure

• ApexChain.java: Main class to run the blockchain simulation.
• Wallet.java: Handles wallet creation and transaction signing.
• Block.java: Represents a block in the blockchain.
• Transaction.java: Handles transactions between wallets.
• StringUtil.java: Utility class for cryptographic operations (SHA-256, ECDSA).

Technologies Used

• Java: Core programming language.
• BouncyCastle: Cryptographic library for ECC and SHA-256.
• SHA-256: Hashing algorithm for block hashes.
• ECDSA: Elliptic Curve Digital Signature Algorithm for transaction signing.

Future Improvements

• Add a graphical user interface (GUI) for better user interaction.
• Implement a peer-to-peer network for decentralized blockchain.
• Add support for smart contracts.
• Improve transaction validation and error handling.

Contributing

Contributions are welcome! If you'd like to contribute, please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bug fix.
3. Commit your changes.
4. Submit a pull request.

Contact

For questions or feedback, feel free to reach out:

• Email: amitk.vishwa1633@gmal.com
• GitHub: (https://github.com/Mit16)

Commit and Push Your Changes

1. Open your terminal or command prompt.
2. Navigate to the repository folder.
3. Run the following commands to add, commit, and push your changes:

   git add .
   git commit -m "Initial commit: Added ApexChain project files and README"
   git push origin main