This program simulates the core functionalities of a blockchain system. It allows you to create and manage transactions, mine blocks with a specified difficulty, and view the current state of the blockchain, transactions and wallets. The blockchain is represented using a Merkle tree to ensure data integrity and security.

• Transaction Management: Add transactions between different wallets.
• Block Mining: Mine new blocks with a customizable difficulty level.
• Blockchain Display: Print the current state of the blockchain, including details of each block.
• Wallet Management: View the balances and transaction history of each wallet.
• Transactions Managment: View transaction history in the Blockchain.

• Python 3.x
• pandas library
• colorama library

You can install the required libraries using:

pip install pandas colorama

To run the program, follow these steps:

1. Open the Colab Notebook: Click on the link to open the notebook in Google Colab.
2. Execute Cells: Run each cell in the notebook sequentially. This will set up the blockchain environment and make the program ready for interaction.
3. Interact with the Program: Once the setup is complete, you can start using the program by following the menu options provided.

After starting the program, you will be presented with a menu with the following options:

1. Add Transaction:

   • Description: Add a new transaction to the blockchain.
   • Inputs Required: Sender's name, receiver's name, and the amount to be transferred.

2. Mine Block:

   • Description: Mine a new block with the pending transactions.
   • Inputs Required: Mining difficulty, which determines the number of leading zeros required in the block hash.

3. Print Blockchain:

   • Description: Display the details of each block in the blockchain.
   • Details Shown: Nonce, root hash, previous hash, and block hash.

4. Print Wallets:

   • Description: Show the current state of each wallet.
   • Details Shown: Wallet name, balance, and last transaction ID.

5. Print Transactions:

   • Description: Show transactions that have been added to the Blockchain, along with the corresponding block in which each transaction is stored.
   • Details Shown: id, from, to, refundTo, amount, block ID.

6. Exit:

   • Description: Exit the program.

• Hash Calculation: get_hash(dato) calculates the SHA-256 hash of the input data.
• Merkle Tree Construction: build_merkle_tree(info) constructs a Merkle tree to summarize the transactions in a block.
• Block Mining: mintBlock(data, min) mines a new block by finding a nonce that meets the difficulty requirement.
• Transaction Checking: checkTransaction(data) verifies and processes a transaction, updating the relevant wallets.
• Printing Information: print_network(), print_wallets() and print_transactions() display the blockchain, wallet and transactions information respectively.

• Adding a Transaction:

  • Input: Sender: Juan, Receiver: Esteban, Amount: 10
  • Output: Transaction completed successfully.

• Mining a Block:

  • Input: Difficulty: 2
  • Output: Block successfully mined.

• Printing transactions

  • Output: Displays all transactions that have been added to the Blockchain so far.

• Printing Blockchain:

  • Output: Displays the details of each block.

• Printing Wallets:

  • Output: Displays the current state of all wallets.