Blockchain Implementation (Sample Demo)

This is my solution of Blockchain implementation for the fulfillment of Assignment-1 of the course Introduction to Blockchain (Instructor : Dr. Debashis Das; Run : Fall 2022).

Miner(s)

For adding Miner(s), follow these steps :

• Copy and paste any of the Miners' folder and edit the Miner_x.py file in the appropriate places. Replace x with suitable number.
• Remove all Users and Transactions from users.json and transactions.json files respectively. Keep the all_users.json and blockchain.json unchanged.
• Make necessary changes in Miner's number in verify_chain_thread.py file.

Leader Selection

For leader selection, a separate leader_selection_thread.py has been written. Run this program in a separate Terminal/CMD and leave it running infinitely. The main functionalities of this code are -

• Initialize Leader Miner
• Collect all unrecorded transactions in the whole network
• Mine block by following all protocols (e.g. proper PoW, timestamp etc.)
• Get the block verified from other Miners
• If the acceptance is more than 75%, add the block in the blockchain

User Operations

This is a Menu Driven code from the perspective of an End User. The user has to register using a unique username and use that to perform various operations (mainly, transactions with other users in the network) through this.

Instructions for Execution

• Open one terminal/CMD for each of the Miners and start executing verify_chain_thread.py. This will keep on verifying the existing blockchain for malicious/altered blocks at a certain interval.
• Open one terminal/CMD and start executing leader_selection_thread.py. This will keep on assigning Mining workload on each of the miners in a sequential manner.
• Open a Terminal/CMD and start executing UserOperations.py. From here, you can register yourself as a user. Add multiple users in the network and perform some transactions. You can see the changes to be reflected on the corresponding files inside Miners' folders.

Instructions for Assignment-2

This is a continuation of Assignment-1. Here, one needs to find certain values from the blockchain network created in Assignment-1.

• Open one terminal/CMD and run A2.py.
• For Q3, you need to enter a valid hash of a block.
• Executing the script will produce necessary outputs.