Immutable Ledger

1. Introduction

An immutable ledger is a fundamental feature of blockchain technology, ensuring that once data is recorded, it cannot be altered or deleted. This attribute enhances security and trust in digital transactions.

2. Key Concepts

3. How It Works

The process of maintaining an immutable ledger involves several key steps:

1. Transaction Initiation: A transaction is requested by a user.
2. Transaction Verification: Nodes in the network verify the transaction.
3. Consensus: The transaction is added to a block once a consensus is reached.
4. Block Addition: The new block is added to the blockchain.
5. Immutability: The block is cryptographically linked to the previous block, making it immutable.

Below is a flowchart illustrating this process:

graph TD;
    A[Transaction Initiation] --> B[Transaction Verification]
    B --> C[Consensus]
    C --> D[Block Addition]
    D --> E[Immutability]
            

4. Code Example

Here’s a simple example of how to create a block in a blockchain using Python:

class Block:
    def __init__(self, index, previous_hash, timestamp, data, hash):
        self.index = index
        self.previous_hash = previous_hash
        self.timestamp = timestamp
        self.data = data
        self.hash = hash

    def __repr__(self):
        return f"Block(index={self.index}, hash={self.hash})"

# Example of creating a new block
new_block = Block(1, "0", "2023-10-01", {"amount": 100}, "hash_value_here")
print(new_block)
                

5. Best Practices

• Use strong cryptographic algorithms.
• Regularly update and patch blockchain nodes.
• Implement robust access controls.

6. FAQ