区块链是什么技术

import hashlib
import time

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

    def calculate_hash(self):
        block_string = str(self.index) + str(self.timestamp) + str(self.data) + str(self.previous_hash)
        return hashlib.sha256(block_string.encode()).hexdigest()

class Blockchain:
    def __init__(self):
        self.chain = [self.create_genesis_block()]

    def create_genesis_block(self):
        return Block(0, "Genesis Block", "0")

    def add_block(self, new_block):
        new_block.previous_hash = self.chain[-1].hash
        new_block.hash = new_block.calculate_hash()
        self.chain.append(new_block)

# 示例使用
my_blockchain = Blockchain()
my_blockchain.add_block(Block(1, "First Block", ""))
my_blockchain.add_block(Block(2, "Second Block", ""))

for block in my_blockchain.chain:
    print(f"Index: {block.index}")
    print(f"Data: {block.data}")
    print(f"Hash: {block.hash}")
    print(f"Previous Hash: {block.previous_hash}")
    print("\n")