区块链在医疗数据管理中的应用：安全与隐私的新纪元

import hashlib
import json
from time import time

class Blockchain:
    def __init__(self):
        self.chain = []
        self.current_transactions = []
        self.new_block(previous_hash='1', proof=100)

    def new_block(self, proof, previous_hash=None):
        block = {
            'index': len(self.chain) + 1,
            'timestamp': time(),
            'transactions': self.current_transactions,
            'proof': proof,
            'previous_hash': previous_hash or self.hash(self.chain[-1]),
        }
        self.current_transactions = []
        self.chain.append(block)
        return block

    def new_transaction(self, patient_id, data):
        self.current_transactions.append({
            'patient_id': patient_id,
            'data': data,
        })
        return self.last_block['index'] + 1

    @staticmethod
    def hash(block):
        block_string = json.dumps(block, sort_keys=True).encode()
        return hashlib.sha256(block_string).hexdigest()

    @property
    def last_block(self):
        return self.chain[-1]

# 创建区块链实例
blockchain = Blockchain()

# 添加新的医疗数据交易
blockchain.new_transaction(patient_id='12345', data='Patient medical data')

# 挖掘新块
last_block = blockchain.last_block
proof = 101  # 简单示例，实际应用中需要复杂的工作量证明算法
blockchain.new_block(proof)

# 打印区块链
print(json.dumps(blockchain.chain, indent=4))