PSI的python 实现
时间: 2024-05-03 10:18:49 浏览: 8
PSI(Private Set Intersection)是一种保护隐私的协议,用于计算两个集合的交集,同时不泄露两个集合的任何信息。以下是一个基于Python的PSI实现示例:
```python
import hashlib
import random
def generate_random_bits(n):
return [random.getrandbits(1) for _ in range(n)]
def hash_to_bytes(value):
return hashlib.sha256(str(value).encode()).digest()
def generate_hashed_set(data):
return set(hash_to_bytes(datum) for datum in data)
def intersection_size(set1, set2):
return len(set1 & set2)
def private_set_intersection(set1, set2):
hashed_set1 = generate_hashed_set(set1)
hashed_set2 = generate_hashed_set(set2)
intersection_bits = [0] * len(hashed_set1)
# Alice chooses random bits and sends them to Bob
alice_bits = generate_random_bits(len(hashed_set1))
# Bob hashes his set and compares it with Alice's bits
for index, hashed_value in enumerate(hashed_set2):
if hashed_value in hashed_set1:
intersection_bits[list(hashed_set1).index(hashed_value)] = 1
# Bob calculates the intersection size
intersection_size = sum(intersection_bits)
# Alice calculates the intersection size using her bits
alice_intersection_size = sum([alice_bits[i] & intersection_bits[i] for i in range(len(hashed_set1))])
# Bob receives Alice's bits and calculates the intersection size
bob_intersection_size = sum([alice_bits[i] & intersection_bits[i] for i in range(len(hashed_set1))])
# Check if both parties got the same intersection size
assert alice_intersection_size == bob_intersection_size
return intersection_size
```
这是一个简单的PSI实现,只用了SHA-256哈希函数。在实际应用中,可以使用更复杂的哈希函数和其他技术来提高安全性和隐私保护。