Python实现DSA算法

DSA（Digital Signature Algorithm）是一种数字签名算法，用于确保数据的完整性、证和不可否认性。下面是一个使用Python实现DSA算法的示例代码：

import hashlib
import random

def generate_key(p, q, g):
    x = random.randint(1, q-1)
    y = pow(g, x, p)
    return (x, y)

def sign_message(message, p, q, g, x):
    h = int(hashlib.sha1(message.encode()).hexdigest(), 16)
    k = random.randint(1, q-1)
    r = pow(g, k, p) % q
    s = (pow(k, -1, q) * (h + x * r)) % q
    return (r, s)

def verify_signature(message, signature, p, q, g, y):
    r, s = signature
    if r < 0 or r > q or s < 0 or s > q:
        return False
    h = int(hashlib.sha1(message.encode()).hexdigest(), 16)
    w = pow(s, -1, q)
    u1 = (h * w) % q
    u2 = (r * w) % q
    v = ((pow(g, u1, p) * pow(y, u2, p)) % p) % q
    return v == r
# 示例用法
p = 1279
q = 383
g = 7

# 生成密钥对
x, y = generate_key(p, q, g)

# 待签名的消息
message = "Hello, world!"

# 对消息进行签名
signature = sign_message(message, p, q, g, x)