将下面代码修改成正确格式 import random def gcd(a, b): if b == 0: return a else: return gcd(b, a % b) def mod_inverse(a, m): for x in range(1, m): if (a*x) % m == 1: return x return None def blind_sign(m, n, e, d): # Generate random value r r = random.randint(1, n-1) while gcd(r, n) != 1: r = random.randint(1, n-1) # Blind message m_blind = (m * pow(r, e)) % n # Sign blinded message s_blind = pow(m_blind, d) % n # Unblind signed message s = (s_blind * mod_inverse(r, n)) % n return s # Example usage n = 3233 # modulus e = 17 # public exponent d = 2753 # private exponent m = 1234 # message to be signed s = blind_sign(m, n, e, d) print("Message:", m) print("Signature:", s)

修改后的代码格式如下：

import random

def gcd(a, b):
    if b == 0:
        return a
    else:
        return gcd(b, a % b)

def mod_inverse(a, m):
    for x in range(1, m):
        if (a*x) % m == 1:
            return x
    return None

def blind_sign(m, n, e, d):
    # Generate random value r
    r = random.randint(1, n-1)
    while gcd(r, n) != 1:
        r = random.randint(1, n-1)
        
    # Blind message
    m_blind = (m * pow(r, e)) % n
        
    # Sign blinded message
    s_blind = pow(m_blind, d) % n
        
    # Unblind signed message
    s = (s_blind * mod_inverse(r, n)) % n
        
    return s

# Example usage
n = 3233  # modulus
e = 17    # public exponent
d = 2753  # private exponent

m = 1234  # message to be signed

s = blind_sign(m, n, e, d)

print("Message:", m)
print("Signature:", s)