Python implements digital signature, with complete source code

Python implements digital signature, with complete source code

Digital signature is an important technology widely used in modern communication systems. It can ensure the integrity of information, authenticate the sender's identity and protect data from tampering. In Python, we can implement digital signatures by using the hashlib and cryptography libraries.

First, we need to generate a public-private key pair and share the public key with those who need to verify it. Here we use the RSA algorithm to generate a key pair:

from cryptography.hazmat.primitives.asymmetric import rsa, padding
from cryptography.hazmat.primitives import serialization, hashes

# Generate private/public key pair
private_key = rsa.generate_private_key(
    public_exponent=65537, key_size=2048
)
public_key = private_key.public_key()

# Serialize the public key to send to someone else
pem_public_key = public_key.public_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PublicFormat.SubjectPublicKeyInfo
)

# Save private key as PEM file
pem_private_key = private_key.private_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PrivateFormat.PKCS8,
    encryption_algorithm=serialization.NoEncryption()
)
with ope