It seems like you're experimenting with quantum-resistant cryptography using Python and the ecdsa and pqcrypto libraries. Your code snippet demonstrates the generation of classical and quantum key pairs, signing, and verifying messages. However, there are a few issues with your code that I'd like to point out:
- Base64 Encoding: The way you're encoding the header and payload using
base64.urlsafe_b64encode is incorrect. The urlsafe_b64encode function returns a bytes object, and you're trying to decode it as a string, which will raise an error. You should decode the bytes object to a string using .decode().
- JWT Message Format: The message format you're using for the JWT is not standard. The
typ parameter is not set correctly, and the aim parameter is not valid. A correct JWT header might look like this: {"alg": "ES256+SPHINCS+", "typ": "JWT"}.
- Key Pair Generation: The
generate_keypair function from pqcrypto is used to generate a quantum key pair, but you're also using SigningKey.generate from ecdsa to generate a classical key pair. Make sure you're using the same key pair for both classical and quantum cryptography.
Here's a corrected version of your code snippet:
import base64
import hashlib
from ecdsa import SigningKey, SECP256k1
from pqcrypto.sign.sphincsplus import generate_keypair, sign, verify
# Generate classical and quantum key pairs
sk_classical = SigningKey.generate(curve=SECP256k1)
pk_classical = sk_classical.get_verifying_key()
sk_quantum, pk_quantum = generate_keypair()
# Example header and payload (Base64 encode them)
header = '{"alg":"ES256+SPHINCS+","typ":"JWT"}'
header = base64.urlsafe_b64encode(header.encode()).decode().strip("=")
payload = '{"sub":"Scot Ringa","name":"Scot Ringa","role":"admin","permissions":["energy-transaction","carbon-offset","blockchain-edit"],"iat":1617270399,"exp":1617875199}'
payload = base64.urlsafe_b64encode(payload.encode()).decode().strip("=")
# Create unsigned JWT message
unsigned_message = f"{header}{payload}"
# Sign the message using the classical key pair
sk_classical = SigningKey.generate(curve=SECP256k1)
sk_classical = sk_classical.to_bytes(32, 'big')
sk_classical = base64.urlsafe_b64encode(sk_classical).decode().strip("=")
pk_classical = base64.urlsafe_b64encode(pk_classical.get_verifying_key().to_bytes(32, 'big')).decode().strip("=")
# Verify the signature using the quantum key pair
sk_quantum, pk_quantum = generate_keypair()
sk_quantum = base64.urlsafe_b64encode(sk_quantum).decode().strip("=")
pk_quantum = base64.urlsafe_b64encode(pk_quantum).decode().strip("=")
# Sign the message using the classical key pair
signature = sign(sk_classical, unsigned_message.encode())
signature = base64.urlsafe_b64encode(signature).decode().strip("=")
# Verify the signature using the quantum key pair
try:
verify(pk_quantum, signature.encode(), unsigned_message.encode())
print("Signature is valid.")
except:
print("Signature is invalid.")
Please note that the above code is for demonstration purposes and might not work as is. You'll need to adjust it to fit your specific use case and ensure that you're using the correct key sizes and encoding formats.
4/1/2025 04:49pm
