RSA Signatures, Python and Hazmat
At the core of digital trust is the usage of digital signatures. With this, we can verify the creator of the data, and also that it has not been modified. We do this using public-key encryption, and in this article, we will look at how we can use the hazmat (Hazardous Material) primitives in the Python cryptography library.
With public-key encryption, we create a key pair: a public key and a private key. If Alice is sending data to Bob, she can add her digital signature, and which will prove that she is the sender and also verify that the data has not been changed. She does this by signing the data with her private key, and then Bob can prove the signature with Alice’s public key. In this example, we will use RSA keys to sign a message, and then verify the correct signature, but verify that an incorrect signature will fail.
To generate a key we can simply add:
private_key = rsa.generate_private_key(public_exponent=65537,key_size=size)and where size is the number of bits in the public modulus (N), and the public_exponent is typically the value of 65,537. This will then generate a private key and a public key. To extract the public key we can…
