Why would an attacker with access to the private key specify a signature creation date after key expiry? They can specify whatever date they want. >Had you fai

Why would an attacker with access to the private key specify a signature creation date after key expiry? They can specify whatever date they want. >Had you failed to notice a key expiration from the 80s, you would assume the signature is valid ... If the algorithm is broken then the implementation should not support verification using that algorithm no matter the expiration date. An attacker can update the key's expiration date to whatever they want if the algorithm is broken.