I was reading this article about how the Server Authentication is being done During SSL Handshake https://docs.oracle.com/cd/E19693-01/819-0997/aakhc/index.html
I do understand everything but I have a specific question about the point number 3 when it says
if the CA certificate’s public key doesn’t correspond to the private key used by the CA to sign the server certificate, the client won’t authenticate the server’s identity.
How using only the public key we know that this public key does not correspond to the private key? do we use the public key to decrypt the signature and make sure it matches some data sent along with the signature?
Thanks in advance