Answer:
private key
Step-by-step explanation:
For an enterprise that uses smart cards for strong user authentication, a digital certificate needs to be issued to the smart card. This digital certificate is used to identify the user and the infrastructure that does that is known as PKI (Public Key Infrastructure). PKI involves the use of a public key that is accessible to everyone and a private key that is stored on the card. Encrypted information on one key can only be decrypted by the other key, and vice versa This is to suggest that it is a transitive process. Therefore, since PKIs depend heavily on private keys, I should use private keys and keep these keys safe and secure since only the intended user have access to them.