Note that these authentication, non-repudiation etc. properties rely on the secret key prior to its usage. Public revocation of a key-pair is a required ability, else leaked secret keys would continue to implicate the claimed owner of the key-pair. Checking revocation status requires an "online" check; e.g., checking a certificate revocation list or via the Online Certificate Status Protocol. Very roughly this is analogous to a vendor who receives credit-cards first checking online with the credit-card issuer to find if a given card has been reported lost or stolen. Of course, with stolen key pairs, the theft is often discovered only after the secret key's use, e.g., to sign a bogus certificate for espionage purpose.
Note that these authentication non-repudiation etc properties rely on the secret key prior to its usage Public revocation of a key-pair is a required ability else leaked secret keys would continue to implicate the claimed owner of the key-pair Checking revocation status requires an "online" check; eg checking a certificate revocation list or via the Online Certificate Status Protocol Very roughly this is analogous to a vendor who receives credit-cards first checking online with the credit-card issuer to find if a given card has been reported lost or stolen Of course with stolen key pairs the theft is often discovered only after the secret key's use eg to sign a bogus certificate for espionage purpose