Abstract: Systems and methods for using cryptographic keys read an existing digital certificate from a hardware cryptographic device and extract a public key from the existing digital certificate. A certificate request message is generated that identifies a new usage and/or certificate field associated with the public key. The certificate request message is signed and communicated to a certification authority. A new digital certificate is received from the certification authority that includes the new usage/field. The new digital certificate is then applied to cryptographic operations, such as signing procedures, encryption procedures and so forth using the existing key pair.