None
A human entity that is responsible for managing a certificate for the non-human entity identified as the subject in the certificate (e.g., applying for the certificate; generating the key pair; replacing the certificate, when required; and revoking the certificate). Note that a certificate sponsor is also a sponsor of the public key in the certificate and the corresponding private key.
Source(s):
NIST SP 800-57 Part 2 Rev.1
A human entity that is responsible for managing a certificate for the non-human entity identified as the subject in the certificate (e.g., a device, application or process). Certificate management includes applying for the certificate, generating the key pair, replacing the certificate when required, and revoking the certificate). Note that a certificate sponsor is also a sponsor of the public key in the certificate and the corresponding private key.
Source(s):
NIST SP 800-57 Part 1 Rev. 5