CA-signed Certificate
This is a certificate signed by the CA (Certificate Authority.) You can obtain it to apply to the Certificate Authority. This certificate certifies the existence of the printer is and used for SSL/TLS communication so that you can ensure the safety of data communication.
When it is used for SSL/TLS communication, it is used as a server certificate.
When it is set to IPsec/IP Filtering, IEEE802.1x communication, or S/MIME, it is used as a client certificate.
CA Certificate
This is a certificate that is in chain of the CA-signed Certificate, also called the intermediate CA certificate. It is used by the web browser to validate the path of the printer's certificate when accessing the server of the other party or Web Config.
For the CA Certificate, set when to validate the path of server certificate accessing from the printer. For the printer, set to certify the path of the CA-signed Certificate for SSL/TLS connection.
You can obtain the CA certificate of the printer from the Certification Authority where the CA certificate is issued.
Also, you can obtain the CA certificate used to validate the server of the other party from the Certification Authority that issued the CA-signed Certificate of the other server.
Self-signed Certificate
This is a certificate that the printer signs and issues itself. It is also called the root certificate. Because the issuer certifies itself, it is not reliable and cannot prevent impersonation.
When using for SSL/TLS communication
Use it when making the security setting and performing simple SSL/TLS communication without the CA-signed Certificate.
If you use this certificate for an SSL/TLS communication, a security alert may be displayed on a web browser because the certificate is not registered on a web browser.
When setting to S/MIME
You can also use a self-signed certificate instead of a CA-signed certificate. You can use S/MIME functions without the cost of obtaining a CA-signed certificate, for example in a network environment that does not have an external connection (Internet connection), such as an enterprise network. However, it is recommended to use a CA-signed certificate when using external connections because a self-signed certificate is low-security.