Certificates can be obtained from one of the following:
Well-known Certificate Authority (CA)
Create a certificate request, then obtain and store a server certificate from one of the pre-defined (well-known) CAs. This procedure requires the least setup because the Z and I Emulator for Web key database files already include the root certificates of several CAs.
Create a certificate request, then obtain a server certificate and a root certificate from a CA that does not have its root certificate already included in the database. Having obtained the certificates, you must store them in the key database files.
You can create a certificate and use it while you are waiting for a CA's certificate, which can take some time. If you think the self-signed certificate provides adequate security, you can use it permanently.