Yubico Forum

Hi, first post here

I am using SMIME certificate on Yubikey for a year now. Now i need to exchange it for a renewed one. Two questions I have:

1. Why in all docs it says that "certificate" is on the yubikey, nothing about "private key", even though it also is there? Is the term "certificate" used for a package of public+private key, not only public one?
2. How do I save new smime cert while retaining the old one for stored mail decryption?

Cheers!