What does “subject” mean in certificate?

certificatepkix509

The related link is this MSDN article.

I am always confused about the term "subject", for example, sk option
"Specifies the subject's key container location", sr option "Specifies the
subject's certificate store location". What exactly does subject mean here? The
certificate owner? The certificate issuer (e.g. the root CA which issues the
certificate)? Or something else?

Best Solution

The Subject, in security, is the thing being secured. In this case it could be a person's email or a website or a machine.

If we take the example of an email, say my email, then the subject key container would be the protected location containing my private key.

The certificate store usually refers to the Microsoft certificate store which contains certificates form trusted roots, machines on the network, people etc. In my case the subjects certificate store would be the place, within this store, holding my certificates.

If you are working within a Microsoft domain then the subject name will invariably hold the Distinguished Name, of the subject, which is how the domain references the subject and holds it in its directory. e.g. CN=Mark Sutton, OU=Developers, O=Mycompany C=UK

To look at your certificates on a Microsoft machine:-

Log in as you
run>mmc
Select File>add/remove snap-in and select certificates then select my user account
click Finish then close then ok.
Look in the personal area of the store.

In the other areas of the store you will see the other trusted certificates used to validate signatures etc.