What's "revocation checking" about, and does it matter that it's turned off?
When you receive a digitally signed message using Outlook Express 6, you will see the following screen (unless it has been disabled):
When you get past this warning, the digital certificate used to sign the e-mail message is indicated with a red ribbon:
Clicking on this ribbon with allow you to view the details of the certificate. You will likely see a note that "You have turned off revocation checking":
Here's what Outlook Express help has to say about revocation checking:
How do you verify a digital signature?
With revocation checking, you can verify the validity of a digitally signed message. When you make such a check, Outlook Express requests information on the digital ID from the appropriate certification authority. The certification authority sends back information on the status of the digital ID, including whether the ID has been revoked. Certification authorities keep track of certificates that have been revoked due to loss or termination.
However, according to this Microsoft Knowledge Base article:
Beginning with Outlook Express 5.01, certificate revocation checking is disabled by default. If revocation checking is enabled, users with slow connections may experience a long period of inactivity while a certificate's revocation status is checked. This behavior may cause the user to believe that Outlook Express is not working properly.
If revocation checking is disabled you cannot know if a certificate is valid or not: it may have expired, or been revoked (e.g. if the owner believes his or her private key has been compromised, or the certificate contained outdated information). An expired or revoked certificate will cause a security alert.
If you do decide to enable revocation checking, go to Tools > Options > Security > Advanced and select "Only when online" under Revocation Checking, then OK twice.
Revocation checking traditionally depends on the Certificate Authority (CA) issuing a Certificate Revocation List (CRL). Online Certificate Status Protocol (OCSP) is an alternative means of determining the validity of a digital certificate without requiring CRLs. When revocation checking is enabled, the next time you receive a digitally signed e-mail you may see a note that "The digital ID cannot be checked for revocation because a revocation list is not available.", as documented here. However, you will only see this if you actively click on the red ribbon as above, since Outlook Express won't notify you automatically when it can't find a CRL!
For more general information about the use of digital certificates with Outlook Express, try this link.
I WOULD LIKE A LINK THAT WILL TAKE ME TO A CERTIFICATION AUTHORITY TO OBTAIN A DIGITAL ID.
I AM USING MICROSOFT OUTLOOK EXPRESS.
TRY THAWTE FOR A PERSONAL E-MAIL CERTIFICATE.