What's the difference between: Verisign Thawte Geotrust Rapidssl certs?

Verisign owns all these certificate issuing companies: Verisign Thawte Geotrust and Rapidssl.

What is the difference between them and why is the price difference so great?

Update: Here are just a couple of differences I've come across:
GeoTrust is not chained: devices that don't properly validate the entire chain may have better luck with this one. I've seen ActiveSync work better with unchained certs than chained certs.

RapidSSL and Geotrust certs are not licensed per server, so that means you can purchase one cert for an entire webfarm.

Verisign certificates come with a free daily malware scan that alerts you if any such software is found on your site.

Only Verisign code signing certificates work with WinQual

Solution 1:

All SSL certificate do two things, authenticate that the holder of the certificate is who they claim to be, and encrypt the communications between client and server.

When you pay more the levels of authentication (i.e. the checks that the certificate authority makes when you go to them to purchase a cert for your website) increase as do the levels of warranty if the CA screws up.

The level of encryption will be no different with a $10 cert (or even a free self-signed one) and a $2000 cert.

Solution 2:

MakerofThings is right, those are the primary differences (I work for VeriSign's EV SSL department). In addition to malware scanning, the VeriSign SSL package is also associated with other trust products, such as the VeriSign checkmark and what's called seal-in-search (where the VeriSign checkmark appears next to your products in shopping search engines like The Find). Verisign, Thawte, Geotrust and Rapidssl all have their specific value and market, but with VeriSign it's more of a "suite" of trust that you're acquiring. Feel free to field any other questions to [email protected].