How securily is the Private key generated: Free Secure Email Cert

Dear Forum, dear Comodo,
We would very much like to test the Free Secure Email Certificate (S/MIME) for use with our email clients, first for private use, later maybe to be included in our company.

Now one very simple security question:
When we create the Free Secure Email Certificate (S/MIME) using your website (with I-Exlorer or Firefox on Windows 7):

Is at any point (e.g. during the creation or at any time later) the generated private key sent somewhere (e.g. to Comodo) outside my own computer, or does it always and only remain on my computer?

As far as we understand this is done within the browser.

But does this mean that the private key NEVER EVER leaves our computer?

I think this is important to know and should be included in your Information/Frequently Asked Questions!

We would be happy if you could clarify and give some proof, so we could forward that to our IT dpt.

Thank you very much in advance!


I can tell you that Comodo ‘never ever’ see the Private Key.
Only the computer you make the application from has that.
Comodo get the Public Key, that’s what they sign and you collect.



This might help: