How to use key for web server

[Raja Saha]

Hello,

How can I implement key-pair communication between apache and client? I
want the user to identify the key they want to use, by email id or
fingerprint. Then all further transactions will be excrypted using the
server-client key pair. 

The sequnce will be;

* User gives info to search key
* Apache uses that info to look up key on gpg key server
* Apache sends next page (eg. log-in) using key-pair encryption
* Client if they can decrypt and view further communication on web-
browser, continues session.

How can I do this on server-side, what browser extention do I need on
client-side?

Thanks for your help.

Sincerely,
Raja