Interworking Public Key Certification Infrastructure

for Commerce, Administration and Research

Secure Video Conferencing


You will need to download the following University College London Video Conferencing software as well as the PGP software:

SDR Announcement Tool v2.7e or later Details Download Site Must be Experimental Version
RAT Audio Tool v3.0.28 or later Details Download Site -
VIC Video Tool v2.8 or later Details Download Site -
NTE Text Tool v1.7.0 or later Details Download Site -
WBD Whiteboard Tool v1.0 or later Details Download Site -
PGP Pretty Good Privacy v2.6.3i (not later) Details Download Site Later versions not yet supported

In addition, if you are outside the US, your version of Netscape will probably have weakened encryption to comply with US export regulations. You can download the full-strength Netscape, as well as other full-strength cryptography products, from the site below.

Application Unix/Win32/Mac/etc
Miscellaneous (including US strength Netscape) (formerly Replay)

Setting Up

The above software should be installed. For the UCL tools the windows versions are generally self-extracting and the Unix versions usually need to be unzipped (although Netscape can strip off the trailing .gz from the filename which can lead to confusion). You should ensure that the binaries are on your PATH.

You should then set up an environment variable PGPSTATE and ensure this is set to 1. This will enable the use of PGP authentication/encryption in SDR.

If you do not already have a PGP keypair you should generate one with PGP. This can be done by typing "pgp -kg" and following the instructions.

Using SDR with Public Key Cryptography

The first thing you need to do is to make your PGP public key available to other users of SDR in order that they can authenticate any announcements you make and sign with your private key. We have a server at UCL where your public key can be stored. You should do the following:

Group managers, that is people who have added a PGP public key to the database, can then create/manage groups. Any member they add to a group can access the group page and download the group Public/Private key pair. This can be added to each user's PGP keyfile(s) if they run the command "pgp -ka". Once a user has installed both the private and public group key into their PGP keyrings they can then make encrypted SDR announcements by selecting the group key from the SDR create session window. Any other member of the group can decrypt these announcements but other users will be unable to read them. Users should sign any announcements they make with their own Private key (rather than the group private key) so that other users can be sure of its authenticity. Any user who has downloaded the announcers public key will be able to authenticate the session announcement.


Bug reports should be sent to

This is a first draft of the instructions. If you find anything unclear or have any queries/comments/suggestions please mail them to the above mailing list (

Last modified by on Saturday 17th July 1999.