How to ensure security for web conferencing - a checklist
Ascertain the security need of the meeting. If sensitive business critical topics like merger, acquisition, new product plan is going to be discussed stringent security measures need to be taken.
In this your security policy of your company is more important. It's difficult for hackers to get access to internal IT infrastructure if it's protected by proper firewall. If CEO and CFO are frequently using web conferencing, you can even use the servers, which are hosted, in DMZ zone. Other words, avoid using public network.
Security policy of your company is very important in combat against spam and identity theft. Send details of conference call time and web URL for the conference to all participants. Access to the conference equipment should be password protected. All participants should register their name using unique secret code aka PIN code. There should be a standard operating procedure for userid and password management. IT administrator of your company should change the password frequently.
It's advisable to use "do not copy" and "do not forward" feature of Lotus note to maintain maximum security. If you don't have lotus note, talk your email administrator to find the way the same can be achieved in your mail server.
Hackers can also use parallel devices to intercept your massage during transmission. Hence, at the minimum you should use SSL. There are several sophisticated tools available in market to protect and monitor traffic. If you are working with some third party conference call providers, you must check all the security measures of conference call service providers. Web Conference assures the privacy and integrity of your meetings through the exclusive use of HTTPS to encrypt all meeting content.
It is highly recommended not to display extremely sensitive information during web conference. You should avoid downloading your proprietary info to other's server. If at all it is necessary, please make it a habit to delete the file immediately after completion of the call.

From: http://www.conferencecallaudiovideo.info/webconferencing.php