password protected stream [multicast/unicast]

[woj]

Hi.

I am using vlc to stream mpeg4 video files to end-users via multciast rtp-stream.

I wonder - is there possibility to secure the stream, and allow watching only for specific group of people.
I know how multicast work, in my network there is many "dump" switches, so multicast is literally broadcast (in II layer OSI) - anyone can sniff packets.
In unicast stream there is no problem - vlc can stream to specific ip, or can protect files with password in http stream mode.

The challange is multicast - it rtp mode viewer must have *.sdp file. My idea was to give access to sdp only for people with permission. I can check at streaming server access log and get information: who tries to download sdp and decide to allow it or not.
It will work if people will watch stream getting sdp from vlc server. But if someone simply wget sdp file and give it to his friend (offline) - I have no information abut watching clients.

My questions are:
1. Can be rtp stream played without sdp?
2. Can anybody guess sdp params (by sniffing multicast traffic) and watch stream without sdp? Or build his own sdp?
3. Have you got any other ideas? How to send password/key protected multicast?

I know that multicast is designed to serve open services, but if I want to stream some confidential information for group of people? I don't want discussion about reasons of my question.

best regards

[Sigmund]

1. some can, some can't
2. I wouldn't say anybody can do it, but I'm quite sure sombody could. (at least if they allready get the packets)
3. I think sdp has some fields for keys etc for "safe" encrypted streams, but I don't think vlc implement any of it.

[ZerBit]

You could use Socket Secure Layer to transmit the data that you must protect as SmartSight does.

Regards

[woj]

How? any open project that can do that?

thanks for reply

[ZerBit]

You could see Apache source code, openSSL, ...

I only use SSL from code with ACE&TAO libs.

Regards.