<story><title>How to build large-scale end-to-end encrypted group video calls</title><url>https://signal.org/blog/how-to-build-encrypted-group-calls/</url></story><parent_chain></parent_chain><comment><author>JoeAltmaier</author><text>Oh this all brings back memories, of Sococo in the 2000&amp;#x27;s. We faced all these problems and had similar solutions to them all.&lt;p&gt;We even had a rapidly adapting network make-and-break recovery layer. You unplug your laptop from a wired connection, switch to wireless - we recovered in milliseconds. You heard barely a click.&lt;p&gt;The encryption issue is fun - we had a rotate-key message in-band. The receiver loaded new keys and tried them in sequence to ease the turnover time - out-of-order packets etc could make it ambiguous for a short while which key to use. A cache and aging keys out made it work pretty well.&lt;p&gt;Remixing on user stations proved to be problematic (mentioned elsewhere on this thread). You&amp;#x27;d think if 6 people at one site were conferencing with a dozen elsewhere, you could elect one at each site to mix-and-forward. But corporate networks made it hard to determine who was &amp;#x27;adjacent&amp;#x27; - they were often layered and without uPNP (is that what the router protocol is called?) you couldn&amp;#x27;t tell if somebody at the next desk was even in your company.&lt;p&gt;We had up to 100 people in a conference, and our enter-the-conference time was on the order of 100ms. Click into an all-hands, and be able to hear everybody before you finger left the mouse button. It was wonderful.&lt;p&gt;Sococo today is a sad shadow of that. They went open-source and lost all our IP instantly. Just another WebRTC client last I knew.</text></comment>
<story><title>How to build large-scale end-to-end encrypted group video calls</title><url>https://signal.org/blog/how-to-build-encrypted-group-calls/</url></story><parent_chain></parent_chain><comment><author>johnisgood</author><text>Great, now they should just stop using telephone numbers as identifiers.</text></comment>