For some context, this was the first successful effort do deobfuscate Skype protocol. Many tried before, and after.

The most remarkable thing is their idea of what they call "Twin processes debugging", which is: debug one process, but use the other one to count checksums which are checked randomly in runtime.

On the same subject is this recording of a talk by Desclaux (co-author of these slides) and Kortchinsky presented at REcon 2006.

https://archive.org/details/Fabrice_Desclaux_and_Kostya_Kort...

Slides and other files from that presentation can be found here: http://2006.recon.cx/en/f/

What do privacy-conscious people use for video conferencing these days?

Face to face meetings?