Comment by hilbert42

"…I saw already Bruce Schneider's blog some team proof of concept where they listened using laptop speakers what was spoken in that room."

Users need to know the electrical features of their H/W and its limits. If a loudspeaker output stage is designed (hardware wired) so that it can never act as an input then no later firmware update can turn the speaker into a microphone.

This is why hardware authentication is becoming more and more important.

limits