How Respondus Detects Other Devices on Mac
Respondus LockDown Browser scans for "other devices" before and during the exam: external monitors, virtual machines, screen recorders, and certain peripherals. The scan is mostly process-name and OS-API based.
Pre-launch, Respondus enumerates running processes and compares against an internal blocklist (OBS, ScreenFlow, Camtasia, etc.). It calls IOKit to count attached displays (multi-monitor flag). It probes sysctl for hypervisor flags (VM detection). It may also enumerate Bluetooth peripherals and USB devices for some configurations. None of these touch screen content. LDBypass is not a recorder, uses a per-build randomized identity (e.g., SystemDiagnostics, NetworkService) so process-name match fails, and does not require virtualization. The overlay's actual invisibility to capture is a separate mechanism (window privacy) that Respondus cannot probe for.
Key points
- Process enumeration: matches against blocklist of recorders.
- Display count via IOKit: blocks multi-monitor.
- Hypervisor flag check: blocks VMs.
- LDBypass uses randomized identity per build.
- Window privacy flag is invisible to all of Respondus' probes.
Common questions
Does Respondus check the App Store for installed apps?
No. It enumerates running processes only.
Can I rename LDBypass to avoid the blocklist?
Each LDBypass build already has a random innocuous name. You do not need to rename manually.
Does Respondus report what it found to my professor?
It blocks launch and shows you a dialog. Most do not auto-report to the instructor; the student gets a chance to fix and retry.