Moving an exam online replaces one threat model with another. The invigilator walking between desks is gone, and what replaces them is a piece of software running on a machine the candidate controls.
That framing matters, because it sets the ceiling on what is achievable.
What lockdown software does
Safe Exam Browser turns a normal computer into a kiosk for the duration of the exam. It takes over the display, blocks task switching, disables shortcuts, prevents screen capture, and refuses to run alongside processes on a deny list.
It also does the part that people forget: it proves to the server that it is the thing talking. A browser exam key, derived from the configuration and the exam URL, is sent with each request. The server checks it and rejects anything that does not match.
Configuration is the security boundary
The config file is where the actual policy lives — which URLs are reachable, whether a calculator is allowed, whether the session may be resumed, what happens when the network drops.
It should be signed and delivered by the institution, never assembled by the candidate. A configuration a student can edit is a configuration that permits whatever they want.
Plan for the network dropping
This is the requirement that separates systems that survive contact with real candidates from those that do not. Connections fail mid-exam. Laptops sleep. Power cuts happen — in some regions, reliably.
The design has to answer:
- Are answers saved locally and reconciled, or lost?
- Can a session be resumed on the same machine, and how is that authorised?
- Does the clock keep running while the candidate is disconnected?
Each of these is a policy decision before it is a technical one, and each needs an answer before the first exam, not during it.
The honest limit
Lockdown software secures the machine running the exam. It cannot see the second laptop, the phone under the desk, or the person in the room.
Recognising that boundary is what leads to sensible design: use lockdown to make casual cheating hard, and use assessment design — question banks, randomised ordering, time pressure, questions that reward understanding over recall — for everything beyond it.
A system sold as making cheating impossible will disappoint. One that raises the cost of cheating above the cost of preparing is doing its job.