The protections are account-level, and this answer names them rather than gesturing at a standard. Nothing on this platform runs without an account, on the free demo as much as on Premium; only one session on that account can be active at a time, passwords are held to complexity rules, the registration and sign-in forms both carry a challenge, and repeated failed sign-ins are throttled.
Security answers are usually written to reassure and are difficult to check afterwards. This one is written to be checked: every control above is something you will meet yourself on the way in, the first time you register and every time you sign in after that.
What Your NWExam Account Actually Holds
The list is a short one. Signing up collects a username, an email address and a password, together with the exam code you name as the one you are working towards — picked from the site’s list of networking and infrastructure tracks, and a statement of intent rather than a purchase — plus acceptance of the terms. What builds up after that is your practice: the sittings you have completed, what you scored on them, and the item-by-item record behind each one. The only thing the account can do with that record is read it, which is why nothing in your settings clears it, and the answer on resetting results sets out what follows from that. Nor does the record accumulate for ever: each attempt is removed automatically once its retention period ends, with nobody choosing which one goes.
What Guards the Sign-In to a Practice Exam Account
Four things, and you can confirm every one of them yourself on the way in.