Threat Modelling: Assets, Adversaries and Trust Boundaries · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Name it before you defend it

Computing · Networks & Security · ages 21-22
Name ______________________   Date ____________
  1. In the school example, which asset hurts most if lost?

    • A public club timetable
    • Pupil records
    • Canteen price sheets
  2. What must you name before choosing defences?

    • Assets, adversaries, crossings
    • Firewalls, filters, and scanners
    • Logins, passwords, and updates
  3. Every defence should answer one named threat.

    Circle one:   True   False

  4. Where do you mark a trust boundary?

    • Where data moves to a new folder
    • Where trust or control changes
    • Where data is copied in one account
  5. A message asks for your password on a copied page. Who is the adversary?

    • The school mail server
    • Phishers
    • A pupil who mistyped a password
  6. How do you rank two assets?

    • By cost of loss
    • By alphabetical name order
    • By file size, largest first
  7. Which defence answers phishers in the school example?

    • Reply with your password to confirm
    • Forward the mail to everyone you know
    • Check the sender, open the known app
  8. A pricey filter stops no named threat. What do you do?

    • Keep the filter and add more rules
    • Buy a larger filter of the same kind
    • Defend a crossing that needs it
LightMySky · lightmysky.comW1-mt_VRXTkrNFvx-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

Name it before you defend it W1-mt_VRXTkrNFvx-s1

  1. Pupil records · In the school example, pupil records cost far more than a public timetable or price sheets when lost.
  2. Assets, adversaries, crossings · The three names aim every later defence at a real risk.
  3. True · Matching keeps effort on real risks instead of vague worries.
  4. Where trust or control changes · A boundary is where trust or control changes, so protection sits there.
  5. Phishers · Fake pages harvesting logins are the phisher method.
  6. By cost of loss · Loss cost decides where protection effort lands first.
  7. Check the sender, open the known app · A sender check plus sign-in in the known app starves the fake page.
  8. Defend a crossing that needs it · Unmatched effort should move to a crossing with a real adversary.
Worksheet · LightMySky