A warehouse wireless passphrase was posted on the break-room wall, and the contractor who knew that passphrase has left the job. Which action is proper key management?
Select an answer to reveal the explanation.
Short Explanation
A door code that was taped to the glass, and that a former contractor still remembers, is a code you have to change. You rotate the passphrase and hand the new one to current staff through a channel you control. Keeping the old secret behind a hardware-address list, taping the new code to the same wall, or renaming the network and leaving the passphrase does not retire it.
Full Explanation
Key management covers how a secret is rotated and distributed. The passphrase was posted on the wall, and a contractor who knew it has left. Rotating it and giving the new value only to current staff through a controlled channel retires the exposed secret. MAC filtering leaves the posted passphrase in place. The contractor who still knows it can present an allowed address. Posting the replacement on the same wall repeats the disclosure, so the rotation never limited who knows it. Changing the wireless name is the tempting twin because the old network looks gone. Anyone who still knows the passphrase joins the new name. Exam caveat: rotation has to reach every access point, or a point that still holds the old value accepts the contractor. Operational check: confirm the old passphrase is rejected, confirm a current staff device connects with the new one, and confirm the wall no longer shows a passphrase. Record the reading before the change and the reading after it so the next shift can see the symptom actually moved.