Which Bluetooth security mode is non-secure?

• A. Security mode 1
• B. Security mode 2
• C. Security mode 3
• D. Security mode 4

Answer: (A)

Bluetooth security modes determine when authentication and encryption occur during a connection. In the non-secure option, there is no pairing, no authentication, and no encryption—the link can be established and data sent without any security checks. That means anyone within range could connect and potentially eavesdrop on traffic or impersonate a device, so this mode provides no protection and is generally avoided unless compatibility forces it. Other modes add security at different points: one mode enforces security per service after a service policy is applied; another mode requires authentication and encryption at the link level during connection; the final mode uses Secure Simple Pairing to streamline and strengthen the pairing process. The key takeaway is that non-secure mode offers no protection, making it the choice that corresponds to a lack of security.