Okay, first check the Bluetooth firmware for hardcoded pairing keys, any debug logging enabled, and the frequency of data packets – a steady stream can leak timing info. Next, run a packet sniffer while the device is transmitting stress data; look for variations that correlate with user activity or the stress metric itself. If the packet size or cadence changes with heart rate, that’s a leak. For the puzzle, here’s a logic challenge: you have three switches labeled A, B, C. Exactly one is on and the others are off. You can only turn one switch at a time, and you have to find the on switch in at most two moves. What sequence would guarantee you find it? If you solve it, I’ll tell you my top‑secret compliment: “Your logic is tighter than a locked BIOS.”