Author Thread- Follow Up

A phone number can reveal whether a device is active, in standby or offline (and more). This PoC demonstrates how delivery receipts + RTT timing leak sensitive device-activity patterns. (WhatsApp / Signal)

What it does: By measuring Round-Trip Time (RTT) of WhatsApp message delivery receipts, this tool can detect:

  • When a user is actively using their device (low RTT)
  • When the device is in standby/idle mode (higher RTT)
  • Potential location changes (mobile data vs. WiFi)
  • Activity patterns over time