How Wi-Fi technology helps people see into your home
Just days before a tens of thousands of computers in homes, business and government were infiltrated by malicious software, scientists warned Wi-Fi routers, the kind found in most Australian homes, present a major security risk.
Scientists for the first time produced a hologram using a wi-fi transmitter – instead of using a laser – furthering the growing research into wi-fi being used to spy through walls.
Holograms, of the sort made famous by Princess Leia in Star Wars are usually made by lasers, which produce what’s known as ‘coherent light’ in the form of beams.
German physicists from the Technische Universität München recognised that systems such as Wi-Fi or Bluetooth emit coherent light in the form of radio waves or electromagnetic radiation.
People could be able to peer into your home using wi-fi technology.
Which means that the radio waves coming out of every commercial Wi-Fi router – sitting on a kitchen bench or loungeroom cabinet – are constantly making a hologram of all the objects in the room the router occupies.
Dr Friedemann Reinhardat, an expert in quantum sensors, and Philipp M. Holl, an undergraduate student, proved the theory by recording the shape of a metre-wide aluminium cross by using two receivers that scanned for the radio waves.
The process involved using a version of synthetic aperture radar – the same technique used to make 3D images of mountain ranges on earth from spacecraft.
By running the recorded radiation backwards in time, in a computer, a 3D reconstruction of the cross came into being on the computer screen.
Wi-fi breakthrough
Science magazine, which reported the breakthrough early last week, noted that, “in principle, the technique could enable outsiders to ‘see’ the inside of a room using only the Wi-Fi signals leaking out of it, although some researchers say such spying may be easier said than done”.