A new wireless technology in development by MIT’s Computer Science and Artificial Intelligence Lab could allow us to finally say goodbye to the Wi-Fi password.
The technology, currently named Chronos, is capable of allowing a single wireless access point to detect the location of networked users to tens of centimetres in accuracy. This immediately has a number of possible applications, one of which could allow wi-fi networks to be limited in access to only those within the building, as well as smart home applications such as tracking people’s movement and adjusting temperature and lighting as they move.
Chronos works by computing the “time of flight” of a wireless signal with an average error of just 0.47 nanoseconds according to MIT, which when multiplied by the speed of light allows Chronos to accurately detect not only the angle from the access point a user is at, but also their distance from it. Comparatively, existing wi-fi devices lack the bandwidth to accurately measure the time of flight of a signal, so in order to detect the locations of users, multiple access points were required for triangulation.
It was discovered after MIT Ph.D. student Deepak Vasisht observed that the signals travel through the air at a different frequency than within a Wi-Fi device that is being detected. He and his team were then able to exploit this difference in signals, testing their new algorithm in a two-bedroom apartment containing four people, where Chronos could accurately detect the room a user was in 94% of the time. When tested in a cafe, the detection rate of in-store customers compared to out-of-store hijackers was 97% accurate, which could allow wireless passwords to be rendered redundant in such cases, as only those in the store can connect to the network.
Whether this will truly be the end of the wireless password is unlikely, as there will always be a call for a higher level of security on many networks. For lightly restricted public networks, though, this technology could be a godsend, without requiring businesses set up a complex multi-access-point solution. A paper summarizing the study of the technology was presented last month by Vasisht at the USENIX Symposium on Networked Systems Design and Implementation.