Veovo offers the BlipTrack system, which detects mobile devices, such as smartphones that have an activated Bluetooth or Wi-Fi radio. By mounting sensors in several locations and tracking the devices, specific and accurate statistical information, such as movement times and movement patterns, can be collected and analysed.
If Bluetooth or Wi-Fi in a mobile device is activated, the device frequently broadcasts its Bluetooth or Wi-Fi MAC address. A MAC address a unique identifier used by the Bluetooth and Wi-Fi technology to enable communication between Bluetooth or Wi-Fi devices.
When a device with an activated Bluetooth or Wi-Fi radio passes a BlipTrack sensor, the device’s Bluetooth or Wi-Fi MAC address (6 bytes long) is captured. This information is not stored by the sensor but is immediately processed by a cryptographic hash algorithm (SHA256), which generates a 32-bytes hash value. Hashing is done using an 8-bytes salt1. The same salt is used by all the sensors within the system and a given MAC address processed by any sensor will always result in the same hash value.
This hash value is transferred securely to the BlipTrack server, where the received value is hashed again using a different 8-bytes salt. This salt is randomly generated every 24 hours and only stored in temporary server memory. No logs of previously used salts are kept.
The resulting hash value – consisting of 32 bytes – is truncated by the server to 8 bytes, after which the information is analysed.
Along with the final hash value, information on the location of the sensor, which captured the Bluetooth or Wi-Fi radio, and the strength of the signal is also processed along with a timestamp of when the Bluetooth or Wi-Fi MAC address was captured by the sensor.
Based on these data, it is possible to establish a link between devices and analyse movement times and movement patterns. The system can inter alia be used to perform the following analyses:
- Time elapsed from a device being captured by one sensor to another sensor, which can be used to calculate the movement time between endpoints.
- Duration of time where a device stays within reach of one sensor, which allows for the analyses of movement flow.
- Identification of a device within the system to ascertain the taken route e.g., if the movement has occurred via certain points.
1. A salt is a random value added to the attribute being hashed.