CCTV could send passers-by personalised messages by watching their gait
Image credit: He Wang
Researchers based at Purdue University have developed a system which allows public cameras to deliver secure, personalised messages to people in view of their lenses.
This is a process known as ‘private human addressing’. Previously, attempts to deliver personal messages to passers-by – essentially the digital version of note passing – were complicated by the impossibility of sending a message without knowing some details of their device, such as their IP address or MAC address.
However, the system - known as Phade - developed at Purdue works around this problem by picking up the patterns of a person’s motion from public cameras and using this as identifying information for communication.
Phade receives real-time video streams from public cameras, in which it can track individuals. The system then builds a ‘packet’ by creating a personalised message, linking it to the target’s ‘address code’ and broadcasting it. When nearby devices receive this packet, they use their own sensors to generate its address code. If the device belongs to the intended recipient, the address codes will match and the message will be shown to the device’s user.
This system’s context-aware messaging capabilities set it aside from Bluetooth-based beacons.
“Our technology enables public cameras to send customised messages to targets without any prior registration,” said Professor He Wang, the Purdue University computer scientist who led development of the Phade system. “Our system serves as a bridge to connect surveillance cameras and people and protects targets’ privacy.”
While rolling out the system in the real world could spark Orwellian fears of being followed and identifiable wherever you go, the team behind Phade say that they have kept privacy in mind while designing it. The system keeps personal sensing data without their own devices and this data is blurred in order to remove identifiable details (this fading process led to the system being christened Phade).
The researchers suggest that it could be used in enclosed spaces such as museums and galleries, where visitors can be sent messages containing extra messages about the exhibits they are viewing; in shopping centres, to offer discount coupons and product information, or in future cashier-free shops similar to the experimental Amazon Go shop.
Alternatively, the system could be used to deliver safety messages to passers-by. While permanent threats can be labelled clearly with low-tech signs, Phade could be used to alert the public to fleeting threats.
“Phade may also be used by government agencies to enhance public safety,” said Siyuan Cao, a PhD student who helped develop Phade. “For example, the government can deploy cameras in high crime or high accident areas and warn specific users about potential threats, such as suspicious followers.”