A team from Purdue University has developed new technology that allow public cameras to send personalized messages to smartphones without invading privacy, using a real-time, end-to-end system.
The new system, dubbed PHADE (Private Human Addressing), uses motion patterns as the address code for communication, instead of having to first learn the destination’s IP or MAC address.
“Our technology enables public cameras to send customized messages to targets without any prior registration,” He Wang, an assistant professor in the Purdue Department of Computer Science, said in a statement. “Our system serves as a bridge to connect surveillance cameras and people and protects targets’ privacy.”
With mass shootings becoming a growing concern in public spaces, PHADE could be used as a security tool. According to Wang, surveillance cameras and security companies could also integrate the technology into their products directly.
“PHADE may also be used by government agencies to enhance public safety,” PhD student Siyuan Cao said in a statement. “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.”
PHADE could also be used at museums where visitors receive information about the artifacts or exhibits they are viewing or in shopping malls to provide consumers with digital product information or coupons.
How it works
Using PHADE, the smartphone locally makes its own decision as to whether or not to accept a message from a nearby security camera.
PHADE uses a server to receive video streams from cameras to track people. The camera then builds a packet by linking a message to the address code and broadcasts the packet. The mobile device, after receiving the packet of each of the targets, uses sensors to extract its owner’s behavior and follow the same transformation to derive a second address code.
If the second address code matches with the address code in the message the smartphone automatically delivers the message to its owner.
The researchers overlapped communication and computation to help make the system real-time, while optimizing the pedestrian tracking algorithm to speed up the tracking process.
To ease some privacy concerns over the new technology, the researchers put in safe guards that will protect user privacy. PHADE will keep the users’ personal sensing data within their smartphones and transform the raw features of the data to blur partial details.
Other methods to communicate with cell phones come with limitations. Bluetooth beacons are often difficult to adjust the range of transmission and do not capture contextual information that security cameras can. Using RFID tags require user registration and is not suitable for public areas where not everyone might wear the tags.