Batu69 Posted August 25, 2016 Share Posted August 25, 2016 It can even be trained to read your lips. City dwellers spend nearly every moment of every day awash in wi-fi signals. Homes, streets, businesses, and office buildings are constantly blasting wireless signals every which way for the benefit of nearby phones, tablets, laptops, wearables, and other connected paraphernalia. When those devices connect to a router, they send requests for information—a weather forecast, the latest sports scores, a news article—and, in turn, receive that data, all over the air. As it communicates with the devices, the router is also gathering information about how its signals are traveling through the air, and whether they’re being disrupted by obstacles or interference. With that data, the router can make small adjustments to communicate more reliably with the devices it’s connected to. But it can also be used to monitor humans—and in surprisingly detailed ways. As people move through a space with a wi-fi signal, their bodies affect it, absorbing some waves and reflecting others in various directions. By analyzing the exact ways that a wi-fi signal is altered when a human moves through it, researchers can “see” what someone writes with their finger in the air, identify a particular person by the way that they walk, and even read a person’s lips with startling accuracy—in some cases even if a router isn’t in the same room as the person performing the actions. Several recent experiments have focused on using wi-fi signals to identify people, either based on their body shape or the specific way they tend to move. Earlier this month, a group of computer-science researchers at Northwestern Polytechnical University in China posted a paper to an online archive of scientific research, detailing a system that can accurately identify humans as they walk through a door nine times out of ten. The system must first be trained: It has to learn individuals’ body shapes so that it can identify them later. After memorizing body shapes, the system, which the researchers named FreeSense, watches for people walking across its line of sight. If it’s told that the next passerby will be one of two people, the system can correctly identify which it is 95 percent of the time. If it’s choosing between six people, it identifies the right one 89 percent of the time. The researchers proposed using their technology in a smart-home setting: If the router senses one person’s entry into a room, it could communicate with other connected devices—lights, appliances, window shades—to customize the room to that person’s preferences. FreeSense mirrored another wi-fi-based identification system that a group of researchers from Australia and the UK presented at a conference earlier this year. Their system, Wi-Fi ID, focused on gait as a way to identify people from among a small group. It achieved 93 percent accuracy when choosing among two people, and 77 percent when choosing from among six. Eventually, the researchers wrote, the system could become accurate enough that it could sound an alarm if an unrecognized intruder entered. Something in the way? No problem. A pair of MIT researchers wrote in 2013 that they could use a router to detect the number of humans in a room and identify some basic arm gestures, even through a wall. They could tell how many people were in a room from behind a solid wooden door, a 6-inch hollow wall supported by steel beams, or an 8-inch concrete wall—and detect messages drawn in the air from a distance of five meters (but still in another room) with 100 percent accuracy. (Using more precise sensors, the same MIT researchers went on to develop systems that can distinguish between different people standing behind walls, and remotely monitor breathing and heart rates with 99 percent accuracy. President Obama got a glimpse of the latter technology during last year’s White House Demo Day in the form of Emerald, a device geared towards elderly people that can detect physical activity and falls throughout an entire home. The device even tries to predict falls before they happen by monitoring a person’s movement patterns.) Beyond human identification and general gesture recognition, wi-fi signals can be used to discern even the slightest of movements with extreme precision. A system called “WiKey” presented at a conference last year could tell what keys a user was pressing on a keyboard by monitoring minute finger movements. Once trained, WiKey could recognize a sentence as it was typed with 93.5 percent accuracy—all using nothing but a commercially available router and some custom code created by the researchers. And a group of researchers led by a Berkeley Ph.D. student presented technology at a 2014 conference that could “hear” what people were saying by analyzing the distortions and reflections in wi-fi signals created by their moving mouths. The system could determine which words from a list of lip-readable vocabulary were being said with 91 percent accuracy when one person was speaking, and 74 percent accuracy when three people were speaking at the same time. Many researchers presented their wi-fi sensing technology as a way to preserve privacy while still capturing important data. Instead of using cameras to monitor a space—recording and preserving everything that happens in detail—a router-based system could detect movements or actions without intruding too much, they said. I asked the lead researcher behind WiKey, Kamran Ali, whether his technology could be used to secretly steal sensitive data. Ali said the system only works in controlled environments, and with rigorous training. “So, it is not a big privacy concern for now, no worries there,” wrote Ali, a Ph.D. student at Michigan State University, in an email. But as wi-fi “vision” evolves, it may become more adaptable and need less training. And if a hacker is able to gain access to a router and install a WiKey-like software package—or trick a user into connecting to a malicious router—he or she can try to eavesdrop on what’s being typed nearby without the user ever knowing. Since all of these ideas piggyback on one of the most ubiquitous wireless signals, they’re ripe for wide distribution once they’re refined, without the need for any new or expensive equipment. Routers could soon keep kids and older adults safe, log daily activities, or make a smart home run more smoothly—but, if invaded by a malicious hacker, they could also be turned into incredibly sophisticated hubs for monitoring and surveillance. 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Petrovic Posted August 29, 2016 Share Posted August 29, 2016 Researchers have devised a system that can recognize a user's keystrokes by exploiting available WiFi signals. The research team, which is made up of computer scientists from Michigan State University and Nanjing University in China, explain in their paper (PDF) that their "WiKey" system works because most WiFi devices (including routers) come with multiple-input and multiple-output (MIMO) capabilities: Quote "Each MIMO channel between each transmit-receive (TX-RX) antenna pair of a transmitter and receiver comprises of multiple sub-carriers. These WiFi devices continuously monitor the state of the wireless channel to effectively perform transmit power allocations and rate adaptations for each individual MIMOstream such that the available capacity of the wireless channel is maximally utilized...." In other words, most routers have the ability to monitor a wireless channel's behavior and pick up on its channel state information (CSI). Those CSI values, in turn, characterize something that's known as Channel Frequency Response (CFR), or fluctuations in signal exhibited between each antenna pair for a subcarrier. Those fluctuations reveal a lot about a WiFi channel. As it turns out, they can even reveal hand and finger movements--that is, a user's keystrokes. In their experiment, the researchers used a TP-Link TL-WR1043ND WiFi router and a Lenovo X200 laptop. While a subject typed on the laptop, the researcher used the router's antennas to pick up all existing CSI values. They then passed that data through several different types of filtering to eliminate other sources of noise and to isolate the keystrokes. Using a specially designed algorithm, the researchers were able to identify that each keystroke had a start- and endpoint and that it rose and fell like a wave. This information proved instrumental in extracting the actual keystrokes themselves. Overall, WiKey registered a 96.4 percent success rate in classifying single keystrokes. That accuracy fell slightly to 93.5 percent when researchers adjusted the experiment so that the subject typed keys in a continuous sentence. Computer criminals and researchers have looking at keyboard security for years now. Through their combined efforts, they've not only demonstrated that malware can intercept keystrokes in the form of FM radio signals from an isolated computer; they've also proven that a user can be identified and tracked based upon how they type. Clearly, WiKey builds upon that existing body of research. That's not to say the system is without limitations. For the experiment, researchers set a number of controls, such as an environment with very little noise, a close device proximity of two meters between the router and the keyboard, and training requirements that spanned only over the course of one day and which required the subjects to not move their heads or other parts of their body. In the real world, everything is a lot more dynamic. The researchers know that, and they're hoping to improve on their system so that it accounts for such factors: Quote "...n future we plan to address the problem of mitigating the effects of more harsh wireless en-vironments by building on our micro-gesture extraction and recognition techniques proposed in this paper." For more information about WiKey, check out the researchers' paper here. Article source Link to comment Share on other sites More sharing options...
knowledge-Spammer Posted August 29, 2016 Share Posted August 29, 2016 are able Link to comment Share on other sites More sharing options...
straycat19 Posted August 29, 2016 Share Posted August 29, 2016 This is nothing new. Wireless keyboards are also very susceptible to having their keystrokes intercepted. I believe the first reported incident of wirelessly intercepting key strokes was in the late 90s. By the early 2000s it was doctrine that wireless keyboards not be used on systems with classified or personal and financial information on them if there was a possibility of a wireless intercept device being introduced into the area. The key to this is you have to have a device close enough to capture the signal from a specific system. If you try it in a large room with many computers you end up with gibberish. Link to comment Share on other sites More sharing options...
Batu69 Posted August 30, 2016 Author Share Posted August 30, 2016 Thread has been merged. Link to comment Share on other sites More sharing options...
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