Now we, all the time in the use of wireless devices, mobile phones, laptops and so on wireless network equipment, the router has become a part of our daily life can not be missing. But you may not understand, even if not the wireless signal carries data itself to decrypt, the wireless signal can also reveal our privacy, the attacker can even use it to steal passwords, the whole process sounds very black technology.
Multi function wireless signal
Router is the most common in our daily life, the Internet through the router to connect to the network, and then browse the sports news, weather information, wireless router sends the signal transmitted in the air, of course, in the transmission process will encounter obstacles, and then according to whether the signal router was obstructions and airborne signals, there are these data, it can acquire signals in the air in the propagation path, will not be hindered or interference. With this information, you can make the router network more stable self adjustment.
andIt can also be used to monitor human activities, when a person is full of mobile WiFi in the signal space, between the signal and the human body contact and change, even through the other direction of reflection to other people, such a phenomenon based on, researchers can use it to complete the positioning of a person you can see, what one finger to write in the air, a person walking pace, and even a person in the room of the lips peristalsis.
WIFI band in the world is no need for any telecommunications operator license free bandThe WLAN wireless device provides a wireless air interface with high cost and high data bandwidth, which can be used in the world. Second, the investment cost is very low, the installation is very convenient to use, without the need for professionals to build the network, which makes it more popular. The disadvantage is the transmission distance, can only close indoor signal transmission, the diffraction ability is very poor, the signal transmission as much as possible to avoid obstacles.
But WIFI is indeed we are very familiar with the daily use of wireless network signals, so it is convenient to use more of the.Recently, some experiments have been carried out based on the WiFi signal, which is mainly used to identify the body state of the human body and the way of walking in the WiFi signal.
Recently, Northwestern Polytechnical University announced its own research technology FreeSense, the system needs to learn". This technology can be used to understand the situation of the human body, and then can be identified and memory of the human state. That is to say that this technology can use WiFi signal to achieve the identification of different human body information, the main use of different human body for the WiFi signal absorption and reflection of differences, to judge the individual behavior information. Tests show that when the system is selected between two people, the correct rate can reach 95%. When the choice between 6 people, the system is able to achieve the correct rate of 89%. This technology first need to know the size of a person in advance, then it will be able to recognize the individual by observing the reflection mode of the wireless signal.
So the researchers say the technology could be used in smart homes. When the router detects a person into the room, it can be based on the situation of the curtain, lights and other equipment to regulate and control. Can therefore be used for anti-theft system, once the device has not been recorded in the human body information, will be issued to the police, or the alarm message sent to the owner's mobile phone and other terminal.
FreeSense from the other with a Wi-Fi signal based identification system, this system is called Wi-Fi ID, in an earlier group from Australia and British researchers said in a meeting to put forward a new system, and the main analysis of this system, in order to determine the entire target groups. The target to two cases, the accuracy was 93%, when reached 6 cases, the accuracy was 77%, the researchers said in a report, when an intruder exposed in the system, the system can accurately alarm.
In 2013, researchers at the Massachusetts Institute of technology and the University of science and technology said in a report:
They can be judged by the router in a room how many people, and can determine the position of the arms of the room side, can even partition to determine the room number. This room in the experiment is mainly supported by a steel beam 6 inches of hollow walls or a 8 inch concrete wall structures, the whole experiment is carried out in the wall 5 meters. Using the router can detect the air in the message, the accuracy rate of up to 100%.
Then Massachusetts Institute of Technology (MIT), a computer science and Artificial Intelligence Lab, has released a technology that looks at some "black technology" in general.WiFi to know the name of someone else this set of RF- capture device, through the analysis of the reflection signal, you can put together a person's shape.This technology can be used to detect objects running on the other side of the wall or obstacles. RF- capture device can be distinguished from the other side of the wall body and human body subtle differences, the accuracy rate reached 90%.
According to the researchers,This technique can distinguish the difference between 15 different people, and even can monitor a person's respiratory rate and heart rate.. If this technology and equipment have been applied and universal, they can be used to track the daily activities of elderly people living alone, to understand their heartbeat, breathing and other vital signs are normal, whether there is a fall, etc.. It is worth noting that last year President Obama at the White House (Demo Day) on the demonstration appeared in this technology, it is a device designed for the elderly, called Emerald, it can detect the physical activities and the fallen, even through the action mode of observing people predict the fall.
Safety makes people worry
In addition to identifying people and vague gestures, Wi-Fi signals can also be used to accurately identify the most subtle movements. Earlier researchers at Michigan State University and the Nanjing University found that using the WiFi signal from the plane routing can accurately obtain the key information. It can tell the user to enter the password on the keyboard by monitoring the subtle finger movements. A previous hacker Conference on someone to demonstrate this system called "Wikey". Once trained, Wikey can recognize human input sentence, the accuracy rate of 93.5%, and this all just need a common market router and a set of code.
As previously described Wi-Fi signal was used to read gestures and lip movements, so the accuracy of the Wi-Fi signal has been established. In the WiKey test, the researchers used the existing devices, such as TL-WR1043ND Wi-Fi TP-Link routing and a Lenovo X200 notebook. The researchers scanned the room with a number of WiFi signals, mapping out the map out of the room.
WiKey only applies to rooms that have little or no human activity. In the front of the notebook, the start typing, the user's hand and finger as well as the keyboard of the micro switch can affect the transmission of Wi-Fi signals, WiKey will be able to capture this change. The researchers said, through the training of a special kind of computer algorithms, tap their project can be judged every keystroke which key is specific, finally can reproduce the text input user notebook. In real situations, the accuracy of the system is between 77.43% (30 sample data) and 93.47% (80 sample data) due to the interference of the Wi-Fi signal field and the excessive typing. Although there are limitations in terms of accuracy, but malicious attackers use this technology can know your password 3\/4.
A student led by Dr. Berkeley in 2014, the team had "lip reading literacy", which causes the Wi-Fi signal through the analysis of lip movement interference and reflection to learn what someone said, this system from a series of lip readable words with 91% accuracy to analyze a person is saying at the same time, there are three people in words, speak with 74% accuracy. Security researchers believe that the surveillance camera will record to save people and the router system is obviously every act and every move, to explore in the premise of not infringing privacy too much under the action of people and activities.
The reporter has interviewed Wikey's chief researcher Ali Kamran, and asked whether his technology will steal sensitive data, Ali said the system through rigorous testing and training, only in controlled environments. "So there's no need to worry about privacy so far." Ali wrote in an e-mail that he was a doctoral student at the Michigan State University.
In the process of development of such technology, many security researchers proposed this technique as a way to protect the security of user data, but there are still many people worry that, in view of these techniques are the most common in the establishment of wireless signal in life, do not rely on any new or expensive equipment, so it is easy to get started.Once the malicious attacker to get a similar WiKey approach and the production of malicious software, and then induce the user to install, and finally led to the user's privacy leak, causing network security issues. With the development of technology,This technology can be developed for the text, as the elderly or children's monitoring device, but also can record the daily activities or to help the intelligent operation of home equipment. But this way will encounter malicious attackers into malicious software and the monitoring is likely to become the privacy of Damour Damocles, there may even become a means of making money, have to worry about the safety of this cause.
