During World War II, British intelligence officials have tapped the German radio. English noted that the Germans have their own rhythm generation timekeeping features, Allied spies soon will know that the style of each member of the German transmitters.
They managed to track the activities of members of the German transmitter, which is equivalent to members of their units to track the activities of transmitters.
Today, the Internet as an electronic means of communication, has basically replaced the telegraph. However, when people use the Internet still retains the characteristics of each style. At present, the scientists concluded that "typing fingerprint", "click fingerprint" and "Writing fingerprint" of these three "digital fingerprint."
"Typing fingerprint" from the start tapping the keyboard
In 1980, the United States, RAND researchers find ways to improve computer login password security methods. After World War II inspired the story of British intelligence officers, they think of an idea: Perhaps, like telegraph transmitters typist members, can be identified under the typing rhythm.
Now researchers are developing the technology in applications other than password authentication. University of Turin, Italy 涓瑰凹灏斿彜鍐呰拏 and 鍏嬪姵杩▍鐨?Cady development of a test typing rhythm system that not only computer time for landing. Piccadilly, said: "We use it to track a special interest in the network of illegal activities."
First of all, the system scans a person's normal process of typing, and understand all the different typing rhythm, not only when the input password. System will then continuously monitor the rhythm.
If hackers want to get into someone else's computer account, "typing fingerprint" of the system will notice a different type type, then the alarm. In 2005, Italian researchers reported that 200 of the system in each type produced during the about 1 false alarm.
"Typing fingerprint" can be used to identify the Web site, asking them to enter a certain amount of text. Picardie said that internet e-mail service providers such as Gmail and Yahoo all want to use this technology to protect e-mail account. Piccadilly also noted the on-line forum. "Typing fingerprint" program to identify illegal activities of people posting.
Analysis of "typing fingerprint" caused a lot of privacy concerns. Piccadilly, the police can collect a lot of people typing habits, and then from the public computers they identified. Even without knowing the type used under the conditions of the people, the police or from the public computer on-line forum to get their rhythm by typing the information. Such as the police can know a person's native language, because the most commonly used rapid typing keystroke combination will vary with the mother tongue.
Gunetti and procedures Piccadilly will not record the contents of people typing and keystroke sequence, only two keystrokes for each record the average time between. However, if the contents of small type, it may be sufficient to allow others to guess the contents of the article.
Move the mouse form "Click fingerprint"
The keyboard is not the only means of computer input. The rise of the network, the computer mouse has become an increasingly important input means.
Piccadilly and Gunetti are testing the computer system according to an intruder mouse was found the method. They suspect that people usually when moving the mouse, the shape and speed can be identified.
From the University of London's Bidemaike Owen said that the movement of the mouse can be used to sign. When the test participants draw their own signature with the mouse, he was in the side of the record. Participant in the experiment can be drawn with the mouse pen and paper to write their normal signature, or they choose their own graphics. Michael Owen with the digital signature as a password for additional means to strengthen the authentication of computer users.
In order to test the effectiveness of this approach, Mike Owen, the third person to test participants password. He also painted with the mouse first third of the way the password record. After combination of passwords and digital signatures, 95% of the participants in the experiment were rejected as an intruder when the landing computer, while more than 99% of study participants as a computer owner to login.
"Click stream" of online habits
Other researchers study people click of the mouse and scroll the mouse when browsing the web way. Two U.S. researchers proposed a "clickstream data" concept. The so-called click-stream data, that is, when people click on anything. They are now looking for ways to apply this concept, hope can be used to verify the identity of website users and prevent online fraud.
Suppose a person would normally only in the Saturday afternoon, a visit to an online bookstore, spend 15 minutes or so visit the website, read the comments of gardening books, but always only a registered credit card to buy a book. In a Monday morning, it was claimed to be the person in front, at 8 minutes later to buy five science fiction, online bookstore may have to suspect this is fraud. Bookstore visitors can request additional authentication, such as Xiangna personal e-mail address to send a letter.
Authentication point is collected from various people's behavior data. Researchers present in the experimental procedure, the only difference between the length of recording time, time, day of the week and web page views and other data. They found that the site "click stream data" program requires at least 30 aspects of the data to identify a particular user's habits. Even then, the program's accuracy rate is only 80% or so. And if the views of a larger site, users need to analyze the habits more.
The researchers also said that if people want to be "click fingerprint" identified, they can easily change their habits to avoid detection. On the other hand, if the bad guys want to successfully imitate you, not so easy. "They had exactly like you want to imitate the people do to change their behavior," one researcher said.
Online posts will remain, "write fingerprint"
As early as 1804, when scientists have used statistical analysis of people's writing style. Scientists already knew at that time more than one thousand kinds of characteristics of the writing style.
University of Arizona researcher Chen Qingchun information systems (transliteration) recently thought of the writing style of this analysis can be applied to a different question above. He said: "This technology can track any network would like to hide their identities. They will leave marks."
Internet users are generally inside the anonymous online forum post, or use a different user name. Chen Qingchun of law enforcement agencies can detect the different posts is not the same person released.
Chenqing Chun and his colleagues have studied from the United States the "three K Party", the Palestinian militant group Al Aqsa Martyrs Brigades and the online sale of pirated software and music news forum.
The researchers considered the habit of writing news publishers, including the choice of words, punctuation, use of passive frequency, capital letters and lowercase letters of the ratio, the article length, and each piece of text in the box before the first line. Chen Qingchun research team also analyzed the content of the article, such as the article did not express hatred in the statement, or such as "sale" of the phrase.
Comparison and analysis of the written articles, online news different researchers have encountered some difficulties. Online news tend to be shorter, more casual, so spelling errors and punctuation mistakes more. And in online forums to post hundreds or more people, carved from clear who each posted is not easy.
On the other hand, the Web forums where users can post a variety of fonts, colors, links, and different ways to invoke other users posts, these can be provided to the researchers study the characteristics of the written article which is rare.
鈻?Links
"Writing fingerprint" the highest accuracy
Chen Qingchun and colleagues identified 270 English usage characteristics, and then use computer programs to single out the 134 Internet users from posting the most different characteristics, then the 134 characteristics of online forum posts. They also studied Chinese and Arabic posts.
The researchers made a final drawing, which they call "writing fingerprint." It can display each person writing a post feature. Computer program to every post into each containing 50 or 60 words of the section, a separate analysis of each section, and then sum up the best style of all aspects of that post.
Researchers reported last year that had a certain post in the analysis of the 30 to 40 posts later, no matter who he is, the computer program can accurately identify the post that he later released. Computer program on the accuracy of the Chinese post is 93%, the Arabic language posts to 95% standard rate, while the English posts on the accuracy rate of 99%.
