DE202013100910U1 - CAPTCHA for distinguishing computers and people in the interaction of computers - Google Patents

Abstract

CAPTCHA distinguishes between computers and people interacting with computers to prevent unwanted effects of an external computer using automated access programs, especially those known as spybots or spam servers, through a fully automatic Turing test to distinguish computers and humans, generally CAPTCHA designated, characterized in that a graphic, which consists of a sequence of numbers, letters and / or characters and forms an access code in its sequence is arranged on a surface having a predetermined length and height, and that in a continuous text whose line length the Number of pixels of the width of the graphic and its number of lines corresponds to the number of pixels of the height of the graphic, the individual characters of the continuous text is assigned a color by means of a formatting tag which corresponds to the color of the respective pixel of the graphic and which can be activated only when the continuous text is marked i st, that the body text is attached as an HTML file to the file to be backed up and sent to the recipient machine so that it opens in a separate window when activating the file to be backed up, that the entire body text can be marked by manual operations, each letter of the body text and / or the background is assigned the color contained in the tag so that the access code becomes visible on the window surface and this can be entered into the file to be saved.

Description

The invention describes a CAPTCHA for distinguishing computers and humans in the interaction of computers.

It is designed to prevent unwanted external computer interference by using automated access programs, especially those known as spybot or spam servers.

Internet sites, especially those that can be caused by visitors to the website to any reactions, are today exposed to a variety of attacks that go from the spying of addresses to the elimination of a server through automated queries on so-called bots.

For this reason, one tries to prevent the access of machines on such Internet sites. Probates means for this are so-called CAPTCHA, which release the Internet page only for the reaction, if a positive answer exists.

A CAPTCHA ("Completely Automated Public Turing Test Tell Me Computer and Humans Apart") is a type of question-answering test that is used to provide assurance to ensure that the answer is not generated by a computer. It asks the user of a website to complete a test that the computer can generate and evaluate.

In the simplest case, the visitor to the website is provided with a mathematical task in which the factors are generated by a random generator. The correct solution of the task then serves as an access code.

Well-known is a movie hoster service, where the ball constantly rolls over the captcha. However, there is a risk that the ball is perceived as a dash, which is why the captcha appears crossed out and is insoluble.

Other CAPTCHA rely on distorting a string and / or placing it under a network of lines so that simple OCR programs can not recognize them.

Since computers are usually unable to resolve the CAPTCHA, it is assumed that every user who enters a correct solution is a human.

Such CAPTCHA have also been patented or patented in the past.

So will in the DE 10 2011 012 471 A1 a method for protecting against automated access of at least one first computer unit to at least one protected resource of a second computer unit is presented, in which the second computer unit is connected to the first computer unit via a data communication connection.

The present invention is characterized in particular in that on a display unit of the first computer unit a phrase consisting of words and / or symbols with a phrasonic content and at least one symbol selection area with a plurality of graphical symbols is displayed that at least partially graphical symbols are displayed, which human user associates a symbol sense content. Access to the protected resource of the second computer unit takes place only after correct reproduction of the phrase content by selecting graphic symbols from the symbol selection area with corresponding symbol meaning content.

Another method for identifying whether a web client has browser capabilities is in the DE 11 2010 002 445 T5 demonstrated. In this method, an originator receives a Web page call from the Web client.

The originator generates a page invocation ID (PRID) and a script that, when executed by a web client with a browser, regenerates a PRID and embeds the script in a response. The originator sends the response back to the web client so that it processes the web client, and if the web client is able to execute the embedded script, it regenerates a PRID and returns the regenerated PRID to the originator. The originator compares the returned regenerated PRID with the generated PRID, with a match indicating that the web client has browser capabilities.

In the US 6,195,698 B1 there is presented a computerized method for accepting an access request from a client computer on a server computer in a network that operates as follows.

The server computer receives an access request from the client computer. In response, the server computer generates a predetermined number of random characters. The random characters are used to form a string in the server computer. The string is randomly changed to a puzzle either visually or acoustically. The original string will be the correct answer to the puzzle. The server computer sends the puzzle to an output device of the client computer. In response, the client computer sends a response to the server.

The server checks if the answer is correct. If the answer is positive, the access request is accepted. If the correct response is not received within a predetermined amount of time, the connection between the client and server computers is terminated by the server on the assumption that the client is an automaton.

A disadvantage of the CAPTCHA known hitherto that, in order to prevent automated spying, these are often barely solvable even for people who have limited eyesight.

The object of the invention is therefore to propose a CAPTCHA for the distinction of computers and people in the interaction of computers, which offers good protection despite good legibility of the code string.

The problem is solved by a CAPTCHA designed according to the features of the main claim.

In the subclaims further improvements are proposed for this purpose.

As already known from other similar methods, a graphic is the basis that consists of a sequence of numbers, letters, and / or characters that form an access code in their sequence. These numbers, letters and / or characters are arranged on a surface of a given length and height.

In a continuous text whose line length corresponds to the number of pixels of the width of the graphic and whose number of lines corresponds to the number of pixels of the height of the graphic, a color corresponding to the color of the respective pixel of the graphic is assigned to each individual character of the continuous text by means of a formatting tag Formatting is done so that it is activated only when marking the body text.

The modified source code can be sent directly to the recipient computer as a separate HTML file as soon as it confirms the opening of a new window with a click. The access code can be queried in an input field, usually when sending a form.

By marking the entire body text by manual operations, for example by swiping with the mouse pointer, each character of the body text and / or the background is assigned the color contained in the tag. Only then is the access code visible on the window surface.

This may be triggered by any interaction of the receiving computer where the service operator desires to ensure that the input is from a human.

For further protection, it is possible to supplement the graphic containing an access code in the sequence of characters by further geometric structures which superimpose the sequence of numbers, letters and / or characters.

Likewise, it is within the meaning of the invention if the characters and geometric figures contained in the graphic have different colors, which are noted in a CSS code and assigned to the letters of the body text.

In the following, the invention will be explained in the form of an embodiment.

First, a base graph is created from four random numbers or letters and added with additional dashes. This graphic can be chosen almost arbitrarily.

Then a script captures this graphic. Based on a set width, the image is scaled and rasterized.

Now a text that has been created at random is strung together so that it is as many lines long as the graphic is high and that each line has as many characters as the graphic is long.

Now, all the existing colors are searched in the image and a CSS code is created for each new color, so that the text, if marked, receives this new color of the image both as text and as background color.

Then, for each letter, load the color that has the pixel of the image at the point where the letter is. The letter is then provided with a formatting tag for the corresponding color and output.

The result is delivered to the user in the form of an HTML page that opens up separately.

At the end the user only reads the text.

However, as soon as he marks the text, the browser orients itself to the colors set for each individual letter in case of marking are. This creates an image of the image in the form of text.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011012471 A [0011]
• DE 112010002445 T5 [0013]
• US 6195698 B1 [0015]

Claims (3)

CAPTCHA distinguishes between computers and people interacting with computers to prevent unwanted effects of an external computer using automated access programs, especially those known as spybots or spam servers, through a fully automatic Turing test to distinguish computers and humans, generally CAPTCHA designated, characterized in that a graphic, which consists of a sequence of numbers, letters and / or characters and forms an access code in its sequence is arranged on a surface having a predetermined length and height, and that in a continuous text whose line length the Number of pixels of the width of the graphic and its number of lines corresponds to the number of pixels of the height of the graphic, the individual characters of the continuous text is assigned by means of a formatting tag a color that corresponds to the color of the respective pixel of the graphic and which can be activated only when marking the body text is that the body text is attached as an HTML file to the file to be backed up and transmitted to the recipient computer so that it opens in a separate window when activating the file to be backed up, that the entire body text can be marked by manual operations, each letter of the body text and / or the background is assigned the color contained in the tag so that the access code becomes visible on the window surface and this can be entered into the file to be backed up. CAPTCHA according to claim 1, characterized in that the graphic containing an access code in the sequence of characters contains further geometric structures superimposed on the sequence of numbers, letters and / or characters. CAPTCHA according to claim 1 and / or 2, characterized in that the characters and geometric figures contained in the graphic have different colors, which are noted in a CSS code and can be assigned to the letters of the body text when marking.