NL1036976C2 - METHOD OR SECURING ENTRY OR AN ALPHANUMERIC CODE ON A COMPUTER SYSTEM, INTERACTION AND DEDICATED DRIVER ENTITY THEREFOR. - Google Patents

Description

Title:

Method of securing entry of an alphanumeric code on a computer system, interaction and dedicated driver entity therefor.

5 The present invention is directed to a method of securing entry of an alphanumeric code on a computer system comprising a display screen and a screen based entry device, wherein said screen based entry device is arranged for enabling interaction between said computer system and a user by selecting information displayed on said screen in operation, said method comprising the steps of: an 10 interaction entity providing graphical data to said display screen, wherein said graphical data represents images for displaying one or more alphanumeric characters on said screen on randomized positions, for selection by said user; displaying said one or more alphanumeric characters on said screen on said randomized positions for selection by said user; and said interaction entity receiving 15 input signals from said entry device, which input signals are indicative of selected characters of said alphanumeric characters.

The present invention is further directed to an interaction entity for use in such a method.

The banking industry has put an enormous amount of effort in 20 security procedures for securing electronic banking activities. One of the areas of focus is the entry of personal identification numbers (PIN) in automatic teller machines (ATM’s) or point of sale (POS) terminals . Similarly, security procedures are also an area of focus in the telecommunications and computer industry, for example for securing entry of passwords and the like in computer systems.

25 An unexplored possibility in the field of electronic banking is the direct entry of personal identification numbers (PIN) in computer systems, e.g. for online banking. The direct entry of PIN numbers in a computer system has been largely avoided by the banking industry, as it poses a potential security risk to both the bank and the user of the PIN code. Computer systems can easily be tampered 30 with, such as to perform various types of undesired logging methods for fraudulently and unauthorised acquiring of the PIN number of the user.

A solution to this problem for the entry of PIN numbers using screen based entry devices (such as a computer mouse or touch screen) is to display an alphanumeric keypad on the screen wherein the alphanumeric characters on the 1036976 2 keypad are placed in positions that are not predictable to a user. In other words, the positions of the alphanumeric characters is randomized in the keypad displayed on screen. Position and displacement logging of mouse clicks by fraudulent software installed on the computer systems in that case does not reveal the entered PIN 5 code, since the alphanumeric characters on the keypad are in randomized positions. Therefore if the position of a mouse click is known, it can no longer be linked to a corresponding alphanumeric character selected by the user.

A problem with the above described method is formed by the fact that more sophisticated logging software may be designed to take screen shots from 10 the screen and may, in combination with position logging, reveal the link between the position of the mouse click and the alphanumeric character on screen which is selected by the user. The PIN number can thereby be retrieved by the fraudulent software. Preventing screen logging is difficult since within a computer system, taking screen shots is a standard feature made available by the operating system.

15 The present invention has for its object to solve the above mentioned problem of the prior art, and to provide secure and tamper proof method of entering an alphanumeric code on a computer system.

The above object is achieved by the present invention in that there is provided a method of securing entry of an alphanumeric code on a computer 20 system comprising a display screen and a screen based entry device, wherein said screen based entry device is arranged for enabling interaction between said computer system and a user by selecting information displayed on said screen in operation, said method comprising the steps of: an interaction entity providing graphical data to said display screen, wherein said graphical data represents images 25 for displaying one or more alphanumeric characters on said screen on randomized positions, for selection by said user; displaying said one or more alphanumeric characters on said screen on said randomized positions for selection by said user; and said interaction entity receiving input signals from said entry device, which input signals are indicative of selected characters of said alphanumeric characters; 30 wherein said images are distorted such as to prevent unauthorised screen-capturing of said alphanumeric characters.

By randomizing the position of characters on the screen, the logging of mouse click no longer leads to an indication of the character selected by the user. Moreover, since the images that are provided to the display screen are distorted, it 3 will not be possible to retrieve meaningful graphical information from taking screen shots. Taking a screen shot will yield only a distorted version of the image seen by the user. From this distorted image no information can be retrieved on the specific alphanumeric characters and their location on the screen.

5 According to an embodiment of the invention, the images are formed in a distorted manner by the interaction entity. In this embodiment, the interaction entity assembles the graphical data, by forming the images containing the alphanumeric characters and by putting the images into a sequence. The images are thereby formed such that the alphanumeric characters are distorted or 10 misformed such as to prevent unauthorised screen capturing of the characters.

According to another embodiment of the invention, the graphical data is distorted prior to providing the graphical data to the display screen. In this embodiment, the images are formed by the interaction entity and are put into a sequence for providing the graphical data, but the graphical data is distorted after 15 assembling thereof and prior to providing it to the display screen. The graphical data is distorted such that the alphanumeric characters in the images cannot be read when an unauthorised screen capture is taken.

In accordance with a preferred embodiment, the graphical data represents a sequence of images for displaying on the screen, and the images are 20 distorted such that two or more consecutive images comprise fractions of the alphanumeric characters. In a special embodiment thereof, these fractions are complementary fractions that together form at least one of the alphanumeric characters. By providing complementary fractions within consecutive images of the sequence carried by the graphical data, these complementary fractions are 25 displayed on the display screen, one after the other. Since the images are displayed with a high refresh rate the human eye is not able to resolve the individual images. The human eye of the user will perceive these images as one composite image of all the complementary fractions, presenting the alphanumeric character which is hidden in each of the individual images.

30 It will be interesting to appreciate, that in accordance with the invention this is not the only manner in which the results of the invention can be achieved. Consecutive images may also be formed by, for example, individual seemlessly random shapes of carefully selected colours. Perception by the human eye interprets the composite image as containing the ‘hidden’ alphanumeric 4 character since the shapes and colours in each of the consecutive images blend together in the composite image. For example, a white coloured shape in a first image which overlaps a black coloured and different shape in a second image yields a grey coloured overlap shape in the composite image. Therefore, carefully 5 selecting the individual shapes and colours in each of the consecutive images may construct the hidden alphanumeric character in the composite image by means of blending the shapes, as interpreted by the human eye.

According to a further embodiment the individual fractions are formed such as to be unrecognisable for identifying the alphanumeric characters. It 10 will be understood that once the fractions shown in a single of the consecutive images is recognisable as a part of a known alphanumeric character, the alphanumeric character can be identified by performing an unauthorised screen capture at a convenient time. This would pose a security risk.

In accordance with a further embodiment of the present invention, 15 the fractions may be of different colours. By providing the fractions at different colours, this complicates the identification by unauthorised persons even further, as it may not be clear whether or not a fraction shown in the image is a part of the alphanumeric character on the screen.

In accordance with a further embodiment, the fractions are 20 randomly formed shapes. As will be understood, the images may further comprise randomly formed further objects which are to mislead an unauthorised person taking a screen capture from identifying the alphanumeric character.

It will be apparent to the skilled person that the interaction entity may be implemented as a hardware component on a computer system. However, it 25 is also possible to implement this entity as a software component.

In accordance with the second aspect of the present invention, there is provided an interaction entity for use in a method as described above, said entity being arranged for enabling secure entry of an alphanumeric code on a computer system comprising a display screen and a screen based entry device, said 30 entity comprising means for providing graphical data to said display screen, for displaying one or more alphanumeric characters on said screen based on said graphical data for selection by said user, and means for receiving input signals from said entry device, which input signals are indicative of selected characters of said alphanumeric characters, wherein said means for providing said graphical data are 5 arranged for including in said graphical data screen position data for displaying said alphanumeric characters on said screen on randomized positions, and wherein said interaction entity further comprises means for entity encoding said graphical data prior to providing said graphical data to said display screen such as to prevent 5 unauthorised logging of said graphical data.

The present invention will now further be elucidated by means of some specific examples, with reference to the enclosed drawings, wherein: figure 1 provides an example of a randomized keypad displayed on a screen; 10 figure 2 provides an example of a computer system comprising an interaction entity and dedicated driver entity according to the present invention; figures 3A-3D illustrate a set of consecutive images in accordance with the invention; figure 3E illustrates the composite image of the images of figures 15 3A-3D.

In figure 1 a randomized keypad is displayed, that may be used in accordance with the present invention. In the keypad displayed, the position of alphanumeric characters for selection by the user is randomized. The keypad 1 comprises for example key 2 for selecting the alphanumeric character “9". The 20 position of this character “9" is different from the position where one would intuitively expect it to be (namely on key 5, where the alphanumeric character “2" is located). In accordance with the present invention after each 'key stroke’, i.e. selection of a alphanumeric character by the user, the location of the alphanumeric characters can be randomized anew, Also, the position of the keypad 1 on the screen may be varied 25 after each key stroke.

After entering the requested security code (e.g. personal identification number), the user may confirm that entry is completed by selecting ΌΚ’ on position 3 of the keypad 1. The user may at any time decide to terminate the entry procedure by pressing ‘cancel’ on position 4 of the keypad 1. The keys 3 and 4 30 for ΌΚ’ and ‘cancel’ respectively are at fixed positions in keypad 1 illustrated in figure 1. The positions of these keys 3 and 4 may however be randomized as well to hinder mouse logging even more, and to prevent discovery of the number of digits of the code entered by means detecting selection of the ‘OK’ button.

In figure 2 there is illustrated a computer system 10 comprising an 6 interaction entity in accordance with the present invention. Computer system 10 comprises a computer 11 (which may be a regular personal computer) comprising an input/output unit 14 for receiving input from input devices such as computer mouse 17. The signal received from computer mouse 17 is provided to the central 5 processing unit of the computer (not shown) which may be provided to interaction entity 22 for further processing. Interaction entity 22 is responsible for providing graphical data to the display screen 15 such as to display an alphanumeric keypad (such a keypad 1 of figure 1) on the display screen 15. The graphical data provided to the display screen 15 comprises a sequence of images to be displayed on the 10 display screen 15. The position of the alphanumeric keypad itself may be randomized, but at least the position of the alphanumeric characters within the keypad is randomized as described above. This is controlled by the interaction entity 22.

Interaction entity 22 provides the graphical data to graphical 15 processing device 16 which uses its graphical processing unit 20 for transforming the received images into a suitable electronic signal for driving the display screen 15. In accordance with a preferred embodiment, the images are formed by interaction entity 22. These images are distorted, or at least comprise distorted alphanumeric characters, such that none of the individual images provides sufficient 20 information for identifying the alphanumeric characters.

An example of the invention is illustrated in figures 3A-3E. Figure 3E shows a key in a keypad which contains the number '9'. Figure 3E is the composite image as perceived by the human eye when looking at the display screen on which the key pad is displayed. In reality, the graphical data provided to the 25 display screen comprise consecutive images 3A, 3B, 3C and 3D respectively.

In figure 3A, the key is shown in dotted lined box 30. This image only comprises fractions 31 and 32 of the alphanumeric character ‘9' reformed. In box 35 of figure 3B it is shown that the image that follows the image of figure 3A comprises only fractions 36 and 37. The image in box 40 of figure 3C comprises 30 fractions 41, 42 and 43 and the image in figure 3D, box 45, comprises fractions 46, 47 and 48. None of the individual images 3A-3D reveals sufficient information by itself from which the number can be identified. Figure 3C shows most of the fractions, but from the fractions shown in figure 3C alone, the alphanumeric character formed could still be a ‘5', '6', ‘8' or ‘9’, or a letter such as the 'S’ or 'B'.

7

Since all the keys in the keypad comprise distorted alphanumeric characters at randomised locations, taking a screen capture in an attempt to identify the alphanumeric characters on each of the keys is pointless. If all the fractions of figures 3A, 3B, 3C and 3D are put together, the alphanumeric character ‘9’ of figure 5 3E is formed as is shown in box 50.

The above described specific example uses fractions of the alphanumeric character in a single colour. It will be understood that the images can be enriched by false misleading fractions. In addition, it is not even necessary to use fractions of the alphanumeric character to be shown. Use can also be made of 10 complementary carefully selected forms of carefully selected colours that blend into one in the composite image such as to form a recognisable alphanumeric character. Many other solutions are possible within the teachings of the present invention. Consecutive images may be made of seemlessly random spots that blend into a single alphanumeric character in the composite image. Use can also be made of 15 complementary colours that blend into a different colour revealing the alphanumeric character hidden in each of the images.

The invention is based on the insight that by both randomising the locations of the key and the keypad on the screen, and distorting the alphanumeric character provided to the screen in each image, makes it virtually impossible to 20 successfully apply logging methods in order to reveal a security code entered. Therefore, the present invention enables the entry of security codes in a safe and secure manner within a virtual computer environment that is not necessarily secured and that may be accessible to unauthorised persons.

In the above detailed description for purposes of explanation and 25 not limitation, example embodiments disclosing specific details were set forth in order to provide a thorough understanding of embodiments according to the present teachings. However, it will be apparent to one having ordinary skills in the art having had the benefit of the present disclosure, that other embodiments according to the present teachings that depart from the specific details disclosed herein, remain 30 within the scope of the teachings. Moreover, although descriptions of well known apparati and methods have been omitted so as not to obscure the description of the example embodiments, such methods and apparati are clearly within the scope of the present teachings. The scope of the invention is determined by the appended claims.

1036976

Claims (14)

A method for securing input of an alphanumeric code on a computer system comprising an input screen and a screen-based input unit, the screen-based input unit being adapted to release in operation interaction between the computer system and a user by means of selecting information displayed on the screen, the method comprising the steps of: providing an interaction entity with graphic data on the display screen, the graphic data representing images for displaying one or more alphanumeric characters on the display screen at random positions for selection by the user; displaying the one or more alphanumeric characters on the screen at the random positions for selection by the user; And receiving input signals from the input unit by the interaction entity, which input signals are indicative of the selected characters from the alphanumeric characters; wherein the images are distorted in such a way as to prevent unauthorized screen capturing of the alphanumeric characters. The method of claim 1, wherein the images are formed by the interaction entity in a distorted manner. 3. The method of claim 1, wherein for distorting the images, the graphic data is distorted prior to providing the graphic data to the display screen. 4. Method as claimed in any of the foregoing claims, wherein the graphic data represents a sequence of images for displaying them on the screen, and wherein the images are distorted in such a way that two or more consecutive images, as observed by a human eye include complementary fractions that form a composite image of the alphanumeric characters. The method of claim 4, wherein individual fractions are shaped so that they are not recognizable for the sake of identifying the 1036976 I, alphanumeric characters. The method of any one of claims 4-5, wherein the fractions are of different colors. The method of claim one of claims 4-6, wherein the 5 fractions are randomly formed. A method according to any one of the preceding claims, wherein the images further comprise randomly shaped objects. The method of any one of the preceding claims, wherein the interaction entity is a software component that runs on a computer system. An interaction entity for use in a method according to any one of the preceding claims, wherein the entity is adapted to release a secure entry of an alphanumeric code on a computer system comprising a display screen and a screen-based input unit, the entity comprises means for providing graphic data to the display screen, wherein the graphic data represents images for displaying one or more alphanumeric characters on the screen at random positions for selection by a user, and means for receiving input signals from the input unit, which input signals are indicative of the selected characters from the alphanumeric characters, wherein the interaction entity is arranged to distort the images so as to prevent unauthorized screen capturing of the alphanumeric characters. The interaction entity of claim 10, wherein the entity comprises means for forming the images in a distorted manner. The interaction entity according to claim 10 or 11, wherein the means for providing graphic data is arranged to contain a sequence of images for display on the screen in the graphic data, and wherein the interaction entity is arranged for distorting the images such that two or more consecutive images comprise fractions of the 30 alphanumeric characters. The interaction entity of claim 10, wherein the fractions are complementary fractions to form at least one of the alphanumeric characters. 14. Interaction entity according to any of claims 12 or 13, wherein the interaction entity is arranged to form the individual fractions such that they are unrecognizable for identifying the alphanumeric characters.