Patent Publication Number: US-2017357313-A1

Title: Multi-user eye tracking using multiple displays

Description:
This application is a continuation of U.S. patent application Ser. No. 14/369,518, filed on Jun. 27, 2014, which is a U.S. National Stage Application under 35 U.S.C 371 from International Application No. PCT/US2013/076514, filed on Dec. 19, 2013, each of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND ART 
     Users often use multiple display surfaces. With technologies such as Display as a Service (DaaS), the user has increased options for mixing and matching display surfaces with content delivery locally as well as remotely and with environments having multiple viewers. With DAAS, people can view what&#39;s on their tablet on a big-screen television, mirror the same imagery on multiple displays either locally or across the Internet, or link up multiple displays to create a single, bigger display. A challenge exists regarding displaying and sharing of sensitive content with a trusted party; given these environmental circumstances is it becomes easy for passers-by to observe shared sensitive content both from the content owner&#39;s display as well as from collaborators&#39; displays. 
     Existing solutions offer eye tracking with display obfuscation solutions where a single display is protected using an eye tracking camera integrated with a graphics display controller that obfuscates the frame buffer content except in the areas of the screen where the viewer fixates. In some embodiments, the graphics controller displays non-obfuscated frame buffer information for the duration of the user fixation. 
     Working with multiple display surfaces can be challenging. What is needed is a system and method for displaying information to a second (or third) collaboration partner while also preventing eavesdropping by passers-by. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements. 
         FIGS. 1 and 2  illustrate multi-user eye tracking systems; 
         FIG. 3  illustrates displays within a multi-user eye tracking system; and 
         FIG. 4  illustrates another multi-user eye tracking system; 
         FIGS. 5 a  and 5 b    illustrate an example eye tracking method; and 
         FIG. 6  is a block diagram illustrating an example machine upon which any one or more of the techniques (e.g., methodologies) discussed herein may perform, according to an example embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Computer displays are the window into sensitive information stored on computer systems. Access control mechanisms are used to verify the identity of people accessing that information, but data being reviewed by qualified personnel is still subject to being seen by eavesdroppers looking over their shoulders. As noted above, obfuscation solutions have been used to limit the ability of a passer-by to look over the shoulder of qualified users on single displays, but no mechanism has been proposed for extending such capabilities to qualified observers on other displays. 
       FIG. 1  illustrates a multi-user eye tracking system  100 . System  100  of  FIG. 1  includes a computing system  102  connected to two or more displays  106 . Computer system  102  includes a processor  120  and two display controllers  116 . Each display controller  116  includes a frame buffer  118  used to provide content to displays  106 . 
     Adjacent to or integrated into each display  106  (such as display  106 . 1  and  106 . 2  in  FIG. 1 ) is a camera  108  connected to a processor  120  in computer system  102 . In some embodiments, an input device  110  (such as, for example, a keyboard or a mouse) is connected to processor  120  as well. 
     In some embodiments, information displayed on display  106 . 1  is mirrored on display  106 . 2 , and obfuscation solutions are extended across displays  106 . 1  and  106 . 2  to prevent eavesdropping on either display  106 . In one such embodiment, processor  120  transfers data from frame buffer  118 . 1  to frame buffer  118 . 2  to mirror the content of display  106 . 1  on display  106 . 2 , while each display controller  118  includes obfuscation hardware or firmware to be able to obfuscate its associated display  106 . 
     In the example embodiment shown in  FIG. 1 , cameras  108  connected to processor  120  are configured to track eye movements of users  112  viewing displays  106 . In some such embodiments, processor  120  is configured to detect eavesdroppers  114  and to initiate obfuscation as necessary on the display  106  being viewed by eavesdropper  114 . 
       FIG. 2  illustrates another embodiment of a multi-user eye tracking system. In the example embodiment shown in  FIG. 2 , system  200  includes a computing system  102 . 1  connected to one or more displays  106 . 1 , to one or more cameras  108  and, in some embodiments, to an input device  110 . System  200  also includes a computer system  102 . 2  connected to one or more displays  106 . 2 , to one or more cameras  108  and, in some embodiments, to an input device  110 . Computer system  102 . 2  is also connected across a network  104  to computer system  102 . 1  and operates with displays  106 . 2  to provide remote replication of content displayed on displays  106 . 1 . In some embodiments, network  104  is a local area network (LAN) while in other embodiments, network  104  is a wide area network (WAN) or a combination of LAN and WAN. 
     In the example shown in  FIG. 2 , cameras  108  are placed proximate to or are integrated into each display  106  so that they can track eye movement in people  112  observing the display  106 . In some embodiments, information displayed on display  106 . 1  is mirrored on display  106 . 2 , and obfuscation solutions are extended across displays  106 . 1  and  106 . 2  to prevent eavesdropping on either display  106 . 
     In the example embodiment shown in  FIG. 2 , each computer system  102  includes a processor  120  connected to a frame buffer  122  and an I/O controller  124 . Processor  120  writes data into frame buffer  122  for display on display  106 . I/O controller  124  receives information from cameras  108  and inputs  110  for transfer to processor  120 . 
     In some embodiments, systems  100  and  200  rely on an eye tracking mechanism that integrates eye movements from all qualified observers. Eye movements can be classified as “fixations”—momentary pauses in eye movements where the subject concentrates on the subject matter; and “saccades”—frequent and erratic eye movements that seem to scan the display area searching for interesting content to focus on. These movements appear to be random. In some embodiments, the intersection of fixations of the qualified observers is used by the graphics controller (such as display controller  116 ) to determine which frame data to obfuscate or de-obfuscate. By assigning a time-to-live timer to fixations of a leader (somewhat like the concept of the GUI window with focus), the follower participants&#39; display frames will remain ‘available’ for display given the follower&#39;s natural rhythm for fixation and saccades. However, when the time-to-live timer expires, the follower sees obfuscated content implying the follower is ‘wandering’ away from content the leader intends the followers to view. This ensures the followers, though trusted, do not overly focus on content that possibly could be memorized if studied intently. Passers-by do not have the benefit of eye-tracking cameras following their eye movements and therefore are not able to synchronize their viewing pattern with that of the leader or any of the followers. 
     Working with multiple display surfaces can be challenging because eye tracking cameras can have narrow fields of view. Therefore, in some embodiments, multiple cameras  108  are used for each set of one or more displays  106  to increase field of view. Also, since user saccades and fixations occur in an apparent random ordering, in some embodiments, sensitive 3D camera technology is employed with eye tracking algorithms that follow the viewer&#39;s random eye movements. 
     In some such embodiments, 3D camera technology is embedded in the bezel of mass market displays  106  to solve the problem of insufficient numbers of cameras given multiple displays  106 . 
     Example display screens are shown in  FIG. 3 . In the example shown in  FIG. 3 , displays  300 ,  302 , and  304  represent views of a display by a Leader (e.g., user  112 . 1  in  FIG. 2 ), a Follower (e.g., user  112 . 2  in  FIG. 2 ) and an Observer/Eavesdropper ( 114  in  FIGS. 1 and 2 ), respectively. In the example shown, Leader fixations (L 0 , L 1  and L 2 ) determine the sections of the frame buffer that are not obfuscated in, for example, display  106 . 1  for the Leader. (The cross-hatching over the remainder of display  106 . 1  indicates that those areas of the display are being obfuscated.) In one embodiment, those same sections are presented without obfuscation to the Follower on display  106 . 2 , but only when the Follower&#39;s fixations (F 0 , F 1 , F 2 , F 3 , F 4  and F 5 ) intersect with recent fixations of the Leader (at, for instance, as is shown in display screen  302  in  FIG. 3 , F 0 , F 1  and F 2 ). (The cross-hatching over F 3 , F 4  and F 5  in  FIG. 3  indicates that those segments are being obfuscated. Once again, the cross-hatching over the remainder of display  106 . 2  indicates that those areas of the display are being obfuscated.) 
     In other embodiments, clear sections (L 0 , L 1  and L 2 ) presented to the Leader are only presented to the Follower when the Follower&#39;s fixations intersect with those of the Leader at approximately the same time. That is, when the Follower&#39;s eyes are looking at the same part of the display as the Leader. An example from  FIG. 3  is when the Leader&#39;s eyes are on L 1  at the same time that the Follower&#39;s eyes are on F 1 . In some embodiments, this is accomplished by setting the time-to-live timer to a small value. 
     In some embodiments, the content of the Leader&#39;s frame buffer is replicated in the frame buffer associated with display  106 . 2 , and sections of the frame buffer are obfuscated as noted above. Fixations may vary but where they intersect with leader fixations they are visible in the Follower&#39;s frame buffer. In some embodiments, saccades (such as saccades A 0 -A 3  in display screens  300  and  302 ) do not affect visible content. 
     Observer  114  eye movements are not tracked and, therefore, Observers  114  cannot easily glean content by observing either the Leader display  300  or the Follower display  302 . Observer  114  therefore sees something like Observer display  304 . That is, the entire display is, to his eyes, obfuscated whether it is display  106 . 1  or  106 . 2 . 
       FIG. 4  illustrates another embodiment of a multi-user eye tracking system. In the example embodiment shown in  FIG. 4 , system  400  includes a computing system  102 . 1  connected to one or more displays  106 . 1  via a display controller  130 . Display controller  130  includes a frame buffer  140  which stores data to be displayed on display  106 . 1 . In some embodiments, display controller  130  and frame buffer  140  are integrated into computer system  102 . 1 . 
     In some embodiments, computer system  102 . 1  is a personal computer. Other computing systems, such as a server or an embedded controller could be used for computing system  102 . 1  as well. In the embodiment shown in  FIG. 4 , an eye tracking controller  132  connected to one or more cameras  108  is used to determine the segments  142  of frame buffer  140  to obfuscate on display  106 . 1 . 
     As shown in  FIG. 4 , system  400  also includes a display controller  134  connected to display controller  130  via a frame buffer transfer engine (such as DaaS engine  136 ). Display controller  134  includes a frame buffer  144  which stores data to be displayed on display  106 . 2 . In some embodiments, DaaS engine  136  conveys some or all of the contents of frame buffer  140  to frame buffer  144  as needed. 
     In the embodiment shown in  FIG. 4 , an eye tracking controller  138  connected to one or more cameras  108  is used to determine the segments  146  of frame buffer  144  to obfuscate on display  106 . 2 . Eye tracking controllers  132  and  138  can be implemented in firmware in cameras  108 , in the corresponding computing systems  102 , or on embedded controllers within, for instance, display controller  130  or display controller  134 . In some example embodiments, eye tracking controllers are run in a trusted execution environment such as the Manageability Engine or the Security Engine, both available from Intel Corporation. 
     In some such embodiments, the content displayed is content replicated from frame buffer  140 . In such cases, portions of content from frame buffer  140  are displayed without obfuscation when the Leader&#39;s eye movements and the Follower&#39;s eye movements fall within the same sections of their corresponding displays  106 . For instance, as is shown on  FIG. 4 , when the Leader&#39;s eyes fall on L 0  and the Follower&#39;s fall on F 0 , the segment  146  corresponding to F 0  is displayed on display  106 . 2 . In some such embodiments, there is some persistence built into the system such that when the Leader fixates on a new area (such as L 1 ), the Follower is able to continue viewing F 0  for a period of time. In some embodiments, that period of time is stored as a value (such as the time-to-live value discussed above). 
     In the embodiment shown, computer system  102 . 2  connected to one or more displays  106 . 2 , to one or more cameras  108  and, in some embodiments, to an input device  110 . Computer system  102 . 2  is also connected across a network  202  to computer system  102 . 1  and operates with displays  106 . 2  to provide remote replication of content displayed on displays  106 . 1 . 
     In one embodiment, non-obfuscated frame buffer contents corresponding to Leader fixations are marked within the frame buffer  140  (at, for instance, L 0 ). DaaS Engine  136  copies non-obfuscated frame buffer fixations (L 0 , L 2 , L 4  and L 6 ) to Follower display controller  134  where they are interleaved with Follower fixations (F 0 , F 2 , F 4  and F 6 ). In some embodiments, the intersection of Leader and Follower fixations determines the subsets of the frame buffer  144  that are not obfuscated. 
     In some embodiments, eye tracking controller  132  uses a 3D camera  108  (typically embedded in the bezel of the display) to view eye movements. Eye tracking controller  132  cooperates with display controller  130  to identify the subset of the display frame corresponding to the fixation regions. This computation is performed quickly (e.g., &lt; 1/60th second) so that the user does not perceive a blind spot or flicker. In some embodiments, frame buffer segments  142  not correlated with a fixation are obfuscated using a display buffer mask. In one embodiment, content is obfuscated by XOR&#39;ing the mask into the display frame contents so that any observer who is not being tracked by eye tracking will not be able to observe meaningful content. In some embodiments, obfuscating includes replacing segments in the second display controller&#39;s frame buffer with random characters. In some embodiments, the obfuscation mechanism is embedded in the display controllers. 
     In some embodiments, a user  112 . 1  may employ multiple monitors  106  where the eye tracking for each display is tuned to that user  112 . 1 . In some such embodiments, display controllers  130  and  134  cooperate to negotiate “fixation” frames corresponding to the appropriate display frames. For example, in a situation when user  112 . 1  has two displays  106 , while user  112 . 2  has only a single display  106 , when user turns from the first display  106  to the second display  106 , the display  106  of user  112 . 2  automatically switches to display the contents of the second display of user  112 . 1 . In one such embodiment, the non-obfuscated fixation frames can be shared with a trusted Follower using Display-as-a-Service (DaaS) engine  136  which distributes content to multiple displays/individuals. In one such embodiment, DaaS engine  136  relies on a content source—in this case Leader display controller  130 . The DaaS engine  136  feeds leader frames to follower display controllers  134  where follower eye tracking controllers  138  identify fixation regions that overlap (intersect) the DaaS engine  136  supplied frames. In one embodiment, DaaS engine  136  assigns a time-to-live value to Leader frames and may expire those frames after the interval expires to prevent followers from focusing too much on frames not being observed by the leader. In this fashion, the leader can control what is being displayed to others simply by looking at the content he wants them to view. 
     It may be possible for an observer to use a camera, Google Glass™, or a video recording device to capture non-obfuscated screen content. Such a screen scraping attack still exists in systems  100 ,  200  and  400 . To combat scraping attacks, in some embodiments eye tracking controllers  132  and  138  use observer detection methods; the methods allow individuals within the field of view of the display  106  to identify over-the-shoulder observers, observers wearing glasses or other electronic recording devices. In some such embodiments, Leaders and Followers are notified of such intrusions and given the option of blanking the screen until the environment is safer. 
     A method of eye tracking is shown in  FIG. 5 . In the example embodiment of  FIG. 5 , an image in front of Leader&#39;s display  106 . 1  is captured at  500  and processed at  502  for human features. If eye features are found at  504 , control moves through  506  to  508 . Otherwise, control moves back to  500 . At  508 , pupil motion is extracted and used, at  510 , to update a pupil motion delta model. 
     A check is made at  512  to determine if the pupil motion was a saccade. If so, control moves back to  508 . If, however, the check at  512  determines that the pupil motion was not a saccade, control moves to  514  and x, y, and z coordinates for eye features are fed to a display renderer. Leader frame buffer position is set at  516 , and control moves to  540 . 
     Frame buffers outside the view radius of display  106 . 1  are obfuscated at  540  and information regarding the areas viewable within the Leader&#39;s display  106 . 1  are captured at  542 . 
     Meanwhile, an image in front of a Follower&#39;s display  106 . 2  is captured at  520  and processed at  522  for human features. If eye features are found at  524 , control moves through  526  to  528 . Otherwise, control moves back to  520 . At  528 , pupil motion is extracted and used, at  530 , to update a pupil motion delta model. 
     A check is made at  532  to determine if the pupil motion was a saccade. If so, control moves back to  528 . If, however, the check at  532  determines that the pupil motion was not a saccade, control moves to  534  and x, y, and z coordinates for eye features are fed to a display renderer. Follower frame buffer position is set at  536 , and control moves to  544 . 
     At  544 , the leader frame buffer is merged with the follower frame buffer to form a shared output display and then the shared output display is displayed on display  106 . 2  at  546 . 
       FIG. 6  is a block diagram illustrating a machine in the example form of a computer system  102 , within which a set or sequence of instructions may be executed to cause the machine to perform any one of the methodologies discussed herein, according to an example embodiment. In alternative embodiments, the machine operates as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine may operate in the capacity of either a server or a client machine in server-client network environments, or it may act as a peer machine in peer-to-peer (or distributed) network environments. The machine may be a personal computer (PC), a tablet PC, a hybrid tablet, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. 
     Example computer system  102  includes at least one processor  1002  (e.g., a central processing unit (CPU), a graphics processing unit (GPU) or both, processor cores, compute nodes, etc.), a main memory  1004  and a static memory  1006 , which communicate with each other via a link  1008  (e.g., bus). The computer system  102  may further include a video display unit  1010 , an alphanumeric input device  1012  (e.g., a keyboard), and a user interface (UI) navigation device  1014  (e.g., a mouse). In one embodiment, the video display unit  1010 , input device  1012  and UI navigation device  1014  are incorporated into a touch screen display. The computer system  102  may additionally include a storage device  1016  (e.g., a drive unit), a signal generation device  1018  (e.g., a speaker), a network interface device  1020 , and one or more sensors (not shown), such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. 
     The storage device  1016  includes a machine-readable medium  1022  on which is stored one or more sets of data structures and instructions  1024  (e.g., software) embodying or utilized by any one or more of the methodologies or functions described herein. The instructions  1024  may also reside, completely or at least partially, within the main memory  1004 , static memory  1006 , and/or within the processor  1002  during execution thereof by the computer system  102 , with the main memory  1004 , static memory  1006 , and the processor  1002  also constituting machine-readable media. 
     While the machine-readable medium  1022  is illustrated in an example embodiment to be a single medium, the term “machine-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more instructions  1024 . The term “machine-readable medium” shall also be taken to include any tangible medium that is capable of storing, encoding or carrying instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present disclosure or that is capable of storing, encoding or carrying data structures utilized by or associated with such instructions. The term “machine-readable medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media. Specific examples of machine-readable media include non-volatile memory, including, but not limited to, by way of example, semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. 
     The instructions  1024  may further be transmitted or received over a communications network  1026  using a transmission medium via the network interface device  1020  utilizing any one of a number of well-known transfer protocols (e.g., HTTP). Examples of communication networks include a local area network (LAN), a wide area network (WAN), the Internet, mobile telephone networks, plain old telephone (POTS) networks, and wireless data networks (e.g., Wi-Fi, 3G, and 4G LTE/LTE-A or WiMAX networks). The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software. 
     Additional Notes &amp; Examples 
     Example 1 includes subject matter (such as a device, apparatus, or machine) for securing data displayed to two or more individuals on two or more displays, wherein the two or more displays include a first display and a second display, comprising determining one or more fixations of a first individual on the first display, determining one or more fixations of a second individual on the second display, associating a first frame buffer with the first display, associating a second frame buffer with the second display, displaying, on the first display, segments of the content in the first frame buffer corresponding to one or more of the fixations of the first individual on the first display while obfuscating other segments shown on the first display, and displaying, on the second display, segments of the content in the first frame buffer corresponding to one or more of the fixations of the second individual on the second display while obfuscating other segments of the first buffer being shown on the second display. 
     In Example 2, the subject matter of Example 1 may optionally include, determining intersections of fixations by the first individual on the first display with fixations of the second individual on the second display and displaying, on the second display, segments of the first frame buffer corresponding to the intersection of the fixations by the first individual on the first display with the fixations of the second individual on the second display. 
     In Example 3, the subject matter of Example 1 may optionally include, wherein obfuscating includes applying an XOR mask to segments of the frame buffer. 
     In Example 4, the subject matter of Example 1 may optionally include, wherein obfuscating includes replacing segments in the second display controller&#39;s frame buffer with random information. 
     In Example 5, the subject matter of Example 1 may optionally include, at least one machine readable medium comprising a plurality of instructions that in response to being executed on a computing device, cause the computing device to carry out a method according to the subject matter of any one of examples 1, 2, 3 or 4 above. 
     Example 6 includes an eye-tracking system, comprising first and second displays; a first camera placed to capture eye movements of a first individual watching the first display; a second camera placed to capture eye movements of a second individual watching the second display; a processor, wherein the processor determines one or more fixations of the first individual on the first display and one or more fixations of the second individual on the second display; a first display controller connected to the first display, wherein the first display controller includes a frame buffer having two or more segments, wherein the controller displays segments of the frame buffer corresponding to fixation locations determined for the first individual and obfuscates display of other segments of the frame buffer; and a second display controller connected to the second display, wherein the second display controller includes a frame buffer having two or more segments, wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding to fixation locations determined for the first individuals on the first display and fixation locations determined for the second individuals on the second display and obfuscates display of other segments of the second display controller&#39;s frame buffer. 
     In Example 7, the subject matter of Example 6 may optionally include, wherein the processor copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer and wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding to what the first individual is viewing on the first display. 
     In Example 8, the subject matter of Example 6 may optionally include, wherein the processor copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer and wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding the second individual&#39;s fixations on the second display and corresponding to what the first individual is viewing on the first display. 
     In Example 9, the subject matter of any of Examples 6, 7 or 8 may optionally include, wherein obfuscating includes applying an XOR mask to segments of the frame buffer. 
     In Example 10, the subject matter of any of Examples 6, 7 or 8 may optionally include, wherein obfuscating includes replacing segments in the second display controller&#39;s frame buffer with random characters. 
     Example 11 includes an eye-tracking system, comprising first and second displays; a first camera placed to capture eye movements of a first individual watching the first display; a second camera placed to capture eye movements of a second individual watching the second display; a first processor, wherein the first processor determines one or more fixations of the first individual on the first display; a second processor which can be connected to the first processor, wherein the second processor determines one or more fixations of the second individual on the second display; a first display controller connected to the first display, wherein the first display controller includes a frame buffer having two or more segments, wherein the controller displays segments of the frame buffer corresponding to fixation locations determined for the first individual and obfuscates display of other segments of the frame buffer; and a second display controller connected to the second display, wherein the second display controller includes a frame buffer having two or more segments, wherein the second display controller displays, on the second display, segments of the second display controller&#39;s frame buffer corresponding to fixation locations determined for the first individuals on the first display and fixation locations determined for the second individuals on the second display and obfuscates display of other segments stored in the second display controller&#39;s frame buffer. 
     In Example 12, the subject matter of Example 11 may optionally include, wherein the second processor copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer and wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding to what the first individual is viewing on the first display. 
     In Example 13, the subject matter of Example 11 may optionally include, wherein the second processor copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer and wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding the second individual&#39;s fixations on the second display and corresponding to what the first individual is viewing on the first display. 
     In Example 14, the subject matter of any of Examples 11, 12 or 13 may optionally include, wherein obfuscating includes applying an XOR mask to segments of the frame buffer. 
     In Example 15, the subject matter of any of Examples 11, 12 or 13 may optionally include, wherein obfuscating includes replacing segments in the second display controller&#39;s frame buffer with random information. 
     In Example 16, the subject matter of Example 11 may optionally include, wherein the second processor and the first processor cooperate to form a Display as a Service (DaaS) engine, wherein the DaaS engine copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer. 
     Example 17 includes an eye-tracking system, comprising first and second displays; a first camera placed to capture eye movements of a first individual watching the first display; a second camera placed to capture eye movements of a second individual watching the second display; a first eye tracking controller connected to the first camera, wherein the first eye tracking controller determines one or more fixations of the first individual on the first display; a second eye tracking controller connected to the second camera, wherein the second processor determines one or more fixations of the second individual on the second display; a first display controller connected to the first display, wherein the first display controller includes a frame buffer having two or more segments, wherein the controller displays segments of the frame buffer corresponding to fixation locations determined for the first individual and obfuscates display of other segments of the frame buffer; a second display controller connected to the second display, wherein the second display controller includes a frame buffer having two or more segments, wherein the second display controller displays, on the second display, segments of the second display controller&#39;s frame buffer corresponding to fixation locations determined for the first individual on the first display and obfuscates display of other segments stored in the second display controller&#39;s frame buffer; and a frame buffer transfer engine, wherein the frame buffer transfer engine copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer and wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding to what the first individual is viewing on the first display. 
     In Example 18, the subject matter of Example 17 may optionally include, wherein the second processor copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer and wherein the second display controller displays segments of the second display controller&#39;s frame buffer corresponding the second individual&#39;s fixations on the second display and corresponding to what the first individual is viewing on the first display. 
     In Example 19, the subject matter of Examples 17 or 18 may optionally include, wherein obfuscating includes applying an XOR mask to segments of the frame buffer. 
     In Example 20, the subject matter of Examples 17 or 18 may optionally include, obfuscating includes replacing segments in the second display controller&#39;s frame buffer with random information. 
     In Example 21, the subject matter of Example 17 may optionally include, wherein the frame buffer transfer engine includes a DaaS engine, wherein the DaaS engine copies content from the first display controller&#39;s frame buffer to the second display controller&#39;s frame buffer. 
     In Example 22, the subject matter of Examples 17, 18 or 21 may optionally include, wherein segments that are not obfuscated remain that way for a defined period of time after the first individual stops fixating on that segment. 
     Example 23 includes an eye-tracking system, comprising a first display; a first camera system placed to capture eye movements of a first individual watching the first display; a first eye tracking controller connected to the first camera, wherein the first eye tracking controller determines one or more fixations of the first individual on the first display; a display controller connected to the first display, wherein the display controller includes a frame buffer having two or more segments, wherein the display controller is capable of receiving frame buffer information from a different eye tracking system and of displaying the received frame buffer information on the first display, wherein displaying includes displaying segments of the frame buffer information corresponding to fixation locations determined for a second individual on a different display and obfuscating display of other segments of the received frame buffer information. 
     In Example 24, the subject matter of Example 23 may optionally include, wherein displaying segments includes obfuscating segments where there is insufficient overlap between the fixations of the first and second individuals on the first and second displays, respectively. 
     Example 25 includes subject matter (such as a device, apparatus, or machine) for securing data displayed to two or more individuals on two or more displays, wherein the two or more displays include a first display and a second display, the method comprising determining one or more fixations of a first individual on the first display, determining one or more fixations of a second individual on the second display; associating a first frame buffer with the first display; associating a second frame buffer with the second display; copying content from the first frame buffer to the second frame buffer; displaying, on the first display, segments of the content in the first frame buffer corresponding to one or more of the fixations of the first individual on the first display while obfuscating other segments shown on the first display; and displaying, on the second display, segments of the content in the first frame buffer corresponding to one or more of the fixations of the second individual on the second display while obfuscating other segments of the first buffer being shown on the second display. 
     In Example 26, the subject matter of Example 25 may optionally include wherein displaying on the second display includes determining intersections of fixations by the first individual on the first display with fixations of the second individual on the second display; and displaying, on the second display, segments of the first frame buffer corresponding to the intersection of the fixations by the first individual on the first display with the fixations of the second individual on the second display. 
     In Example 27, the subject matter of Example 25 may optionally include, wherein obfuscating includes applying an XOR mask to segments of the frame buffer. 
     In Example 28, the subject matter of Example 25 may optionally include, wherein obfuscating includes replacing segments in the second display controller&#39;s frame buffer with random information. 
     Example 29 includes subject matter (such as a device, apparatus, or machine) for obfuscating data, comprising capturing eye movements of a first individual watching a first display; determining one or more fixations of the first individual on the first display; receiving frame buffer information from an external source; and displaying the received frame buffer information on the first display, wherein displaying includes displaying segments of the frame buffer information corresponding to fixation locations determined for a second individual on a different display and obfuscating display of other segments of the received frame buffer information. 
     In Example 30, the subject matter of Example 29 may optionally include, wherein displaying segments includes obfuscating segments where there is insufficient overlap between the fixations of the first and second individuals on the first and second displays, respectively. 
     The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments that may be practiced. These embodiments are also referred to herein as “examples.” Such examples may include elements in addition to those shown or described. However, also contemplated are examples that include the elements shown or described. Moreover, also contemplate are examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. 
     Publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) are supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls. 
     In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to suggest a numerical order for their objects. 
     The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with others. Other embodiments may be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is to allow the reader to quickly ascertain the nature of the technical disclosure, for example, to comply with 37 C.F.R. §1.72(b) in the United States of America. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. However, the claims may not set forth every feature disclosed herein as embodiments may feature a subset of said features. Further, embodiments may include fewer features than those disclosed in a particular example. Thus, the following claims are hereby incorporated into the Detailed Description, with a claim standing on its own as a separate embodiment. The scope of the embodiments disclosed herein is to be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.