Method and system for maintaining secure data input and output

Abstract

Methods and systems for enhancing the security of data during input and output on a client computer system are provided to prevent attempts by unauthorized code to access, intercept, and/or modify data. Example embodiments provide a plurality of obfuscation techniques and security enhanced drivers that use these obfuscation techniques to prohibit unauthorized viewing/receiving of valid data. When the drivers are used together with the various obfuscation techniques, the security enhanced drivers provide mechanisms for “scheduling” the content of the storage areas used to store the data so that valid data is not available to unauthorized recipients. When unauthorized recipients attempt to access the “data,” they perceive or receive obfuscated data. The obfuscation techniques described include “copy-in,” “replace and restore,” and “in-place replacement” de-obfuscation/re-obfuscation techniques. In one embodiment, a security enhanced display driver, a security enhanced mouse driver, a security enhanced keyboard driver, and a security enhanced audio driver are provided. To complement the security enhancements, the methods and systems also provide for a watchdog mechanism to ensure that the driver is functioning as it should be and various user interface techniques for denoting security on a display device.

1 . A computer-readable memory medium containing instructions for controlling a computer processor in a computer system to ensure the secure receipt of input data from an input device, the computer system having a system input device driver code and an ordering of device driver codes such that a first device driver code gains control before the other device driver codes, by: 
 installing a modified input driver code as the first device driver code, thereby insuring that the system input device driver code does not process an input event first; and    under control of the modified input driver code, 
 receiving an input event;  
 determining whether the input event is designated as a secure input event; and  
 when it is determined that the input event is a secure input event, processing the input event.  
   
   
   
       2 . The computer-readable memory medium of  claim 1 , further controlling the computer processor by: 
 forwarding the input event to the system input event device driver code when it is determined that the input event is not a secure input event.    
   
   
       3 . The computer-readable memory medium of  claim 1  wherein the input device driver code controls a pointing device.  
   
   
       4 . The computer-readable memory medium of  claim 1  wherein the input device driver code controls a keyboard device.  
   
   
       5 . The computer-readable memory medium of  claim 1  wherein the input device driver code is responsive to an audio device.  
   
   
       6 . A computer system for ensuring the secure receipt of input data from an input device, comprising: 
 a plurality of device drivers, including a system input device driver;    a driver order control mechanism that controls the ordering of the plurality of device drivers such that a first device driver gains control before the other device drivers of the plurality of device drivers; and    a modified input device driver, installed as the first device driver using the driver order control mechanism, thereby insuring that the system input device driver code does not process an input event first, that is structured to, 
 receive an input event;  
 determine whether the input event is designated as a secure input event; and  
 when it is determined that the input event is a secure input event, process the input event.  
   
   
   
       7 . The system of  claim 6 , wherein the modified input device driver is further structured to: 
 forward the input event to the system input event device driver when it is determined that the input event is not a secure input event.    
   
   
       8 . The system of  claim 6  wherein the input device driver controls a pointing device.  
   
   
       9 . The system of  claim 6  wherein the input device driver controls a keyboard device.  
   
   
       10 . The system of  claim 6  wherein the input device driver is responsive to an audio device.