TH66596A - Systems and methods for securing video card output - Google Patents

Abstract

DC60 (18/08/46) The various methods and systems described herein aim to provide a secure pathway for the execution of software on a server. These methods and systems identify and provide solutions to attack models in which malicious software running on the server attempts to obtain or modify data improperly. Some inventions can provide pixel data that can be kept confidential (meaning that untrusted applications cannot read the information displayed on the screen). Other inventions maintain the integrity of image data by detecting whether the pixel data has been improperly modified. Many of these inventions are based on decoding mechanisms on the video card, often located at the end of the video processing group, so that programmatic access to the decoded pixel data is denied. The various methods and systems described herein aim to provide a secure pathway for the execution of software on a server. These methods and systems identify and provide solutions to attack models in which malicious software running on the server attempts to obtain or modify data improperly. Some inventions can provide pixel data... This allows for the data to be kept confidential (meaning that untrusted applications cannot read the information displayed on the screen). Furthermore, other inventions can maintain the integrity of image data by detecting whether pixel data has been improperly altered. Many of these inventions are based on decoding mechanisms on the video card, often located at the end of the video processing unit, so that programmatic access to the decoded pixel data is denied.

Claims (59)

1. A method consisting of preparing encoded video data on the video card and decoding the encoded video data to a processing location that is inaccessible to any program. 2. According to the method of claim 1, the decoding operation is performed before the decoded video data is sent to the display converter on the video card. 3. According to the method of claim 1, the decryption operation is performed before the decoded video data is sent to the RAMDAC on the video card. 4. The method of claim 1 in which decryption is performed by a hardware decoder located on the video card. 5. The method of claim 1 in which decoding is performed by a decoder located between the video card's GPU and the video card's RAMDAC. 6. One or more instructions therein that are readable by computers, when executed by one or more computers, cause one or more computers to use the methods under Claim 1. 7. A system comprising pathways for preparing video data decoding on the video card, pathways for decoding encrypted video data on the video card, and pathways for denying access to the decrypted video data by the software. 8. The system of claims in Article 7, which outlines the method for preparing the encryption of such video data, consists of stream cipher. 9. The system of claim number 7, which outlines the method for preparing the encryption of such video data, consists of a block cipher. 10. The system of claims in clause 7, the method for such decoding, consists of a hardware decoder on the video card. 11. The system comprises a graphics processing unit (GPU) for processing video data to be displayed on a screen; shared memory managed by the GPU for storing data to be processed or already processed by the GPU; a display converter (DC) for converting digital data into signals for display on the screen; and a decoder structured to decode pixel data in preparation for the DC converter. This decoder is used at the data processing location where program access to the data is not possible. 12. The system of claim 11, in which memory consists of a primary surface containing data for use in displaying an image on a display screen, contains one or more secure regions where encrypted data can be placed. 13. The system of claim number 11, which also includes the control processor on the video card specifications, will indicate the decoding capability to the decoder. 14. The system of claim 13, in which the control processor has a key manager for managing one or more keys that can be fed to the decoder for decrypting encrypted pixel data. 15. The system of claims under Article 13, which also includes a secure communication channel for connecting the control and decoding processing units. 16. The system of claim number 13, in which the control processor consists of a separate integrated circuit chip on the video card. 17. The system of claim number 11, in which the decoder consists of separate components on the video card. 18. The system comprises: video card processor paths for processing video data to be displayed on the screen; video card memory paths, which are shared memory with the processor paths for storing data to be processed or data already processed by the processor paths; video card converter paths for converting digital data into signals for display; video card decoder paths for decoding pixel data to feed to the converter paths; and video card paths for rejecting one or more applications from accessing the decoded pixel data. 19. A system consisting of a video card and video card memory, which includes a primary surface containing data to be displayed on the screen; one or more secure areas on the primary surface are used to store encrypted pixel data; and at least one key is associated with one or more areas and is configured to enable the decryption of the encrypted data. 20. The system of claims under clause 19, in which each secure area corresponds to a secure window that can be displayed on the screen. 21. The system of claims under Article 19, in which each secure area has a key that corresponds specifically to it. 22. The system of claim 21 consists of multiple secure areas, each with a different key. 23. The system of claim 19, which also includes a decoder on the video card, is structured to decode encrypted pixel data using its associated key. 24. The system of claim 23, whereby the decoder decodes the encoded pixel data to a processing location where the decoded pixel data is not accessed by the program. 25. The system of claims under Article 23, in which the decoder consists of a hardware decoder. 26. The system of claims under Article 19, in which the video card has the ability to verify its authenticity. 27. The system of claims in Article 26, in which the video card contains a digital certificate used for authentication. 28. The system of claims in clause 26, in which the video card is restructured to respond to the challenges of authentication. 29. The system of claims under Article 19, which states that the video card contains a key for encrypting communication with one or more secure application programs. 30. A procedure consisting of: defining one or more secure regions of the primary surface in the video card's memory; associating one or more keys with one or more such secure regions, suitable for encrypting pixel data stored in those secure regions; encrypting the pixel data with at least one of the aforementioned keys; and feeding the encrypted pixel data to one or more such secure regions. 31. The system of claims under Article 30 in which one or more safe areas are rectangular in shape. 32. A system of claims in clause 30 whose key contains something that can be used to encrypt using a stream cipher. 33. A system of claims in clause 30, whose key contains something that can be used to encrypt using a block cipher. 34. The method of claim 30, in which the defining action defines multiple secure areas, and the relationship action establishes relationships with each secure area using a different key. 35. The method of claim 30, in which the encryption action is performed, relies on stream encryption that is confined to one or more secure areas. 36. One or more sets of instructions therein that are readable by computers which, when executed by one or more computers, cause one or more computers to operate in the manner described in Copyright 30. 37. A system comprising a pathway for defining one or more secure regions of the primary surface in the video card's memory; a pathway for associating at least one key with one or more such secure regions, suitable for encrypting pixel data stored in those secure regions; a pathway for encrypting pixel data using at least one of the aforementioned keys; and a pathway for feeding the encrypted pixel data to one or more such secure regions. 38. The procedure consists of: preparing the encrypted data in a secure region of the primary surface on the video card; preparing a key associated with the secure region that can be used to decrypt the encrypted data; and using the key to decrypt the encrypted data in the secure region of the primary surface. 39. The method of claim 38 in which key operation occurs at a processing location where the program does not have access to the encrypted pixel data. 40. The method of claim 38 in which the key preparation is performed by the control unit on the video card. 41. The method of claim 38, which involves the use of a key for decrypting encrypted data, is performed by a hardware decoder on the video card. 42. The method of claim 38, in which the decryption key for encrypted data is operated by a decryptor on the video card capable of describing the geometric shape of the secure area. 43. The method of claim 38, which also involves feeding the decoded data to the display converter for display on the display screen. 44. The method of claim 38, which involves multiple secure areas and key input operations, provides keys that are associated with each secure area. 45. The method of claim 38, which involves multiple secure areas and key transmission operations, involves the provision of multiple keys for transmission, with each secure area associated with a different key. 46. The method of claim 38, in which the decryption key is executed, is by using stream encryption. 47. The method of claim 38, in which the decryption key is executed, is by using bounded stream encryption. 48. The method of claim 38, in which the decryption key is executed, is by using block encryption. 49. One or more sets of instructions therein that are readable by computers which, when executed by one or more computers, cause one or more of those computers to use the methods specified in Claim 38. 50. A system comprising a pathway for providing encrypted data in a secure region of the primary surface on the video card, a pathway for providing a secure region-associated key that can be used for decrypting the encrypted data, and a pathway relying on the key to decrypt the encrypted data in the secure region of the primary surface. 51. The process involves: preparing encrypted data in a secure region of the video card's primary surface (the secure region has a specific geometric shape); providing a key associated with the secure region that can be used to decrypt the encrypted data; informing the video card's decoder of the secure region's geometric shape; providing the key to the decoder; and decrypting the encrypted data in the secure region of the primary surface using the decoder. 52. The method of claim 51 in which the notification action is performed in response to the window displayed on the screen and in accordance with the safe area being dragged and dropped to a new position on the screen. 53. One or more sets of instructions therein that are readable by computers which, when executed by one or more computers, cause one or more of those computers to use the rights under claim 51. 54. The procedure consists of: preparing the encrypted data in a secure region of the primary surface on the video card; preparing a key associated with the secure region that can be used to decrypt the encrypted data; using the key to decrypt the encrypted data in the secure region of the primary surface; and detecting whether any data has been modified. 55. The method of claim 54, in which the detection action is performed, is prepared before the unencoded information is displayed on the screen. 56. The method of claim 54, in which the detection action is performed, relies on the authentication information associated with the encrypted data. 57. The method of claim 56, in which the authentication information consists of a security data format in which the predefined pixels must have a predefined value. 58. The method of claim 54, in which the detection action is performed, is by comparing the hash of the unencrypted data. 59. The method of claiming clause 54, which involves notification via a secure channel to the encryption component.