| Secure conditional access port interface -> Monitor Keywords |
|
|
  Secure conditional access port interfaceUSPTO Application #: 20060182279Title: Secure conditional access port interface Abstract: An apparatus and method thereof for providing a secure path for a digital signal in an intelligent transceiver such as a bi-directional set-top box. A digital signal (e.g., a broadcast signal or a signal received via a cable modem) is received by the intelligent transceiver at a front-end device (comprising, for example, a tuner). The digital signal is descrambled (if it is scrambled) and encrypted (if it is not encrypted) by a first functional block (e.g., an interface card or point of deployment) coupled to the front-end device. Coupled to the front-end device via the first functional block is a second functional block for processing (e.g., decoding) audio and/or visual content within the digital signal. Integrated into the second functional block is a decryption engine for decrypting encrypted signals. Signals from the front-end device are received via the first functional block by the decryption engine integral to the second functional block. There are no points between the first functional block and the decryption engine and between the decryption engine and the second functional block at which a descrambled and decrypted signal can be intercepted, thus providing a secure interface between the front-end device and the second functional block. (end of abstract) Agent: Wagner, Murabito & Hao LLP - San Jose, CA, US Inventors: Jun Maruo, Atsushi Kagami USPTO Applicaton #: 20060182279 - Class: 380210000 (USPTO) Related Patent Categories: Cryptography, Video Cryptography, Video Electric Signal Modification (e.g., Scrambling) The Patent Description & Claims data below is from USPTO Patent Application 20060182279. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This is a continuation of U.S. patent application Ser. No. 09/538,568 filed March 29, 2000. BACKGROUND OF THE INVENTION [0002] Digital broadcast systems include direct broadcast digital satellite systems, interactive World Wide Web ("Web") access systems, and digital cable systems. Digital broadcasting provides a number of advantages to subscribers, such as variety and flexibility of programming, useful and comprehensive support services (such as detailed electronic programming guides), and superior audio and video quality. [0003] The Conditional Access (CA) function of a digital broadcast system allows selective access, for a fee, to premium services such as pay-per-view movies and events. The producers of the movies, events, etc., require that access to the premium services be controlled in order to protect their commercial interests as well as to enforce copyrights and protect copyright ownership. The digital broadcast system operators (also referred to as Multiple System Operators, MSOs) also have a commercial interest in limiting access to these premium services to authorized users only. [0004] Subscribers receive digital broadcasts (including satellite, cable and Web broadcasts) via set-top boxes or other similar consumer electronic equipment located in the subscriber's home. With a bi-directional set-top box, in addition to receiving broadcasts, a subscriber can transmit messages to the MSO. Using the bi-directional set-top box (generally, a "transceiver" or "intelligent transceiver"), the subscriber selects a premium service, and the subscriber's selection as well as information needed for billing purposes is transmitted to the MSO. In a common implementation, a "smart card" stores the information needed for billing, and on a periodic basis (perhaps once per month) an automatic connection is made between the transceiver and the MSO so that the billing information can be transmitted to the MSO. [0005] Digital broadcast content is vulnerable to unauthorized use and duplication ("pirating") while it is being broadcast, or after it has been received and is being processed. For example, during broadcast, the signal could be intercepted and displayed (or duplicated and rebroadcast) using a transceiver not provided by the MSO. On the other hand, even when a transceiver provided by the MSO is used, the signal could be diverted within the transceiver so that the smart card is bypassed. In either case, copyrights are circumvented. In addition, the MSO is unaware of the unauthorized use and so does not have the information needed to collect the fees it is owed. [0006] To prevent unauthorized use, MSOs typically broadcast a scrambled signal. The signal is descrambled in the transceiver using a key provided by the MSO in the smart card. Once descrambled, the signal is encrypted in the transceiver. However, even when such security measures are employed in an attempt to prevent pirating, sophisticated methods are available to circumvent them. [0007] Prior Art FIG. 1 is a block diagram showing some of the elements in one embodiment of a prior art transceiver (e.g., a set-top box) (for clarity, not all of the elements of the set-top box are shown). Front-end unit 20 of the set-top box comprises a tuner (not shown), as well as other devices known in the art, for receiving a digital broadcast signal 90. Coupled to front-end unit 20 is point of deployment (POD) 10. POD 10 typically is adapted to receive a smart card (not shown) that, as described above, can be used to provide billing information to the MSO. The smart card also typically contains a key provided by the MSO that is used to descramble digital broadcast signal 90. POD 10 includes a descrambling/encryption unit 40 that uses the key provided by the MSO to descramble broadcast signal 90 (if the signal is scrambled). Descrambling/ encryption unit 40 also encrypts the signal (if the signal is not encrypted). It is appreciated that, in other prior art embodiments, descrambling/encryption unit 40 may consist of separate elements, one for descrambling and one for encrypting. [0008] Front-end unit 20 also includes decryption unit 50 for decrypting an encrypted broadcast signal before the signal is sent to audio/visual (A/V) decoder 30. A/V decoder 30 is used for demultiplexing the signal and for decoding, for example, MPEG (Moving Picture Experts Group) video signals and/or Dolby AC3 audio signals. [0009] Thus, in this prior art embodiment, digital broadcast signal 90 is received by the set-top box at front-end unit 20 and forwarded to POD 10. Broadcast signal 90 is descrambled by descrambling/encryption unit 40. Once descrambled, broadcast signal 90 is encrypted to prevent unauthorized duplication. Further downstream in the set-top box, broadcast signal 90 is decrypted using decryption unit 50 so that it can be decoded (e.g., MPEG or AC3 decoding) in AN decoder 30, and subsequently processed so that it can be viewed and/or listened to by an authorized subscriber. [0010] A problem with this prior art embodiment is that, between decryption unit 50 and AN decoder 30, broadcast signal 90 is transmitted in the clear at point 12 (that is, it is not scrambled nor is it encrypted at this point). Thus, at point 12, broadcast signal 90 can be intercepted and duplicated. As a digital signal, it is possible to make near perfect copies which can be readily distributed to unauthorized parties (e.g., rebroadcast via the Internet, copied onto a compact disk, etc.). While the MSO may receive payment for a one-time use, subsequent use by unauthorized users is made without proper compensation to the MSO or the copyright owners. [0011] Prior Art FIG. 2 illustrates some of the elements in another embodiment of a prior art set-top box (for clarity, not all of the elements are shown). Front-end unit 120, descrambling/encryption unit 140, POD 110, decryption unit 150, and A/V decoder 130 each function in a manner as described above in conjunction with FIG. 1. In this embodiment, decryption unit 150 is moved out of front-end unit 120 and closer to AN decoder 130. Even so, there still remains a point 14 at which broadcast signal 190 is transmitted in the clear and can be intercepted by an unauthorized user. [0012] Thus, the prior art is problematic because the descrambled and decrypted signal that is output from the decryption unit may be intercepted and pirated by an unauthorized user between the front-end device and the functional block (e.g., the A/V decoder). SUMMARY OF THE INVENTION [0013] Accordingly, what is needed is an apparatus and/or method that can prevent pirating of a descrambled and decrypted digital signal between a front-end device and a subsequent functional block (e.g., an audio/video decoding block). What is also needed is an apparatus and/or method that can address the above need and that can be implemented in a transceiver (e.g., a set-top box) used in a digital broadcast system. [0014] The present invention includes an apparatus and method thereof that satisfy the above needs. These and other advantages of the present invention not specifically mentioned above will become clear within discussions of the present invention presented herein. [0015] The present invention pertains to an apparatus and method thereof for providing a secure path for a digital signal in, for example, an intelligent transceiver such as a bi-directional set-top box. In the present embodiment, the present invention comprises an integrated circuit device with a functional block and a decryption engine integrated therein. The integrated circuit device (specifically, the decryption engine) receives an encrypted digital signal. The decryption engine is configured to decrypt the encrypted digital signal and to supply the decrypted digital signal to the functional block. There is not a point between the decryption engine and the functional block at which the digital signal is in the clear (e.g., descrambled and decrypted) and is externally accessible, thereby providing a physically secure interface between the integrated circuit device and the functional block. [0016] In one embodiment, a digital signal is received by an intelligent transceiver at a front-end device (comprising, for example, a tuner). The digital signal is descrambled (if it is scrambled) and encrypted (if it is not encrypted) by a first functional block (e.g., an interface card or point of deployment) coupled to the front-end device. Coupled to the front-end device via the first functional block is a second functional block used for processing (e.g., decoding) audio and/or visual (A/V) content within the digital signal. Integrated into the second functional block is a decryption engine used for decrypting encrypted signals. Digital signals from the front-end device are received via the interface card (or point of deployment) by the decryption engine integral to the A/V decode block. There are no points between the interface card (point of deployment) and the decryption engine nor between the decryption engine and the A/V decode block at which a descrambled and decrypted signal can be intercepted, thus providing a secure interface between the front-end device and the A/V decode block. [0017] In one embodiment, the digital signal is an audio/visual media signal delivered to the intelligent transceiver using, for example, a terrestrial line (e.g., a cable system), the World Wide Web (e.g., a connection to the Internet), or a wireless transmission (e.g., a satellite broadcast). [0018] In one embodiment, the encrypted signal is encrypted using an encryption routine compliant with the Data Encryption Standard Electronic Code Book (DES ECB). BRIEF DESCRIPTION OF THE DRAWINGS [0019] Embodiments of the present invention are illustrated by way of example and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: [0020] FIG. 1 shows a block diagram showing one embodiment of a prior art set-top box according to the conventional art. Continue reading... Full patent description for Secure conditional access port interface Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Secure conditional access port interface patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Secure conditional access port interface or other areas of interest. ### Previous Patent Application: Video stream display and protection method and device Next Patent Application: Method and apparatus for providing bootstrapping procedures in a communication network Industry Class: Cryptography ### FreshPatents.com Support Thank you for viewing the Secure conditional access port interface patent info. IP-related news and info Results in 1.17363 seconds Other interesting Feshpatents.com categories: Daimler Chrysler , DirecTV , Exxonmobil Chemical Company , Goodyear , Intel , Kyocera Wireless , |
||
