Title of Invention

"AN AUDIO/VIDEO (AV) STREAM PROCESSING SYSTEMAND METHOD THEREOF"

Abstract

An AV stream processing system includes an AV stream input unit which receives an AV stream having an AV content information field including first copy control information, and an AV content field including second copy control information, a determination unit which extracts the first and second copy control information from the received AV stream and determines whether the first copy control information has been modified, and an AV stream decryption unit which processes the received AV stream according to predetermined criteria, when the first copy control information has been modified.

Full Text

Description AUDIO/VIDEO STREAM PROCESSING SYSTEM AND METHOD FOR DATA COPY PROTECTION Technical Field Systems, apparatuses, and methods consistent with the present invention relate to protecting data, and more particularly, to protecting against unauthorized copying of audio/ video (AV) contents by using copy control information (CCI) incUded in an AV stream. Background Art Generally, an AV stream incbdes content and copy control information indicating the status of a copy control of the content. That is, the copy control information indicates whether an AV stream processing system, for example, a recorder im-plemenled by hardware or software, has an authorization to copy the content included in the AV stream received from a transmitting medium. The recorder, for example, decrypts the content based on a value of the copy control information. The copy control information may be indicated with bits, as predetermined within the AV stream, for example, with a 2-bit code. Four types of modes capable of constituting the copy control information are listed in Table 1 as follows .( Table Remove) [4] FIG. 1 illistratcs a schematic structure of an AV stream 100. The AV stream 100 comprises a content field whidi includes contents and an information field which incbdes information on the contents. The information field comprises a region I 10 lor copy control information, which is used to control a copying operation of an AV apparatus, and information on a variety of contents contained in the AV stream 100. The content field is divided into n sub-unit regions, that is, 'Content_unit_l,' 'Content_unit_2,' ... 'Content_unit_n.' [5] The region 110 inclidcd in the information field for copy control information ('first copy control information') is divided into regions corresponding to the number of the sub-units. Eadi of the divided regions comprises a copy control information value, sudi as 00, 01, 10 and 11, and location information of a corresponding one of the sub units. The location information may comprise physical or logical addresses for the corresponding sub-unit, or time information relating to when the content in the sub-unit is played. FIG. I refers to the location information as 'unit_l_ptr,' 'unii....2_ptr,' ... 'unil_.n._ptr.' |6| A sub-unit may be divided into one or more regions. By way of example, a sub- unit included in the content field, that is, 'Content _unit .2' may be divided into three small regions of'Sub 2. I,1 'Sub_2__2 ' and ' Sub_2__3,' and cadi of the small regions may include a corresponding copy control information 130 thereto. | ""I The copy control information inclided in each sub-unil of the content field ('second copy control information') is used to generate a decryption key to decrypt the content, and thus, if il is modified, the contents cannot be decrypted. For example, the copy control information 130 of Sub_2_l is used to generate a decryption key to decrypt the content of Sub__2_ 1. However, the first copy control information 1 10 is used 10 control a copying operation, and thus, an unauthorized copying of (he contents becomes possible as a third party may change the first copy control information 110. •S| F-'IG. 2 shows a conventional AV stream data copy protection system to protect contents from being copied without authorization from an owner of the contents. The A V stream data copy protection system 200, which decrypts encrypted AV stream data, comprises an AV stream receiving unit 210, a control unit 220, a decryption key-generating unit 230, and a content interpreting unit 240. The AV stream receiving unit 210 receives AV stream data. The control unit 220 receives a control signal to control an operation of an AV apparatus, input from the outside. The control signal may comprise a command signal to play the content or a command signal to copy the content. Referring to FIG. 1, the control'unit 220 receives the first copy control information 110 transmitted from the AV stream receiving unit 210, and transmits a control signal corresponding to a vakic of the first copy control information 110 to the decryption generating unit 230 and the content interpreting unit 240. |l)I In detail, the AV stream receiving unit 210 receives AV stream data, and transmits to the control unit 220 the first copy control information 110 inckided in the AV stream data . The control unit 220 receives a control signal to control an operation of an AV apparatus from the outside. When the control signal is a command signal to copy content, the control unit 220 checks an encryption status of AV contents in the AV stream data received by the AV stream receiving unit 210, by referring to the first copy control information 110. 10| When a value of the first copy control information 1 10 is 'copy free,' there is no need to generate a decryption key, and thus, the control unit 220 allows the content interpreting unit 240 to transmit the AV stream data to an output device 250 as received by the AV stream receiving unit 210. When the value of the first copy control information 1 10 is 'no more copy or copy never,' 'copy free but encrypted,' or 'copy one generation,' data is required to be decrypted. Accordingly, the decryption key generating unit 230 receives the first copy control information 1 10 from the control uiiii 220, generates a decryption key by using the second copy control information I 30 and other information from the AV stream receiving unit 2 10, and transmits the decryption key to the conteni interpreting unit 240. The content interpreting unit 240 decrypts a content field of the AV stream data received hy the AV stream receiving unit 210, hy us ing the decryption key, and transmits decrypted AV content to an output device 250, such as a storage medium or a displaying apparatus. j 1 I | The conventional AV stream data copy protection system 200 uses the first copy control information 1 10 to check whether an AV apparatus has an authorization to copy the contents. However, the first copy control information I 10 may he easily modified to facilitate unauthorized copying of the contents. Therefore, for example, when 'no more copy or copy never' (I 1) or 'copy one generation' (10) is modified to 'copy free hut encrypted' (01), or when 'no more copy or copy never' (I I) is modified to 'copy one generation' (10), and such modified information is received by the AV stream receiving unit 210 of the conventional AV stream data copy protection system 200, the control unit 220 may falsely confirm that copying of an AV stream has been allowed. Accordingly, unauthorized copying of the contents may be accomplished. Disclosure of Invention | 121 Accordingly, it is an aspect of the present invention to provide an AV stream data processing system which prevents unauthorized processing of contents through, for example, modification of copy control information. i M | Another aspect of the present invention is to provide a method of protecting contents, ineLding determining \vhether copy control information has been modified and appropriately responding to the modification. I4| Additional aspects and/or advantages of the present invention will be set forth in part in the description whidi follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 15 To adrievc the above and/or other aspects of the present invention, there is provided an audio/video (AV) stream processing system comprising a receiving unit whidi receives an AV stream comprising a content information field and a content field, wherein the content information field comprises first copy control information, and the conteni field comprises second copy control information, a determination unit which determines whether the first and second copy control information are different, and a decryption unit for processing the AV stream. "'I The determination unit may determine whether copy control mode information of the lirsi and second copy control information are different. i i 7I The decryption unit may stop decrypting content of the AV stream when the first and second copy control information arc different . I 181 The decryption unit may slop generating a decryption key lor decrypting content of the AV stream when the first and second copy control information are different. M ^1 The decryption unit may process content of the AV stream according to one of ihc lirsl and second copy control information having a higher priority over (he other, when Ihc tirst and second copy control information are different. The determining unit may establish priority between the first and second copy control information. The second copy control information may have priority over the first copy control information when the first and second copy control information are different. The first copy control information may have priority over the second copy control information when the first and second copy control information are different. The one of the first and second copy control information may have higher priority over the other when the one provides enhanced copy control protection over the other. [20| Each of the first and second copy control information may comprise a copy control mode of content of the AV stream, and the copy control mode may comprise a first mode in wftdi the content is encrypted and copying thereof is absokitcly prchbitcd, a second mode in when the content is encrypted and one time copying thereof is allowed, wherein the second mode being dianged to the first mode after the one time copying, a third mode in which the content is encrypted and unrestricted or unlimited copying thereof is allowed, and a fourth mode in whch the content is not encrypted and unrestricted or unlimited copying thereof is allowed. 1211 The decryption unit may comprise a key generating unit which generates a decryption key for decrypting the content, a content interpreting unit wrich decrypts (he content using the decryption key, and a control unit which controls the key generating unit and the content interpreting unit to stop generating the decryplion key or slop decrypting the content when the first and second copy control information are different, and when the first and second copy control information are the same, controls the key generating unit and the content interpreting unit according to the copy control mode. When the first and second copy control information are different, or the copy control mode corresponds to the first mode, generating of the decryption key or decrypting of the content may be stopped to prevent unauthorized copying of the content. The key generating unit may generate the decryption key using information comprising the second copy control information. The control unit may control the key generating unit to generate the decryption key to decrypt the content in response to the copy control mode being one of the second and third mode, and control the conicnl interpreting unil to output the content, as is, in response to the copy control mode being ihc fourth mode. !22j The system may further comprise a storage unit which stores the decrypted content or the as is content. \ -\i | The system may further comprise a displaying unit which displays the decrypted content or the as is content. 12-1-1 The determining unil may comprise a storage unit which stores the first copy control information, and a comparator unit which compares the copy control mode of the first copy control information with that of the second copy control information. [251 The decryption unit may comprise a control unit which outputs a signal cor- responding to the copy control mode when the first and second copy control information arc the same, and generates a stop signal when the first and second copy control information are different or the signal corresponds to the first mode, wherein the control unit outputs the stop signal to the key generating unit when the AV stream is not being played and outputs the stop signal to the content interpreting unit when the A V stream is being played, a key generating unit which generates a decryption key for decrypting the content in response to the signal corresponding to one of the second and third mode, and stops generating the decryption key in response to the stop signal, and a content interpreting unit which decrypts the content using the decryption key, outputs the content, as is, in response to the signal corresponding to the fourth mode, and stops decrypting the content in response to the stop signal. 1261 The decryption unit may stop processing the AV content when the first and second copy control information are different. [27 j The decryption unit may process the AV stream using one of the first and second copy control information providing enhanced copy protection over the other, when the first and second copy control information are different. (281 To achieve the above and/or other aspects of the present invention, there is provided another audio/video (AV) stream processing system comprising means for receiving an AV stream comprising a content information field and a content field, means for processing the AV stream, and means for dctcrmin ing whether copy control information of the content information field has been modified. 291 The processing means may stop processing the AV stream when the copy control information has been modified. The processing means may process the AV stream using one of the copy control information of the content information field and copy control information of the content field having a higher priority over I he other, vvhcn the copy control information of the content information field has been modified. To achieve the above and/or other aspects of the present invention, there is provided still another audio/video (AV) stream processing system comprising means for receiving an AV stream comprising a content information field and a content field, wherein (he content information field comprises first copy control information, and the content field comprises second copy control information, means for processing the AV stream, and means for determin ing whether the first and second copy control information arc different. To achieve the above and/or other aspects of the present invention, there is provided yet another audio/video (AV) stream processing system comprising a receiving unit whidi receives an AV stream comprising a content information field and a content field, wherein the content information field comprises first copy control information, and the content field comprises second copy control information, a determination unit which compares the first copy control information with the second copy control information, and a decryption unit whch stops processing the AV stream or processes the A V stream using one of the first and second copy control information having a higher priority over the other, when the first and second copy control information are different. 321 To achieve the above and/or other aspects of the present invention, there is provided still yet another audio/video (AV) stream processing system comprising a receiving unit whidi receivs an AV stream comprising a content information field and a content field, wherein the content information field comprises first copy control information, and the content field comprises second copy control information, a determination unit which determines whether the first copy control information has been modified when compared to the second copy control information, and a decryption unit for processing the AV stream. 331 To achieve the above and/or other aspects of the present invention, there is provided an apparatus for copy control for use in an audio/video (AV) stream processing system which processes an AV stream comprising a content information field and a content field, the apparatus comprising an extracting component which extracts copy control information of the content information field and copy control information of the content field from the AV stream, and a determining component which determines whether the copy control information of the content information field and the copy control information of the content field are different. i U| The determining component may determine whether copy control mode in- lormalion, corresponding lo the content of the AV stream, of the first and second copy control information are different so as lo prevent unauthorized processing of (he AV Mrcam. 1 ^| To achieve the above and/or other aspects of the present invention, ihere is provided another apparatus for copy control for use in an audio/video (AV) stream processing system which processes an AV stream, the apparatus comprising an extracting component which extracts copy control information from a content information field of the AV stream, and a determining component which determines whether the copy control information has been modified. I i of the content information field has been modified when compared to copy control information of a content field of the AV stream, so as to prevent unauthorized processing of the AV stream. 1371 To achieve the above and/or other aspects of the present invention, there is provided still another apparatus for copy control for use in an audio/video (AV) stream processing system which processes an AV stream comprising a content information field and a content field, the apparatus comprising an extracting component which extracts copy control information of the content information field and copy control information of the content field from the AV stream, and a comparing component which compares the copy control information of the content information field and the copy control information of the content field to determine whether the copy control information of the content information field and the copy control information of the content field are different. ->iS I To achieve the above and/or other aspects of the present invention, there is provided yet another apparatus for copy control for use in an audio/video (AV) stream processing system which processes an AV stream comprising a content information field and a content field, the apparatus comprising an extracting component which extracts copy control information of the content information field and copy control information of the content field from the AV stream, and a determining component which establishes priority between the copy control information of the content in-lonnation field and the copy control information of the content field, when the copy control information of the content information field and the copy control information of (he content field arc different. ,W| The determining component may establish one of the copy control information of ihe content information field and the copy control information of the content Held providing enhanced copy protection over the other as information for processing the AV stream, when the copy control information of the content information field and the copy control information of the content field are different. The determining component may establish the copy control information of (he content information field as information for processing the AV stream, when the copy control information of the content information field and the copy control information of the content field are different. The determining component may establish the copy control information of the content field as information for processing the AV stream, when the copy control information of the content information field and the copy control information of the content field are different. To achieve the above and/or other aspects of the present invention, there is provided an AV stream processing method comprising receiving an AV stream comprising a content information field and a content field, wherein the content information field comprises first copy control information, and the content field comprises second copy control information, determining whether the first and second copy control information are different, and processing the AV stream based on the determination. 1411 The determining of whether the first and second copy control information are different may comprise determining whether copy control mode information of the first and second copy control information are different. The processing of the AV stream may comprise processing the AV stream according to the copy control mode information when the first and second copy control information are the same. [421 The processing of the AV stream may comprise terminating decrypting of content of ihc AV stream when the first and second copy control information are different. 1431 The processing of the AV stream may comprise terminating generating of a decryption key for decrypting content of the AV stream when the first and second copy control information are different. 1441 The processing of the AV stream may comprise processing content of the AV stream using one of the first and second copy control information providing enhanced copy protection over the other, when the first and second copy control information arc different. |4S | When ihc first and second copy control information are different, the processing of the AV stream may comprise one of terminating processing of the AV stream, and processing the A V stream using one of the first and second copy control information having a higher priority over the other. When the first and second copy conlrol in-lormation arc different, the processing of the AV stream may comprise processing content ol the AV stream using the second copy conlrol information. When the first and second copy control information are different, the processing of the AV stream may comprise processing content of the AV stream using the first copy control in-lormation. 1461 When the first and second copy control information are different, the processing of the AV stream may comprise terminating decrypting of content of (he AV stream when the A V stream is being played, or terminating generating of a decryption key lor decrypting content of the AV stream when the AV stream is not being played. 1471 flic method may further comprise displaying a message indicating (hat processing of the AV stream is prohibited. The method may further comprise establishing the second copy control information as having priority over the first copy conlrol information when the first and second copy control information are different, wherein the processing of the AV stream comprises processing content of the AV stream using the second copy control information. The method may further comprise establishing the first copy control information as having priority over the second copy control information when the first and second copy control information are different, wherein the processing of the AV stream comprises processing content of the AV stream using the first copy control information. [481 To achieve the above and/or other aspects of the present invention, there is provided another AV stream processing method comprising receiving an AV stream comprising a content information field and a content field , determining whether copy conlrol information of the content information field has been modified, and processing the AV stream based on the determination. [491 The processing of the AV stream may comprise terminating processing of the AV stream when the copy control information has been modified. 1501 The processing of the AV stream may comprise processing the AV stream using one of the copy control information of the content information field and copy control information of the content field having a higher priority over the other, when the copy control information of the content information field has been modified. 15 I | To achieve the above and/or other aspects of the presenl invenlion, there is provided still another AV stream processing method comprising receiving an AV stream comprising a content information field and a contcnl field, \vhcrcin the content information field comprises first copy control information, and the content field comprises second copy control information, determining whether the first and second copy control information arc different so as to prevent unauthorized processing ol the .A V slream, and processing the AV stream based on the determination. [521 To achieve the above and/or other aspects of the present invention, ihcrc is provided yet another AV stream processing method comprising receiving an AV stream comprising a content information field and a content field, wherein Ihe content information field comprises first copy control information, and the content field comprises second copy control information, comparing the first copy control information with the second copy control information, and when the first and second copy control information are different, performing one of terminating processing of the AV stream and processing the AV stream using one of the first and second copy control information having a higher priority over the other. 1531 To achieve the above and/or olhcr aspccls of the present invention, there is provided still yet another AV stream processing method comprising receiving an AV stream comprising a content information field and a content field, wherein the content information field comprises first copy control information, and the content field comprises second copy control information , determining whether the first copy control information has been modified when compared to the second copy control information, and processing the AV stream based on the determination. 1541 To achieve (he above and/or other aspects of the present invcnlion, there is provided a method for copy control in processing an audio/video (AV) slream comprising a content information field and a content field, the method comprising extracting copy control information of the content information field and copy control information of the conlenl field from the AV slream, and determining whether the copy control information of the content information field and the copy control information of the content field are different. [551 The determining may comprise determining whether copy control mode in- formation, corresponding to (he conlenl of the AV slream, of the firsl and second copy control information are different so as to prevent unauthorized processing of the AV stream. 1561 To achieve the above and/or other aspects of Ihe present invention, there is provided another method for copy control in processing an audio/video (AV) slream, the method comprising extracting copy control information from a content information field of the A V stream, and determining whether the control information has been modified. The determining may comprise determining whether the copy control informal ion ol the content information field has been modified when compared to copy control in-lormuiion ol a content field ol the AV stream, so as to prevent unaulhori/.ed processing of the A V stream. To achieve (he above and/or other aspects of the present invention, there is provided still another method for copy control in processing an audio/video (AV) stream comprising a content information field and a content field, the method comprising extracting copy control information of the content information field and copy control information of the content field from the AV stream, and comparing the copy control information of the content information field and the copy control information of (he content field to determine whether the copy control information of the content information field and the copy control information of the content field are different. 15l) | To achieve the above and/or other aspects of the present invention, there is provided yet another method for copy control in processing an audio/video (AV) stream comprising a content information field and a content field, the method comprising comparing copy control information of the content information field with copy control information of the content field, and establishing priority between the copy control information of the content information field and the copy control information of the content field, when the copy control information of the content information Held and Ihe copy control information of the content field are different. 1601 The establishing may comprise establishing one of the copy control information of the content information field and the copy control information of the content field providing enhanced copy protection over the other, as information for processing the AV stream when the copy control information of the content information field and the copy control information of the content field are different. The establishing may comprise establishing the copy control information of the content information field as information for processing the A V stream, when the copy control information of the content information field and the copy control information of the content field are different. The estabEshing may comprise establishing the copy control information of the content field as information for processing the AV stream, when the copy control information of the content information field and the copy control information of the content field are different. Brief Description of Drawings [ 61 | These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of Ihe aspects of the present invention, taken in conjunction with the accompanying drawings of whidi: FIG. I is a schematic diagram illustrating a configuration of an A V stream; FIG. 2 is a block diagram illustrating a configuration of a conventional A V stream processing system; 1641 FIG. 3 is a block diagram illustrating an AV stream processing system for data copy protection according to an embodiment of the present invention; 165 FIG. 4 is a block diagram illustrating an AV stream processing system for data copy protection according to another embodiment of the present invention; 1661 FICi. 5 is a block diagram ilLislrating an AV stream processing system for data copy protection according to still another embodiment of the present invention; 1671 FIG. 6 is a How chart illistrating a method of processing an AV stream for copy protcclion according to an embodiment of the present invention; and 16S | FIGS. 7 and 8 are How charts illustrating AV stream data copy control methods according to other embodiments of the present invention, when first copy control information and second copy control information are not identical. Best Mode for Carrying out the Invention Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to Skc elements throughout. The embodiments arc described below in order to explain the present invention by referring to the figures. And, for easy description, while embodiments of the present invention will be herein described with reference to four types of copy control information statuses and 2-bit copy control information codes corresponding to the respective copy control information states indicated in Table 1 , it is understood that the present invention is not limited thereto. The copy control information statuses according to an exemplary embodiment of the present invention may comprise a part of the indicated four types or more than the four types. The copy control information codes are also not limited to the 2-bit information and may be represented in any form which can indicate the copy control information status. Antl additionally, the second copy control information may refer to (he copy control information 130 incbded in each of the sub units included in the content field shown in FIG. 1, or otherwise refer to the copy control information to represent each of the sub units. 0| FIG. 3 shows an AV stream processing system for data copy protection according to an embodiment of the present invention. The AV stream processing system 300 comprises an AV stream receiving unit 310, a modification determining unit 320 and a decryption unit 330. The AV stream receiving unit 310 receives an AV stream and transmits the received AV stream to the modification determining unit 320. Referring to HCiS. I and 3, the modification determining unit 320 compares first and second copy control information inckjded in the AV stream. When it is determined that a vaLic of the first copy control information is different than that of the second copy control information , the AV stream processing system 300 determines whether to decrypt the AV stream according to predetermined criteria. 171 | When it is determined that a value of the first copy control information is identical to a valie of the second copy control information, the decryption unit 330 conducts a decryption operation corresponding to the value of the copy control information. At this time, there is no need to decrypt the AV stream \vhen a valie of the copy control information corresponds to 'copy free,' and thus, the decryption unit 330 transmits the AV stream (as received by the AV stream receiving unit 3 10) to, for example, an AV stream output device 340. When the valie of the copy control information corresponds to 'no more copy or copy never,' 'copy free but encrypted', or 'copy one generation,' the decryption unit 330 generates a decryption key by using the second copy control information from the modification determining unit 320 and other information, decrypts AV content of the AV stream with the decryption key, and transmits the decrypted AV content to, for example, the AV stream output device 340. The other information used to generate the decryption key may comprise at least one of a seed valie randomly generated to generate the decryption key, a valie of common key or secret key inherent within an AV apparatus, and a valie of common key or secret key corresponding to the storage media for AV content. According to various aspects, the AV stream output device 340 may comprise an electrical or an optical recording medium, a storage medium on which the AV stream as read may be recorded, or a displaying apparatus on which the AV stream as read may be displayed. According to other aspects, the decryption unit 330 may transmit the decrypted AV content through a wire or a wireless transmission medium, in lieu of the output device 340 above. 1721 FIG. 4 shows an AV stream processing system for data copy protection according to another embodiment of the present invention. The AV stream processing unit 400 comprises an AV stream receiving unit 410 which receives an AV stream, a modification determining unit 420 when determines whether copy control information inclidcd in the AV stream has been modified, and a control unit 430 which determines whether to decrypt the AV stream according to the determination result of the mod- ificalion determining unit 420 and transmits a command signal for decryption, corresponding to a vatic of the copy control information, to a decryption key generating unit 440. The AV stream processing unit 400 further comprises the decryption key generating unit 440 which receives a decryption command from the control unit 430 and generates a decryption key by using second copy control information received from the modification determining unit 420 and other information used to generate the decryption key, and a content interpreting unit 450 which decrypts AV content of the AV stream by using the decryption key transmitted form the decryption key generating unit 440 and transmits the decrypted AV content to one output device 460 of a variety ol output devices described above, known in the art . 1731 By way of an example, an operation of the AV stream processing unit 400 is as follows. The AV stream receiving unit 410 receives an AV stream, transmits the AV stream to the modification determining unit 420, and transmits contents of the AV stream to the content interpreting unit 450. At this time, the control unit 430 receives a control signal to control an operation of an AV apparatus from the outside. For example, the control signal may be a signal to allow the AV apparatus to play the co ntcnts of the AV stream, or a signal to allow the AV apparatus to copy the contents to a predetermined storage space. 1741 The modification determining unit 420 extracts first and second copy control in- formation of the AV stream to determine whether they have the same vabc. When the first and second copy control information are nol identical, the modification determining unit 420 determines that the first copy control information has been modified and transmits a signal to the control unit 430 indicating that the copy control information has been modified. In response, the control unit 430 transmits a command signal to the content interpreting unit 450 to stop decrypting the contents, thereby preventing unauthorized copying of the contents. At this time, the control unit 430 transmits a command signal to the decryption key generating unit 440 to stop generating the decryption key, thereby preventing the decryption key itself from being generated. (751 According to other aspects, when the first and second copy control information are different, or when it is determined that one of the first and second copy control information has been modified, the modification determining unit 420 may establish a priority between the first and second copy control information. In this case, the control unit 430 determines whether to decrypt the AV stream according to the vatic of the copy control information having a higher priority over the other copy control in- lormuiion. t;or example, when ihe first and second copy control information arc not identical, for example, have values ' 10' and '11,' (Sec Table I above; respectively, the copy control information having a higher copy protection valic may be used, that is, a higher copy protection valie ' II' may be used over a lower copy protection value ' 1 ()' of the other copy control information when the determining unit 420 establishes that the second copy control information has priority over the first copy control information, 'fable I shows an example of the priori tization of copy protection vahes, ranging from '00', having the lowest copy protection value, to 'I I', having the highest copy protection valic. A higher copy protection vatic provides enhanced copy protection over a lower copy protection valie. 176) When it is determined by the modification determining unit 420 that the first and second copy control information have the same vakie or that, for example, the first copy control information has not been modified, the modification determining unit 420 transmits Ihe valie of the first copy control information to the control unit 430 and transmits (he second copy control information and other information used to generate the decryption key to the decryption key generating unit 440. The other information may comprise at least one of a seed valic randomly generated to generate the decryption key, a valie of common key or secret key inherent within an AV apparatus, and a value of common key or secret key corresponding to the storage media for AV content. The control unit 430 checks the valic of the first copy control information as received. When Ihe valie of the first copy control information corresponds to 'copy free,' there is no need to decrypt the AV content of the AV stream, and therefore, the control unit 430 sends a command to the content interpreting unit 450 to transmit the A V content, as received, to an output device 460. When the valie of the first copy control information corresponds to 'no more copy or copy never,' 'copy free but encrypted,' or 'copy one generation,' the control unit 430 transmits the first copy control information to the decryption key generating unit 440, thereby authorizing the unit 440 to generate the decryption key. At this lime, the decryption key generating unit 440 generates the decryption key by using the second copy control information and the other information received from the modification determining unit 420, and transmits it to the content interpreting unit 450. [ 771 The content interpreting unit 450 receives a command from the control unit 430 to execute a decryption of the AV content received from the AV stream receiving unii 410, and decrypts the received AV content by using the decryption key transmitted from the decryption key generating unit 440. The content interpreting unit 450 outputs decrypted A V content to the output device 460. For example , the output device 460 may comprise an electrical or optical recording medium, a storage medium on which the AV stream as read may be recorded, or a displaying apparatus on which the AV stream as read may he displayed. According to other aspects , the content interpreting unit 450 may transmit the decrypted AV content through a wire or a wireless transmission medium in icu of the output device 460 above. FIG. 5 shows an AV stream processing system for data copy protection according 10 still another embodiment of the present invention. The AV stream processing system 500 comprises an AV stream receiving unit 5 10, a control unit 520, a decryption key generating unit 530, a modification determining unit 550, and a content interpreting unit 540. The modification determining unit 550 comprises a copy conlrol in formal ion (CCI) storage unit 552 and a CCI comparator unit 554. The AV stream receiving unit 510 receives an AV stream and transmits AV contents included in the AV stream to the content interpreting unit 540. The conlrol unit 520 receives first copy control information inclided in the AV stream transmitted from the AV stream receiving unit 510, transmits a command signal corresponding to the first copy control information to the decryption key generation key 530 and the content interpreting unit 540, and transmit s the first copy control information received from the AV stream receiving unit 510 to the CCI storage unit 552. The decryption key generating unit 530 receives second copy control information included in the AV stream, from the AV stream receiving unit 510, and other information used to generate a decryption key, generates the decryption key \vhen an authorization to generate the same is granted from the control unit 520, and transmits the generated decryption key to ihe content interpreting unit 540. The modification determining unit 550 determines whether the copy control information has been modified. The CCI storage unit 552 receives and stores the first copy control information transmitted from Ihe conlrol unil 520. The CCI comparator unit 554 receives the second copy control information transmitted from Ihe decryption key generating unit 530 and compares a valie thereof with a value of the first copy control information in the CCI storage unil 552, so as to determine whether the first copy control information has been modified. The content interpreting unit 540 receives a command to decrypt the AV content of the AV stream from the control unit 520 and a decryption key from the decryption key generating unit 530, and decrypts the AV content received from the AV stream receiving unit 5 10. The content interpreting unit 540 transmits the decrypted AV content to an output device 560. ;X The AV stream receiving unit 510 receives an AV stream and transmits first copy control information inckided in the AV stream to the control unit 520. The AV stream receiving unit 510 also transmits second copy control information included in the AV stream to (he decryption key generating unit 530 and AV contents ol the AV stream to ihe content interpreting unit 540. The control unit 520 receives a control signal to control an operation of an AV apparatus, input from the outside. For example, the control signal may be a signal to allow the AV apparatus to play the AV contents of the A V stream or a signal to copy '.he AV contents to a predetermined storage space. IS I When the first copy control information has a vabe corresponding to 'copy free,' there is no need to decrypt the AV content, and therefore, the control unit 520 sends a command to the content interpreting unit 540 to transmit the as received AV content to an output device 560. When the first copy control information has a vatic corresponding to 'no more copy or copy never,' 'copy free but encrypted,' or 'copy one generation,' the control unit 520 transmits the first copy control information to the decryption key generating unit 530, thereby authorizing the unit 540 to generate a decryption key. At this time, the decryption key generating unit 530 generates the decryption key by us ing the second copy control information previously received from the AV stream receiving unit 510 and other information used to generate the decryption key . The decryption key generating unit 530 transmits the generated decryption key to the content interpreting unit 540. Other information may comprise at least one of a seed vabe randomly generated to generate the decryption key, a vaLic of common key or secret key inherent within an AV apparatus, a value of common key or secret key corresponding to the storage media for AV content, etc. 182 The CC1 comparator unit 554 receives the second copy control information transmitted from the decryption key generating unit 530, compares it with the vabe of the first copy control information stored in the CCI storage unit 552, determines whether the first copy control information has been modified, and transmits the determination result to the control unit 520. When the vabe of the first copy control information is different from the vabe of the second copy control information, it is determined that the first copy control information has been modified. In this case, the control unit 520 transmits a command to suspend decryption of the A V contents to the content interpreting unit 540, and accordingly, the content interpreting unit 540 does not decrypt the AV content already received, and , for example, the AV stream processing system 500 suspends playing of the AV content. According to another aspect, the control unit 520 may transmit a command signal lo suspend generation of a decryption key to the decryption key generating unit 530, to thereby stop the decryption key itself from being generated. N •> | According to still another aspect, when the first and second copy control in- formal ion arc different, the modification determining unit 550 establishes a priority between the first and second copy control information. In this case, (he control unit 520 determines whether to decrypt the AV stream according to a value of the copy control information having a higher priority over the other copy control information. |S4| When it is determined that the first and second copy control information have the identical value, (his determination result is transmitted to the control unit 520. The control unit 520 sends a command to the content interpreting unii 540 lo decrypi the A V content of the AV stream already received from the A V stream receiving unit 510. The content interpreting unit 540 receives a command from the control unit 520 to execute decryption of the AV content as already received from the AV stream receiving unit 510, and decrypts the received AV content by using the decryption key transmitted from the decryption key generating unit 530. The content interpreting unit 540 outputs the decrypted AV content to the output device 560. For example, the output device 560 may comprise an electrical or optical recording medium, a storage medium on which an AV stream as read can be recorded, or a displaying apparatus on whidi the A V stream as read may be displayed. According to other aspects, the content interpreting unit 540 may transmit the decrypted AV content through a wire or a wireless transmission medium in fieu of the output device 560 above. 1851 As described above, according to an aspect of the present invention, the CCI comparator unit 554 of the modification determining unit 550 compares the first copy control information with the second copy control information and transmits the comparison result to the control unit 520, and a command signal corresponding to the comparison result is transmitted to the content interpreting unit 540. According to another aspect, the CCI comparator unit 554 may directly transmit the command to the content interpreting unit 540. (S6| FIG. 6 shows a flow chart illustrating'an AV stream processing method for copy protection according to an embodiment of the present invention. As shown in FIG. 6, an AV stream is input and the input AV stream is temporarily stored in a temporary storage space, in operations 605 and 610, respectively. In operation 615, llrst copy control information and second copy control information incbdcd in the AV stream are extracted and compared with each other. When the first copy control information has a different valie from that of (he second copy control information, the method may proceed to operation 670 to be described in detail with reference to FIC1S. 1 and 8. 1871 When the vaLes of the first and second copy control information are of the same, a corresponding process is executed in operation 625. For example, when the values of the first and second copy control information are 'copy free,' that is, '00,' (here is no need to decrypt the AV contents of the AV stream. Thus, the AV stream is directly copied in operation 630. When the valies of the first and second copy control information are 'copy free but encrypted,' or 'copy one generation,' thai is, '01' or '10,' a dccryplion key is generated so as to decrypt the AV stream in operation 635. When the valies of the first and second copy control information are 'no more copy or copy never,' that is, 'I I,' it is checked whether the AV stream is currently being played in operation 640. When the AV stream is being played, decryption of the AV stream for copying the AV contents is not performed, in operation 645. When the AV stream is not being played, the decryption key for decryption of the contents is not generated , in operation 650 . In operation 655, a message indicating that the AV stream cannot be decrypted because copying thereof is prohibited, is provided through a displaying means known in the art (no t shown). 1881 FIGS. 7 and 8 are flow charts illistrating AV stream data copy control methods according to other embodiments of the present invention, when first copy control information and second copy control information arc not identical. FIG. 7 ilLstratcs that decryption of AV contents is not performed, unconditionally, and FIG. 8 illustrates that decryption of an A V stream is determined based on a valie of copy control information having a higher priority by establishing a priority between the first copy control information and the second copy control information. 1891 Referring to FIG. 7, when vaLes of the first and second copy control information are not the same, it is checked whether the AV stream subject to copying is being played in operation 705. When the AV stream is being played, this means that a decryption key has already been generated, and thus, a decryption process us ing the decryption key is not performed, in operation 710. When the AV stream is not being played, the decryption key is not generated, in operation 715. In operation 720, a message indicating that the AV stream cannot be decrypted because copying thereof is prohibited, is provided through a displaying means known in the art (not shown). Referring to FIG. 8, when the vabes of the first and second copy control information arc not identical, it is checked as to which copy control information is established to have a higher priority valie, and the copy control information having the higher priority vabe is set to 'Priority CCI_info.' According to an aspect, il is checked whether the first copy control information has priority in operation 750, and if.so. the lirsl copy control information is set to 'Priorily_CCI_inlb' in operation 754, and if not, the second copy control information is set to 'Priority^CCI info' in operation 754. I' I : When a valie of the 'Priority_CCl_info' is '00,' that is, 'copy free,1 an A V stream is not encrypted and free copying thereof is allowed. In this case, since there is no need to decrypt the AV content of the AV stream, the AV stream is directly copied in operation 758. When the value of the 'Priority_CCI_info' is '01' or '10,' that is, 'copy free hut encrypted' or 'copy one generation,' a decryption key is generated to decrypt the A V stream in operation 760. At iris time, the value of '10' means that only one time copying is available and copying of the contents is prohibited there after, and therefore, the valie of the concerned copy control information is changed to ' I I' after the copying. When the value of Priority_CCI_info' is '1 1,' that is, 'no more copy or copy never,1 decryption of the AV content is absolitely prohibited. In this case, it is checked whether the AV stream is currently being played in operation 762. Were the A V stream is being played, this may mean that the decryption key has already been generated, and thus, a decryption process using the decryption key is not performed, in operation 764. When the AV stream is not being played, the decryption key is not generated, in operation 766. In operation 768, a message indicating that the AV stream cannot he decrypted because copying thereof is prohibited is provided through a displaying means known in the art (not shown). 1921 It is further understood that while illistrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above, the present invention is not required to overcome the disadvantages described above, and illistrative, non-limiting embodiments of the present invention may not overcome any of the problems described above. | ().i | Although a few embodiments of the present invention have been shown and described, il will be appreciated by those skilled in the art lhat changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents. Industrial Applicability 1041 Means and methods for unauthorized copy protection of contents according to the present invention, as described above, and obvious from the description provided above, may be applied to a variety of systems and apparatuses which may be implemented by hardware and/or software, including digital and electronic household appliances and other electronic goods used to store and/or play an AV stream which muv or may not have copy control information. It is understood that the AV stream may refer to data for audio and/or video recording, and unaulhon/ed processing may ivlcr lo unauihori/.cd accessing, displaying, copying, or a combination thereof. It is also understood that a system which uses the present invention also includes permanent or removable storage, such as magnetic and optical discs, RAM, ROM, a carrier wave medium, etc., on which the process and data structures of the present invention can be stored and distributed. The operations can also be distributed via, for example, downloading over a network such as the Internet. We claim [1] An audio/video (AV) stream processing system comprising: a receiving unit (310) which receives an AV stream comprising a content information field and a content field, wherein: the content information field comprises first copy control information, and the content field comprises second copy control information; a determination unit (320) which determines whether the first and second copy control information are different; and a decryption unit (330) for processing the AV stream. [2] The system as claimed in claim 1, wherein the determination unit (320) determines whether copy control mode information of the first and second copy control in- formation are different. [3] The system as claimed in claim 1, wherein the decryption unit (330) stops decrypting content of the AV stream where the first and second copy control information are different. [4] The system as claimed in claim 1, wherein the decryption unit (330) stops generating a decryption key for decrypting content of the AV stream where the first and second copy control information are different. [5] The system as claimed in claim 1, wherein the decryption unit (330, 440) processes content of the AV stream according to one of the first and second copy control information having a higher priority over the other, where the first and second copy control information are different. [6] The system as claimed in claim 5, wherein the second copy control information has priority over the first copy control information where the first and second copy control information are different. [7] The system as claimed in claim 5, wherein the first copy control information has priority over the second copy control information where the first and second copy control information are different. [8] The system as claimed in claim 1, wherein : each of the first and second copy control information comprises a copy control mode of content of the AV stream, and the copy control mode comprises a first mode in which the content is encrypted and copying thereof is absolutely prohibited, a second mode in which the content is encrypted and one time copying thereof is allowed, wherein the second mode being changed to the first mode after the one time copying, a third mode in which the content is encrypted and indefinite copying thereof is allowed, and a fourth mode in which the content is not encrypted and indefinite copying thereof is allowed. [9] The system as claimed in claim 8, wherein the decryption unit comprises: a key generating unit (440) which generates a decryption key for decrypting the content; a content interpreting unit (450) which decrypts the content using the decryption key; and a control unit (430) which controls the key generating unit (440) and the content interpreting unit (450) to stop generating the decryption key or stop decrypting the content where the first and second copy control information are different, and where the first and second copy control information are the same, controls the key generating unit (440) and the content interpreting unit (450) according to the copy control mode. [10] The system as claimed in claim 9, wherein the key generating unit (440) generates the decryption key using information comprising the second copy control in- formation. [11] The system as claimed in claim 9, wherein the control unit (430) controls the key generating unit (440) to generate the decryption key to decrypt the content in response to the copy control mode being one of the first, second, and third mode, and controls the content interpreting unit (450) to output the content, as is, in response to the copy control mode being the fourth mode. [12] The system as claimed in claim 11, wherein the decrypting unit (530) operatively coupled with a storage unit (552) for storing the content. [13] The system as claimed in claim 11, wherein the decrypting unit (440, 530) operatively coupled with a displaying unit (460, 560) for displaying the content. [14] The system as claimed in claim 8, wherein the determining unit comprises: a storage unit (552) for storing the first copy control information; and a comparator unit (554) for comparing the copy control mode of the first copy control information with that of the second copy control information. [15] The system as claimed in claim 8, wherein the decryption unit comprises: a control unit (520) for providing an output signal corresponding to the copy control mode where the first and second copy control information are the same, and for generating a stop signal where the first and second copy control information are different, wherein the control unit outputs the stop signal to the key generating unit (530) where the AV stream is not being played and outputs the stop signal to the content interpreting unit where the AV stream is being played; a key generating unit (530) which generates a decryption key for decrypting the content in response to the signal corresponding to one of the first, second, and third mode, and stops generating the decryption key in response to the stop signal; and a content interpreting unit (540) which decrypts the content using the decryption key, outputs the content, as is, in response to the signal corresponding to the fourth mode, and stops decrypting the content in response to the stop signal. [16] The system as claimed in claim 1, wherein the decryption unit (530) stops processing the AV content where the first and second copy control information are different. [17] The system as claimed in claim 1, wherein the decryption unit (530) processes the AV stream using one of the first and second copy control information providing enhanced copy protection over the other, where the first and second copy control information are different. [18] An audio/video (AV) stream processing system as claimed in claim 1, wherein the audio/video (AV) stream processing system comprising: means (310) for receiving an AV stream comprising a content information field and a content field; means for processing (330) the AV stream; and means (320) for determining whether copy control information of the content in- formation field has been modified. [19] The system as claimed in claim 18, wherein the processing means configured (330) to stop processing the AV stream where the copy control information has been modified. [20] The system as claimed in claim 18, wherein the processing means (330) processes the AV stream using one of the copy control information of the content information field and copy control information of the content field having a higher priority over the other, where the copy control information of the content information field has been modified. [21] An audio/video (AV) stream processing system as claimed in any one of the preceding claims, wherein the content information field comprises first copy control information, and the content field comprises second copy control information; means for processing the AV stream; and means for determining whether the first and second copy control information are different. [22] An audio/video (AV) stream processing system as claimed in any one of the preceding claims, wherein the determination unit (550) for comparing the first copy control information with the second copy control information; and a decryption unit (530) which stops processing the AV stream or processes the AV stream using one of the first and second copy control information having a higher priority over the other, where the first and second copy control in- formation are different. [23] An audio/video (AV) stream processing system as claimed in any one of the preceding claims, wherein the determination unit which determines whether the first copy control information has been modified compared to the second copy control information; and a decryption unit for processing the AV stream. [24] The system as claimed in claim 5, wherein the determination unit (320) establishes priority between the first and second copy control information where the first and second copy control information are different. [25] An audio/video (AV) stream processing system substantially as herein described with reference to the accompanying drawings.

Documents:

1148-delnp-2005-abstract-(20-03-2008).pdf

1148-delnp-2005-abstract-20-03-2008.pdf

1148-delnp-2005-abstract.pdf

1148-delnp-2005-claims-(20-03-2008).pdf

1148-delnp-2005-claims-25-04-2008.pdf

1148-delnp-2005-claims.pdf

1148-delnp-2005-correspondence-others-(20-03-2008).pdf

1148-delnp-2005-correspondence-others-02-04-2008.pdf

1148-delnp-2005-correspondence-others.pdf

1148-delnp-2005-description (complete)-20-03-2008.pdf

1148-delnp-2005-description (complete)-25-04-2008.pdf

1148-delnp-2005-description (complete).pdf

1148-delnp-2005-drawings-(20-03-2008).pdf

1148-delnp-2005-drawings-20-03-2008.pdf

1148-delnp-2005-drawings.pdf

1148-delnp-2005-form-1.pdf

1148-delnp-2005-form-18.pdf

1148-delnp-2005-form-2-(20-03-2008).pdf

1148-delnp-2005-form-2-20-03-2008.pdf

1148-delnp-2005-form-2.pdf

1148-delnp-2005-form-3.pdf

1148-delnp-2005-form-5.pdf

1148-delnp-2005-gpa.pdf

1148-delnp-2005-pct-237-(20-03-2008).pdf

1148-delnp-2005-pct-304.pdf

1148-delnp-2005-pct-373-(20-03-2008).pdf

1148-delnp-2005-pct-search report.pdf

1148-delnp-2005-petition-138-02-04-2008.pdf

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