CN101534429B - Pirate tracking method and system thereof - Google Patents
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Abstract
The invention provides a pirate tracking method and a system thereof. The method adopts a combination elimination technique to determine the pirate from end users according to the detected illicit diffused code word. Using the method to track the pirates solves the existing bottleneck in tracking the pirate, namely the problem of restricts by the cost and technology realization brought by the number of user groups and the increase in the number of user groups. Moreover, the tracking efficiency is high and the benefits of the operators are protected.
Description
Technical Field
The present invention relates to a pirate tracing technology for digital television, and more particularly, to a method and a system for pirate tracing.
Background
With the development of internet video technology and digital television, and the richness of media content, the digital television operation mode that users pay to order their favorite video programs has appeared and gradually popularized, and video content providers are also more inclined to publish programs using digital television systems. In a digital television system, a video program is encrypted and then broadcast to all users, each user has a decryption device at a receiving end, if a user subscribes to a certain program, the corresponding decryption device can recover the plaintext of the program, if the user does not subscribe to the program, the decryption device cannot decrypt the program, and a program packet is discarded.
However, the piracy problem of users becomes a big problem restricting the development of the digital television industry. Piracy in the broadcast mode of digital television is mainly that a pirate attacks a decryption device to obtain a program decryption key and illegally spreads the program decryption key. The user piracy problem becomes an important problem for operators of digital television programs. If this problem is not solved effectively, the pay-per-view mode may be severely affected. Therefore, Traitor Tracing (Traitor Tracing) exists for anti-piracy. Wherein,
fig. 1 is a schematic diagram of dynamic traitor tracing in the related art. Wherein the time required to trace to the traitor is shortened using the feedback information of the pirate.
As shown in fig. 1, the total number of end users present in the system is n, the publishers group users and distribute the same code word for each group, the code words distributed by different groups of users being different. Several colluding pirate users can choose one of the obtained code words to perform illegal diffusion. The distributor monitors the illegally spread code word to deduce from which user group the code word came, and then deduces the pirate user by combining the leakage information and grouping information of the previous code word. If the judgment is not available, the grouping of the users is adjusted according to the information, the code words are redistributed and monitored until the collected information is enough to deduce the pirate.
The above-mentioned "code word" is an abstract concept, and the code word may be different decryption keys for the same program, or may be a media file embedded with different fingerprint information.
In the related art, a binary tree (or multi-tree) search mode can be adopted to determine a pirate user when judging the pirate, and a deterministic tracking strategy can be constructed only when the number of user groups is greater than the number of collusion users. Taking the case that the relationship between the maximum user group number r and the upper bound p of pirate user number satisfies r 2p +1 as an example, the tracing strategy stores possible innocent users by using one user group I, and stores possible p pirate users by using the remaining 2p user groups, wherein each user group has at least one pirate user among the users in { Li, Ri }. If the monitored illegal spreading code word is the code word allocated to I, dividing I into two parts of Li and Ri with the same number of users, and emptying I; if the monitored code words are allocated to Li, combining Ri and I, and dividing Li into Li and Ri; if the monitored code word is from Ri, combining Li and I, and dividing Ri into two parts of Li and Ri. And after each step, the number of users in a user group is halved until a code word allocated to a user group only containing one user is monitored, a pirate user is traced, the user is disconnected from the system, and the steps are continued until all the pirate users are traced.
In the dynamic tracking policy of r 2p +1, the number of packets in the first few steps of the search process is usually much smaller than the maximum number of packets r. In practical applications, due to the complexity of the multi-decryption key system design or the limitation of the transmission bandwidth, the maximum number of packets is often limited, or a higher cost must be paid to increase the maximum number of packets, so the above dynamic tracking policy cannot fully utilize the predetermined system conditions, and the search efficiency is affected.
Disclosure of Invention
The invention aims to provide a pirate tracing method, which traces the pirate by adopting a combined elimination method, solves the bottleneck problem of the prior pirate tracing, namely the problem of limitation of conditions such as cost, technical realization and the like caused by the increase of the user group number and the user group number, has high tracing efficiency and maintains the benefits of operators.
The invention also aims to provide a traitor tracing system, which solves the bottleneck problem of the traitor tracing in the prior art and has high tracing efficiency; and the benefits of the operator are maintained.
To achieve the above object, the present invention provides a method for tracing a pirate, comprising: determining pirates in the terminal users by adopting a combined elimination method according to the monitored illegally spread code words, wherein the determining pirates in the terminal users by adopting the combined elimination method according to the code words comprises the following steps:
step 1, grouping the current terminal users and distributing different code words to each group;
step 2, monitoring illegal diffused code words of the terminal user;
step 3, determining at least one of the current colluders from the group where the code word is located according to the code word;
step 4, eliminating the combination of the suspected collusion group in the combination C (U, T) of the current collusion group
To obtain the combination C \ C of the remaining suspected collusion groups1Wherein U is a terminal user, T is the number of any possible colluders, G is the number of groups into which the U terminal users are divided, C \ C1To exclude combination C1 from combination C;
drawings
Step 5, judging whether at least one colluder exists in the combination of the remaining suspected collusion groups;
step 6, if the judgment result is yes, the collusion person is determined to be a pirate;
and 7, if the judgment result is negative, grouping the terminal users according to the combination of the remaining suspected collusion groups, performing the steps 2 to 5, and repeating the steps until at least one colluder exists in the combination of the remaining suspected collusion groups.
In order to achieve the above object, the present invention further provides a pirate tracing system, which comprises a plurality of terminals, wherein the terminals can be specifically understood as a set-top box or a user combined with an IC card; wherein, this system still includes:
the monitoring unit is used for monitoring the code words illegally spread by the terminal user;
the tracking unit is connected with the monitoring unit and used for determining a pirate in the terminal user by adopting a combination elimination method according to the monitored code word;
the grouping unit is connected with the tracking unit and used for grouping the current terminal user according to the tracking result of the tracking unit and transmitting the grouping result to the distribution unit;
a distribution unit connected with the grouping unit and the terminal for distributing different code words to each group according to the grouping result and sending the code words to the terminal
The device also comprises a judging unit which is respectively connected with the grouping unit and the monitoring unit, and the judging unit carries out the following processing:
exclusion of combinations of suspect collusion groups in combinations C (U, T) of current collusion groupsTo obtain the combination C \ C of the remaining suspected collusion groups1Wherein U is a terminal user, T is the number of any possible colluders, G is the number of groups into which the U terminal users are divided, C \ C1To exclude combination C1 from combination C; judging whether at least one colluder exists in the combination of the remaining suspected collusion groups; if the judgment result is yes, the colluder is determined to be a pirate, if the judgment result is no, the grouping unit is used for grouping the terminal user according to the combination of the remaining suspected collusion groups, and the judgment unit repeats the processing until at least one colluder commonly exists in the combination of the remaining suspected collusion groups.
The method has the advantages that the combined elimination method is adopted to track the pirates, so that the bottleneck problem of the traditional pirate tracking, namely the problem of the limitation of the conditions such as cost, technical realization and the like caused by the increase of the user group number and the user group number is solved, and the tracking efficiency is high; and the benefits of the operator are maintained.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a schematic diagram of a pirate tracing system in the prior art;
FIG. 2 is a flow chart of a pirate tracing method implemented by the invention;
FIG. 3 is a block diagram of a pirate tracing system according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following embodiments and the accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.
The present invention provides a pirate tracing system, as shown in fig. 3, the system includes a plurality of terminals; in addition, the system further comprises:
a monitoring unit 301, configured to monitor an illegally spread codeword for a terminal user; and the tracking unit 302 is connected with the monitoring unit 301 and is used for determining a pirate in the end user by adopting a combination elimination method according to the monitored code word.
Therefore, the pirate is tracked by adopting the combined elimination method, the bottleneck problem of the conventional pirate tracking is solved, the tracking efficiency is high, and the benefits of operators are maintained.
Wherein, the terminal can be a set-top box combined with a certain IC card.
Further, in the present embodiment, the system further includes a grouping unit 303 and an assigning unit 305; the grouping unit 303 is connected to the tracking unit 302, and is configured to group current end users according to the tracking result of the tracking unit 302, and transmit the grouping result to the allocating unit 305;
an allocating unit 305, configured to allocate a different code word to each packet according to the grouping result of the grouping unit 303, and send the code word to the terminal.
As shown in fig. 3, the system further includes an output unit 304, wherein the output unit 304 is connected to the tracing unit 302 for outputting the traced pirate.
The invention also provides a pirate tracing method, which comprises the following steps: and determining pirates in the terminal users by adopting a combined elimination method according to the monitored illegally diffused code words.
By adopting the combined elimination method to track the pirates, the bottleneck problem of the traditional pirate tracking is solved, namely the problem of the limitation of the conditions such as cost, technical realization and the like caused by the increase of the user group number and the user group number is solved, the tracking efficiency is high, and the benefits of operators are maintained.
In the present invention, after determining the pirate, the method further comprises: the pirate is output. Thus, the connection of the pirate terminal can be disconnected according to the output information of the pirate.
In the invention, the pirate in the terminal user is determined by adopting the combined elimination method according to the code words, and the following mode can be adopted: step 1, grouping current terminal users and distributing different code words to each group; step 2, monitoring illegal diffused code words of the terminal user; step 3, determining at least one of the current colluders from the group where the code word is located according to the code word; step 4, eliminating the combination of the suspected collusion groups according to the combination of the current collusion groups to obtain the combination of the remaining suspected collusion groups; step 5, judging whether at least one colluder exists in the combination of the remaining suspected collusion groups; and 6, if the judgment result is yes, determining that the collusion person is a pirate.
In addition, the method further comprises: judging whether all colluders are found; if the judgment result is yes, all pirates are tracked, and the tracking process is finished. If the judgment result is negative, repeating the steps 1 to 6 until all the colluders are found.
The present invention will be described in detail below with reference to fig. 2 and 3.
First, the number of users sharing a terminal in the system is set to U, the number of colluders is set to T, and the maximum number of user packets that can be used is set to G. Thus, at the start of tracking, arbitrarily selecting T from U end users may be a collusion group, denoted as C, whose combination is | C | ═ C (U, T).
In step 206, it is determined whether at least one colluder can be determined according to the combination of the remaining suspected collusion groups, and the following method may be adopted in this embodiment: judging whether at least one colluder exists in the combination of the residual collusion groups;
if the judgment result is no in step 206, it indicates that the pirate cannot be determined, the process returns to step 201 to exclude more remaining suspected user groups until the pirate can be determined according to the combination of the remaining suspected collusion groups. Wherein, the following mode can be adopted:
the grouping unit 103 groups users according to the remaining suspected collusion combinations, the allocating unit 305 reallocates codewords to the terminal, and the monitoring unit 301 monitors illegally diffused codewords; and if the illegally leaked code words are monitored, the suspected collusion group is excluded according to the information. Note that the set of suspect collusion combinations excluded only from this step of feedback information is B2Then there is
The number of suspected combinations that can be practically ruled out according to this step may be less than | B2Because of this suspected collusion group B2May also include C1In common combination, i.e.
Therefore, the combination of suspected collusion groups that can be effectively excluded in this step is denoted as C2Then C is2＝B2-C1∩B2；
By analogy, note that the set of suspect combinations that are excluded only from the feedback information of step i is BiThe set of suspected combinations that can be effectively eliminated in step i is denoted as CiThen BiAnd CiThe relationship of (a) to (b) is as follows:
C1＝B1
C2＝B2-C1∩B2
C3＝B3-(C1∪C2)∩B3
in the ith step, the combinations of the remaining suspected collusion groups are
If a pirate can be deduced according to the rest suspect combinations, outputting the pirate, and disconnecting the connection between the pirate terminal and the system;
If the number K of colluders determined in step 206 is less than T, which indicates that all pirates are not found, go back to step 201 to trace the pirates. In this case, the current number of terminal users is U-K, the number of colluders is T-K, and the maximum number of user packets that can be used is still G, at the start of each trace. Thus, at the start of the trace, arbitrarily selecting T-K from U-K end users may be the combination of the current collusion group, and so on until U-K is 0.
As described above, when the combination exclusion method is used, the number of combinations | C to be excluded per one time is determinediIs close to
The ratio of the number of combinations excluded to the total number of combinations, referred to as the exclusion ratio, may be:
where r can be viewed as an estimate of the convergence speed of the combined elimination method. It can be seen that the convergence rate of the trace increases with increasing G and decreases with increasing T.
Therefore, as can be seen from the above embodiments, the method solves the bottleneck problem of traitor tracing in the prior art, that is, the problem of being limited by the user group number and the conditions of cost, technical implementation and the like caused by the increase of the user group number, and has high tracing efficiency and maintains the benefits of operators.
The following description will be made of a practical example. For example, for a total number of users U-100 with T-6 collusion, the maximum number of user groups G-5 can be used, each group having 20 people.
Thus, at the start of tracing, arbitrarily selecting 6 from 100 end users may be collusion group, denoted as C, whose combination is | C | ═ C (U, T), i.e., it is
1) Tracking starts, the grouping unit 303 uniformly groups the users into 5 groups, and the allocating unit 305 allocates different codewords to each group, for example, the allocated codewords are {1, 2, 3, 4, 5 };
2) the monitoring unit 301 monitors the illegally spread codewords, if the collusion group illegally spread codewords are 1;
3) the judging unit 302 judges according to the monitored informationAt least one of the colluders is known to be from group 1, and not all from {2, 3, 4, 5} group; combining according to current colluders
Combinations for eliminating suspect colluders
To obtain a combination of the remaining colluders as
A plurality of;
4) whether at least one colluder can be determined from the combination of the remaining suspected collusion groups can be judged, and the following method can be adopted in the embodiment: judging whether at least one colluder exists in the combination of the residual collusion groups; if the judgment result is yes, the collusion person is determined to be a pirate, and at this time, the output unit 304 outputs the pirate and disconnects the connection between the pirate terminal and the system;
5) and if the judgment result shows that no colluders exist in the combination of the remaining collusion groups, the pirates cannot be determined, and repeating the steps 1) -4) until more remaining suspected user groups are excluded until the pirates can be determined according to the combination of the remaining suspected collusion groups. Wherein, the following mode can be adopted:
the grouping unit 103 groups users according to the remaining suspected collusion combinations, the allocating unit 305 reallocates codewords to the terminal, and the monitoring unit 301 monitors illegally diffused codewords; and if the illegally leaked code words are monitored, the suspected collusion group is excluded according to the information. Note that the set of suspect collusion combinations excluded only from the feedback information of this step is B2Then there is
The number of suspected combinations that can be practically eliminated according to this step may be less than
Because this time the suspect collusion group B2May also include C1In common combination, i.e.
Therefore, the combination of suspected collusion groups that can be effectively excluded in this step is denoted as C2Then C is2＝B2-C1∩B2；
By analogy, note that the set of suspect combinations that are excluded only from the feedback information of step i is BiRecord the set of suspect combinations effectively excluded in step i as CiThen BiAnd CiThe relationship of (a) to (b) is as follows:
C1＝B1
C2＝B2-C1∩B2
C3＝B3-(C1∪C2)∩B3
in the ith step, the combinations of the remaining suspected collusion groups are
If a pirate can be deduced according to the rest suspect combinations, outputting the pirate, and disconnecting the connection between the pirate terminal and the system;
6) judging whether all 6 pirates are found, namely judging whether the number of colluders in 5) is 6, if so, indicating that all the pirates are found through the steps, and ending the tracking process.
If the number K of colluders determined in step 5) is less than 6, which indicates that all pirates are not found, repeating steps 1-5) to trace the pirates. In this case, the current number of terminal users is 100-K, the number of colluders is 6-K, and the maximum number of user packets that can be used is G at the beginning of each trace. Thus, at the start of the trace, arbitrarily selecting 6-K from 100-K end users may be the combination of the current collusion group, and so on until 6-K is 0.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (6)
1. A method for tracking a pirate, the method comprising: determining pirates in the terminal users by adopting a combined elimination method according to the monitored illegally spread code words,
wherein the determining of the pirate in the end user by adopting a combined elimination method according to the code words comprises:
step 1, grouping the current terminal users and distributing different code words to each group;
step 2, monitoring illegal diffused code words of the terminal user;
step 3, determining at least one of the current colluders from the group where the code word is located according to the code word;
step 4, eliminating the combination of the suspected collusion group in the combination C (U, T) of the current collusion group
To obtain the combination C \ C of the remaining suspected collusion groups1Wherein U is a terminal user, T is the number of any possible colluders, G is the number of groups into which the U terminal users are divided, C \ C1To exclude combination C from combination C1；
Step 5, judging whether at least one colluder exists in the combination of the remaining suspected collusion groups;
step 6, if the judgment result is yes, the collusion person is determined to be a pirate;
and 7, if the judgment result is negative, grouping the terminal users according to the combination of the remaining suspected collusion groups, performing the steps 2 to 5, and repeating the steps until at least one colluder exists in the combination of the remaining suspected collusion groups.
2. The method of claim 1, further comprising: and outputting the pirate.
3. The method of claim 1, further comprising:
judging whether all colluders are found;
if the judgment result is yes, the tracking is finished.
4. The method of claim 3, wherein if the determination of whether all colluders are found is negative, then repeating steps 1 through 7 until all colluders are found.
5. A pirate tracing system comprises a plurality of terminals; characterized in that, the system also includes:
the monitoring unit is used for monitoring the code words illegally spread by the terminal user;
the tracking unit is connected with the monitoring unit and used for determining a pirate in the terminal user by adopting a combination elimination method according to the monitored code word;
the grouping unit is connected with the tracking unit and used for grouping the current terminal user according to the tracking result of the tracking unit and transmitting the grouping result to the distribution unit;
the distribution unit is connected with the grouping unit and the terminal and used for distributing different code words to each group according to the grouping result and sending the code words to the terminal;
the device also comprises a judging unit which is respectively connected with the grouping unit and the monitoring unit, and the judging unit carries out the following processing:
exclusion of combinations of suspect collusion groups in combinations C (U, T) of current collusion groups
To obtain the combination C \ C of the remaining suspected collusion groups1Wherein U is a terminal user, T is the number of any possible colluders, G is the number of groups into which the U terminal users are divided, C \ C1To exclude combination C from combination C1(ii) a Judging whether at least one colluder exists in the combination of the remaining suspected collusion groups; if the judgment result is yes, the colluder is determined to be a pirate, if the judgment result is no, the grouping unit is used for grouping the terminal user according to the combination of the remaining suspected collusion groups, and the judgment unit repeats the processing until at least one colluder commonly exists in the combination of the remaining suspected collusion groups.
6. The system of claim 5, further comprising an output unit coupled to the tracking unit for outputting the pirate.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1442978A (en) * | 2002-01-28 | 2003-09-17 | 株式会社东芝 | Data communication system, encryption device and deciphering device |
| CN1554163A (en) * | 2001-01-26 | 2004-12-08 | �Ҵ���˾ | Method for tracing traitor receivers in a broadcast encryption system |
| CN1991853A (en) * | 2005-12-30 | 2007-07-04 | 国际商业机器公司 | Method and system for tracing traitor in a broadcast encryption system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1554163A (en) * | 2001-01-26 | 2004-12-08 | �Ҵ���˾ | Method for tracing traitor receivers in a broadcast encryption system |
| CN1442978A (en) * | 2002-01-28 | 2003-09-17 | 株式会社东芝 | Data communication system, encryption device and deciphering device |
| CN1991853A (en) * | 2005-12-30 | 2007-07-04 | 国际商业机器公司 | Method and system for tracing traitor in a broadcast encryption system |
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| JP特开2003-289296A 2003.10.10 |
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