CN103873895B - A kind of DVB/IPTV bimodulus interactive service protects system - Google Patents

Abstract

A kind of DVB/IPTV bimodulus interactive service protects system; the system includes client-end subsystem, front end subsystem, Certificate Authority subsystem, subscriber management system, program Workflow Management System, program information management system part; wherein client-end subsystem, CA front ends subsystem, Certificate Authority subsystem are major part, and subscriber management system, program Workflow Management System, program information management system are peripheral accessory system.The system supports DVB and IPTV video scramblings, the deep-controlled strategy of controllable scrambling and adaptive scrambling, the key management mode for supporting more than three kinds of programme content are provided, the key length selection of more than 128, the distributed encapsulation of large scale content, with the support supervised to the content safety based on digital watermarking and business.System supports DVB/IPTV bimodulus; introduce key updating batch processing strategy and distributed authentication mandated program; key real-time update and the distribution of million userbases are provided; reduce overhead; enhance the ability of whole key updating; the security of system is improved, flexible and changeable protection mechanism is provided for pay TV business.

Description

A kind of DVB/IPTV bimodulus interactive service protects system

Technical field

It is to be related to broadband interdynamic TV system bidirectional asymmetrical digital specifically the present invention relates to information security field The key technology of television system.

Background technology

In the development of the interdynamic video systems such as iDTV (digital television interaction), IPTV (IPTV), Protecting for interdynamic video business tine is just turning into the important bottleneck that influence interdynamic video business is able to promote with control, and it is related to interior Hold the technology in terms of protection, transmission protection, access control, piracy tracking and contents supervision.

Traditional video traffic protection system is set up in unilateral network, in order to which the mandate of scrambled control word, user are believed Breath and the important content such as management information entirely be transferred to client, employ the basic thought set up defenses in depth, system architecture is complicated, Security is not high, easily by hack.

Because traditional Broadcasting Cable Network belongs to radio network, its video traffic protection system also necessarily broadcaster is determined Formula.In this manner, service front-end does not know about the situation of client, it is impossible to which the validity and reliability of client is tested Card, client can not also verify the validity and reliability of front end, reception that can only be passive, this and video traffic protection system pin To user and its watch behavior carry out pay per view original intention there is contradiction.

In traditional video traffic protection system, front end generates the security information that may be needed encryption to all users simultaneously Transmitted, on the one hand add network load, wasted massive band width, larger delay, the opposing party are brought to Consumer's Experience Face because the presence of a large amount of encryption information, adds the possibility that saboteur cracks encryption system again, forms potential safety hidden Suffer from.

Traditional video traffic protection system, as its key distribution mechanism, adds implementation using complicated multi-enciphering Difficulty, easily produce security breaches.Often increase a key, the difficulty to the generation of key, distribution, management just has significantly The lifting of degree.As long as saboteur destroys any one link therein, it is possible to whole system is effectively destroyed, even taking The ancillary methods such as many cryptographic algorithm backups, also can not fundamentally solve this defect.

Traditional interactive service protection system is the charge system of radio network, not to the authentication of user, is not suitable for Bilateral network；The opening of content data and internet causes very big difficulty to piracy tracking and contents supervision.

Protection to video frequency program typically uses two ways：Pre-packaged mode and real-time encrypted mode.When need encapsulation Video frequency program is more or during larger video, because CPU disposal abilities are limited, program packaging efficiency is relatively low.

For legacy CA system, the collection and transmission of video source are all by the way of plaintext, and the security to video source is made Into threat.In addition, existing storage mode, whether directly stores or receives file encryption storage, all there is potential safety hazard.

Common signal scrambling technique can not realize the selection control to scrambling depth, it is impossible to distinguish important and insignificant information, Scrambling intensity is often excessive, and scrambling effect is not good.

The content of the invention

Based on above-mentioned, a kind of DVB/IPTV bimodulus interactive service protection system of present invention proposition, a kind of DVB/IPTV bimodulus Interactive service protects system, it is characterised in that：The system include client-end subsystem, front end subsystem, Certificate Authority subsystem, The parts such as subscriber management system, program Workflow Management System, program information management system.Wherein client-end subsystem, front end subsystem System, Certificate Authority subsystem are major part, and subscriber management system, program Workflow Management System, program information management system are outer Enclose accessory system.The system is included in service protection CAServer servers, empowerment management DRMServer and client STB The part of CAClient modules three, wherein CAServer servers correspondence front end subsystem, empowerment management DRMServer correspondence certifications CAClient modules correspondence client-end subsystem in authorization subsystem, client STB.

Described client-end subsystem (abbreviation client) is using layering and modular structure, and client is divided into from top to bottom to be connect Mouth layer, key-course and operation layer；Interface layer provides the task interface of standard, receives customer service instruction and user profile, interface Layer to user feedback system implementing result or descrambling after programme content；Key-course is responsible for business module list, according to industry The corresponding operation layer module of instruction calls of being engaged in completes corresponding business, and there is provided each business module for the operation of each business module of coordination Data exchange mechanism, and compile the implementing result of each industry module and feed back to interface layer；Operation layer includes multiple business moulds Block, including：Order module, business application module, business acquisition module；Order module and complete registration, purchase, query function；Shen Please module completion programme application, program request application, broadcast application, live application, arranging key function；Business acquisition module is completed Demultiplexing, decryption ECM, descrambled program stream, the checking legal sexual function of program；Wherein, demultiplexing function is whole using tradition DVB-CA End is synchronous with the foundation of front end subsystem, and receives, demultiplexes, and obtains ECM and program stream；Decrypt ECM functions and use the meeting consulted Words key ECM is decrypted acquisition descrambled control words CW；The Control Word that descrambled program stream function is obtained using decryption is called AES or CSA Descrambling Algorithms descramble to program stream, and obtained DVB/IPTV programs are streaming into key-course；Verify program The legitimacy mark watermark that legal sexual function is used to extract in program stream.

Described front end subsystem further by encapsulating subsystem, pre-packaged subsystem, secure memory subsystem structure in real time Into.Encapsulation subsystem is used for real-time online encapsulation and protection to programme content in real time, and pre-packaged subsystem is used in program The offline encapsulation held and protection.In real time encapsulation subsystem and pre-packaged subsystem can select as needed one of them use or Person is used in conjunction with.Secure memory subsystem can select to use as needed.Described front end subsystem includes：Control word is generated Device (CWG), ECM makers (ECMG), watermarking algorithm (WEA) and Common Scrambling Algorithm (CSA)；The effect of front end subsystem It is generation control word, calls CSA to scramble the programme content from program Workflow Management System；The control word of front end subsystem Generator generates control word based on system key, using DVB Common Scrambling Algorithms (CSA) to from program Workflow Management System Programme content carry out Scrambling Operation；Front end subsystem simultaneously also using session key to control word be encrypted generation it is traditional ECM；Programme content after scrambling passes to program distribution system with ECM and carries out multiplexing transmission；Front end subsystem will be between fixation Every regenerating scrambled control word, it is ensured that the transmission safety of programme content；Under program request interactive mode, front end subsystem is simultaneously It is responsible for receiving the broadcasting control information of user, and scrambling and program streaming is adjusted.

Described Certificate Authority subsystem is by service handling module, business cipher key SK update modules, bidirectional identification protocol, SK Agreement protocol, timer, online user's list section composition, Certificate Authority subsystem receive application of the user to programme content, Business cipher key SK is obtained by certification and negotiation, and periodically carries out key updating；The service handling of Certificate Authority subsystem Module is the interface with user, starts corresponding operation flow according to the program application of user, in the cooperation of Subscriber Management System Under application to user and its identity information, credit information carry out legitimacy and validation verification；For legal, effective Shen Please, Certificate Authority subsystem provides key agreement mechanisms and user and consults to obtain session key, and by session key and its correlation Programme information is sent to front end subsystem by safe lane, and Certificate Authority subsystem is by the body with fixed intervals again to user Business cipher key is verified and regenerated to part.

Described CAServer servers include receiving port, sending port, descrambler, the part of key port four；It is described Empowerment management DRMServer include CA ports, STB ports, certification and url management module, program key management module and control Molding block；Described CAClient modules include descrambler and key port two parts, are key-course, business by distinguishing hierarchy Layer, operation layer is core layer, realizes the registration of user, service authorization acquisition of information, the descrambling function of program.

System design KDC (Key Distribution Center, KDC) is the encryption and decryption of client File provides business cipher key, and KDC first obtains the segmentation situation of client cryptograph files, when for n subfile, Corresponding 1 to n unduplicated random sequence is generated, client sends ciphertext Ziwen to storage server successively according to random sequence Part；Storage server sets up new file, and the ciphertext subfile received is write into new file, until ciphertext subfile is sent.

The system is directed under bandwidth varying environment to program scrambling and the demand of publicity, and design implements controllable scrambling depth Strategy and adaptive scrambling technology, scrambling parameter is dynamically adjusted according to carrier network situation, different compressed encodings and code check, While protection business, data processing amount is reduced, the scrambling expense of video is reduced.Control of the system for realization to scrambling depth System, the method that (n1, n2) is counted using double upper limits to the method for counting of I frames and I- macro blocks so that count upper-limit n values all can use with Any scrambling depth d can be selected；To arbitrary d, if：1) 1/d is integer, then makes n1=1/d, n2=1；2) 1/d is not It is integer, then 1/d is expressed as fraction, and the greatest common divisor r of molecule denominator is obtained with Euclidean algorithm, 1/d is about obtained afterwards =a/b, order：Wherein a and b are mutual prime rwmbers；

To I frame count c1, the c2 found, when c1 reaches upper limit n1, Scrambling Operation is performed to present frame；On c2 reaches When limiting n2, two counters are all reset, c1=c2=0；

The set-up mode of two kinds of scrambling depth is provided in the application：1) n modes are set, and n is the scrambling upper limit, and actual setting adds Depth is disturbed for 1/n；2) d modes are set, and d is scrambling depth, and scrambling upper limit n values are determined using above-mentioned double upper limit method of counting.

The efficiency that the system is packaged for the interactive large scale programme content of high definition, design is implemented based on intelligence The distributed pre-packaged technology of thought is acted on behalf of, by means such as intelligentized segmentation, scheduling, collaborations, is ensureing security and one On the premise of cause property, the pre-packaged speed to large scale programme content is improved.The system model uses C/S structures, pre-packaged System end is server, and video input is client, C/S model is also used in pre-packaged internal system, by master server and generation Server group is managed into proxy server is server end for master server, and master server is client；Add to needing to encapsulate Close video, initially enters master server, and master server is judged according to video size, chooses whether to need proxy server Encapsulation；If being not required to agency to perform, do not split video file, master server is directly packaged encryption；If desired agency performs, Video file is then divided into several segments according to the algorithm of design, then the idle proxy server on automatic search network, will The video being segmented sends available agency to, allows its execute encapsulation function；After proxy server encapsulation is completed, then return in time Back to main server-side, the segmentation of return is recombinated by main server-side, a complete packaged " original is reverted to Video " file.

The system has used dynamic key to update and distribution technique；Dynamic key updates is divided into two stages with distribution, point It is not that business cipher key switching phase and dynamic service key push the stage；The business application mould of Certificate Authority subsystem and client Block produces business cipher key SK by key agreement protocol.After successful negotiation key, user profile and its corresponding SK will be protected Online user's list is stored to, timer is activated；When reaching specified time interval, by SK update modules to online user's list In user re-start Authentication and Key Agreement, more new session key SK, wherein, business cipher key SK is passed through using SSL modes Safe lane is distributed；In addition to business cipher key SK, Control Word and system key MK are also included in the system；Wherein control word CW renewal is unrelated with user, is updated by appointed interval.

System has been respectively adopted cipher key hierarchy and updated and group key management during business cipher key is updated；Described Cipher key hierarchy updates, i.e., DRM authorization Verification System is when carrying out key updating, and upper level DRM Server are only in local area DRM Server carry out key updating, and without directly providing service to user, and group key management is by broadcasting service and other Value-added service is treated with a certain discrimination, if user has had subscribed to the broadcasting service specified, then use other business in switching When, DRM system does not update to broadcasting service cryptographic key, only key updating processing is carried out to value-added service, in the process of key updating The middle minimum nodes for finding group key management.

System scrambling module in the pre-packaged module of front end subsystem uses two kinds of algorithms of CSA and AES, according to environment Need to change scrambling algorithms in real time, encrypting module encrypts CW using aes algorithm, support CBC (inverse block linking scheme), OFB (output feedback mode), CFB (cipher feedback pattern), CTR (technology mode), five kinds of encryption moulds of ECB (electronic codebook mode pattern) Entitlement Control Message ECM is encrypted formula, is arbitrarily chosen in front terminal system configuration parameter structure, realizes information flow Secrecy transmission.

The system uses double layer encryption strategy, includes two encryptions level, i.e. single-unit mesh relevant layers (PRL:Program ) and business relevant layers (SRL RelatedLayer:Service Related Layer), implement for PRL layers to be based on cw pairs of control word The scrambling of video content, SRL layers based on business cipher key by encrypting generation business related control information (SRI:Service RelatedInformation), i.e. Entitlement Control Message ECM, is scrambled using CW as key, calls Common Scrambling Algorithm CSA to complete Direct scrambling protection to programme content to be transmitted, encrypts using business cipher key SK as key, AES is called, to Control Word Encryption, form Entitlement Control Message (ECM), CW ensures the safe transmission of programme content, while CW and SK separation, also cause The scrambling of programme content is unrelated with user, reduces the complexity of system.

The system introduces key updating batch processing strategy, makes key real-time update and the distribution of million userbases, it is wrapped Include an authorization server (AS, Authentication Server) and multiple key servers (KS, Key Server) two Part, wherein authorization server are as tree root, the key message of distribution service protection, and by key server manage between take over Manage all users；Authorization server, including user authentication module, key server module and user's authorization module, authorize clothes The access (leaving) that business device receives user by SSL safe lanes is asked, and carries out authentication to user；Key server, Including key production module, key distribution module and key management module, key server is produced by key production module Pseudo random number, is used as demand (telecommunication) service key to be distributed；Group key point for authorizing group membership is realized by key distribution module Hair；Key management module carries out data interaction with authorization server, sends addition (deletion) mandatory member's in authorization server During instruction, key management module notifies key production module to produce new demand (telecommunication) service key, and then key management module will be through The program request key crossed after updating is sent to authorization server, and close to specified user key node progress by key distribution module Key updates.

The system effectively solves technical problem proposed by the present invention.

Brief description of the drawings

Fig. 1 is system framework figure；

Fig. 2 is the basic block diagram of client；

Fig. 3 is the basic block diagram of front end subsystem；

Fig. 4 is Certificate Authority subsystem structure figure；

Fig. 5 is system general module structure chart；

Fig. 6 is distributed pre-packaged system model figure；

Fig. 7 is key updating Path selection figure.

Embodiment

DVB the and IPTV interactive services protection system of the present invention includes client-end subsystem, front end subsystem, Certificate Authority The parts such as subsystem, subscriber management system, program Workflow Management System, program information management system.Wherein client-end subsystem, preceding Terminal system, Certificate Authority subsystem are major part, subscriber management system, program Workflow Management System, program information management system Unite as peripheral accessory system.The system includes service protection CAServer servers, empowerment management DRMServer and client The part of CAClient modules three in STB, wherein CAServer servers correspondence front end subsystem, empowerment management DRMServer CAClient modules correspondence client-end subsystem in correspondence Certificate Authority subsystem, client STB.

Referring to accompanying drawing 2, the basic structure of client-end subsystem (abbreviation client) is as follows：Client is that set top box or TV are carried Access, the programme information provided according to user, be responsible for and subscriber management system, Certificate Authority subsystem for transparent programme content With front terminal system interaction, descramble key is obtained, implements the descrambling work to scrambled program, Conditional Access is realized and has ready conditions Ability to play.The order module of client interacts transmission subscriber identity information, user with subscriber management system by safe lane The contents such as credit information, complete the functions such as registration, purchase, provide the user the interaction mechanism for inquiring about its identity and credit information； The business application module of client interacts transmission subscriber identity information with the service handling module of Certificate Authority subsystem and right Program, programme, the application of program category (program request, broadcast, live), and be responsible for consulting generation business with Certificate Authority subsystem Key, passes to business acquisition module；The business acquisition module of client from preceding terminal system to synchronously obtaining the program scrambled Content is decrypted and descrambled work, and submits the broadcasting control information of user (F.F., fast to CA under program request interactive mode Move back, stop), realize the interactive operation to program stream.

Client is easy to the renewal and upgrading of system, to improve the compatible and spirit of system using layering and modular structure Activity.Client is divided into interface layer, key-course and operation layer from top to bottom.Interface layer is responsible for the task interface of offer standard, connects Receive the service order (such as registration, order, program request, broadcast, live, F.F., rewind, stopping) of user and its relevant information is (such as Number of set-top box, identification card number, letter of identity of user etc.), submit to control module.Meanwhile, interface layer also is responsible for anti-to user Programme content after feedback system implementing result or descrambling.

Key-course is responsible for business module list, calls corresponding operation layer module to complete according to service order corresponding Business.

Operation layer is divided into several business modules, and each business module completes relatively independent business.Main business mould Block includes：Order module, business application module, business acquisition module.Order module and complete registration, purchase, query function.Application Module completes programme application, program request application, broadcast application, live application, arranging key function.Business acquisition module completes solution Multiplexing, decryption ECM, descrambled program stream, the checking legal sexual function of program.Wherein, demultiplexing function uses tradition DVB-CA terminals It is synchronous with the foundation of front end subsystem, and receive, demultiplex, obtain ECM and program stream；Decrypt ECM functions and use the session consulted Key ECM is decrypted acquisition descrambled control words CW；The Control Word that descrambled program stream function is obtained using decryption calls solution Disturb algorithm (AES or CSA algorithms) to descramble program stream, obtained DVB/IPTV programs are streaming to key-course；Checking The legitimacy mark watermark that the legal sexual function of program is used to extract in program stream.

The main information stream of client includes：Conditional Access (CA), have ready conditions broadcast (CP) and piracy tracking (PT). Defined according to information flow, client function is made up of CA, CP, PT, be respectively：

Wherein DS is descrambling function, and C is the transport stream after scrambling or encryption, and CW is the control of control word generator generation Word, K is business cipher key, and D is decryption function, and EX obtains ECM (Entitlement Control Message) operation letter to be demultiplexed from transport stream Number；WD is legitimacy watermark extracting function, and valid is detects whether successfully mark, and valid=1 is represented to detect successfully, carrier In comprising watermark W, valid=0 represents that detection is unsuccessful, does not find legitimacy watermark W in carrier；FE is that finger water-print is embedded in letter Number, α, β ∈ { 0,1 } ∧ α ≠ β.

Referring to accompanying drawing 3, front end subsystem basic structure is as follows：Front end subsystem includes control word generator (CWG), ECM Maker (ECMG), watermarking algorithm (WEA) and Common Scrambling Algorithm (CSA), its main function are generation control words, are called CSA is scrambled to the programme content from program Workflow Management System, realizes that encapsulation is (RP) and pre-packaged (PP) in real time.In addition, In order to tackle the transmission and interference of illegal programs, pass through embedded legitimacy digital watermarking mark during encapsulating in real time and be pre-packaged Know W to realize the broadcasting CP that has ready conditions, corresponding client-end subsystem whether there is legitimacy water by verifying in program transport streams Marking knows W actually to control the broadcast of program on the subscriber terminal.

Defined according to information flow, front terminal system function is：

Wherein C is the transport stream after scrambling or encryption, and K is business cipher key, and WE represents legitimacy watermark imbedding function, S generations Table scramble function, E represents encryption function, and T is carrier, and W is that legitimacy watermark generator generates legitimacy watermark information.

α,β∈{0,1}∧α≠β。

The control word generator of front end subsystem generates control word based on system key, is calculated using DVB common scramblings Method (CSA) carries out Scrambling Operation to the programme content from program Workflow Management System (such as CDN content management server).Before Terminal system is also encrypted to control word using session key and generates traditional ECM simultaneously.Programme content and ECM after scrambling Pass to program distribution system and carry out multiplexing transmission.In addition, front end subsystem will regenerate scrambled control word with fixed intervals, Ensure the transmission safety of programme content.Under program request interactive mode, front end subsystem also is responsible for receiving the broadcasting control of user simultaneously Information (F.F., rewind, stopping etc.) processed, and scrambling and program streaming are adjusted.

The processing procedure of condition reception front end is as follows：

1) embedded legitimacy watermark：In order to which supports conditions are broadcasted and copyright protection, pass through water mark embedding device WEA copyright water Print algorithm and legitimacy watermarking algorithm and be embedded in copyright and legitimacy watermark in TS transport streams.Copyright watermark bit sequence is taken by certification Device be engaged according to front end mark and business information generation.Legitimacy watermark bit sequence is generated by regulator.

2) CW is generated：For MPTS and complicated front end system, CW is generated by independent scrambler.For single-unit The front end system of program transport stream and low cost, CW is generated by CWG.According to the initial vector provided by EIS (event scheduling system) (IV) and service identification (AC), CWG is that TS transport streams generate CW by nonlinear pseudorandom sequence generator, and according to 5-10 seconds Cycle constantly update.

3) SK is obtained：Before system operation, front end system will be registered in certificate server.In system operation In, front end system will set up SAC (secure authenticated channel) with certificate server.Dynamically updated based on SAC and business cipher key with Agreement is obtained, front end obtains from certificate server and dynamically updates business cipher key.

4) scramble and encrypt：Scramble and be encrypted as parallel operation.It is embedding to cross copyright and the transport stream TS feeding of legitimacy watermark The software scrambler of hardware independence scrambler or system front end is scrambled.Meanwhile, ECMG is using aes algorithm in business cipher key The CW of each video traffic is encrypted under SK control and obtains ECM.

Front end subsystem is constituted by encapsulating subsystem, pre-packaged subsystem, secure memory subsystem in real time.Encapsulation is sub in real time System is used for the encapsulation of the real-time online of programme content and protection, pre-packaged subsystem be used for offline encapsulation to programme content with Protection.Encapsulation subsystem can select one of them to use or be used in conjunction with as needed with pre-packaged subsystem in real time.Peace Full storage subsystem can select to use as needed.In the case of real-time encapsulation, the ski from Certificate Authority subsystem is (close Key) Mobile state renewal will be entered according to specified time interval, the content after renewal is resend to front end using push mode Subsystem, the business cipher key of front end subsystem is acted on behalf of after PUSH message is received, and is also switched to push- from listening state accordingly Ready (prepares to push) state, after it checked internal state and memory space, and the port specified to Certificate Authority subsystem is sent out Push-ready message is sent, ski transmission process is activated.The feedback of Certificate Authority subsystem is being obtained, is having new sk message to arrive When coming, business cipher key agency is switched to Recv-SKI (reception key) state from listening state, and parsing comes from Certificate Authority subsystem The message of system, extracts ski, stores into the communal space.

For the program transport streams to be encapsulated, first have to obtain transport stream and the business information such as its PSI/SI, passed in capture After PSI/SI packets in defeated stream, Data-process (business scrambling encryption) is from Read-packet (reading package informatin) shape State is switched to Read-PSI (reading PSI) state, and the information such as PSI and SI are analyzed from packet.For pre-packaged process, PSI, SI information immobilize in whole transport stream, therefore only need to undergo a Read-PSI state, for encapsulation in real time Process, PSI, SI information can change in whole transport stream according to the requirement of operator, and accordingly, there exist PSI, SI information The possibility of renewal, at this moment needs that the version of these information is identified, it is necessary to repeatedly undergo Read-PSI states, progress is related The renewal of information.

Referring to Fig. 4, the structure of Certificate Authority subsystem is as follows：Certificate Authority subsystem includes service handling module, business The part such as key SK update module, bidirectional identification protocol, SK agreement protocols, timer, online user's list is constituted.Its effect is Receive application of the user to programme content, business cipher key SK is obtained by certification and negotiation, and periodically carry out key updating.

The main information stream of Certificate Authority subsystem includes：Client certificate (CT), client authorization (CR), business cipher key The ability (KM) with distribution is updated, its moment is in listening state, the client to access carries out CT certifications, and according to specified Time interval Δ t dynamically updates and distribution business cipher key, is receiving the industry from client-end subsystem and front end subsystem Protection information of being engaged in (SPI：Service Protection Information) ask and service authorization information (SAI：Service Authorization Information) request after, respond respectively, perform CR Authorized operations.

Defined according to information flow, the handling function of Certificate Authority subsystem is made up of CT, CR, KM：

Wherein I representative capacities verification function, C represents credit accreditation function, and uid is the identity of user, h_passTo be quiet The cryptographic Hash of state password, cert is user identity certificate, and uid is the identity of user；R represents right described function, and P is represented Right encapsulates function, and sid is the service identification that user uid can be used, and it is basic that rid represents that user uid possesses business sid Right is identified, and cid represents the condition and limitation when right is performed；KD represents business cipher key partition function, and PKG is generation right envelope Fill the handling function of key, y_n-1For the business cipher key at t-1 moment, α, β ∈ { 0,1 } ∧ α ≠ β.

The service handling module of Certificate Authority subsystem is responsible for being opened according to the program application of user as the interface with user Corresponding operation flow is moved, the application and its identity information, credit information under the cooperation of Subscriber Management System to user are carried out Legitimacy and validation verification.For legal, effective application, Certificate Authority subsystem provides key agreement mechanisms and assisted with user Business obtains session key, and session key and its pertinent program information are sent into front end subsystem by safe lane.In addition, Business cipher key is verified and regenerated to identity with fixed intervals again to user by Certificate Authority subsystem.

The service handling module of Certificate Authority subsystem is corresponding with the business application module of client to be interacted, support Business mainly includes：Listing, program request, broadcast etc..

Under program request and broadcasting service, service handling module obtains user related information from Subscriber Management System, by double The identity information of user and the legitimacy and validity of credit information are confirmed to authentication protocol, is then generated by SK agreement protocols The business cipher key SK consistent with user terminal, front end subsystem is sent collectively to user profile, starts programme content scrambled transmission Process.After successful negotiation key, user profile and its corresponding SK will be saved to online user's list, and timer is opened It is dynamic.When reaching specified time interval, (interval provides the minimum interval that re-authentication is consulted, and this is increased with number of users Interval may expand automatically) when, Authentication and Key Agreement is re-started to the user in online user's list by SK update modules, More new session key SK, to improve the security of system.

SK update modules are produced and timing more new business key (SK) and initial vector (IV), and pass through SSL (safety Socket layer) safe lane sends SK to client of the record in online user's list and updates signaling, by ICP/IP protocol to Specify IP and the front end subsystem of port to send the SK data after updating, and ensure the SK data of client and front end subsystem It is completely the same.

The key updating process of Certificate Authority subsystem and client is as follows：(program request)

Certificate Authority subsystem and client are set up after SSL is connected, and pass through SSL safe lane transmitting subscriber informations；

User profile is handled by Subscriber Management System, program request application form is sent to Certificate Authority subsystem by user；

Certificate Authority subsystem utilizes the Pid of program request application form, and corresponding SK is sent to client；

Client receives the information for being masked as SK, analyzes the SK that the information obtains subsequent time；

Peripheral accessory system

Subscriber management system provides user's registration, purchase, inquiry service.Subscriber management system sets up the essential information of user Record, and user resource information record, the mainly record of smart card relevant information, and on this basis record user with The corresponding service condition of smart card.Subscriber management system combination program information management system provides the user ordering interface, receives Registration, the purchase application of user, checking is with identity information (such as set top box numbering, user name, identification card number, public key certificate etc.) Legitimacy, generation user's registration information storehouse and user's ordering information storehouse.User only can not buy in registration, or not only registered but also purchased Buy, or do not register only purchase (but must register in advance).Program Workflow Management System (such as CDN content management server) is right Programme content is managed.Program information management system is classified to the information of program, and provides section to subscriber management system Mesh information.

(1) DVB/IPTV bimodulus interactive service protection system

Referring to Fig. 5, system general module includes：Service protection CAServer servers, empowerment management DRMServer and visitor The part of CAClient modules three in the STB of family end.Wherein CAServer servers correspond to front end subsystem, empowerment management CAClient modules correspondence client-end subsystem in DRMServer correspondence Certificate Authority subsystems, client STB.

CAServer servers include receiving port, sending port, descrambler, the part of key port four.1) scrambler is real In existing CW (control word) generation, ECM (Entitlement Control Message) generation, the analysis of TS streams, the scrambling processes such as ECM multiplexing Whole core contents.2) receiving port realizes that real-time reception specifies the TS program streams of UDP multicast address；3) sending port is realized real When the program TS streams after scrambling multiplexing are forwarded according to specified UDP multicast address；4) key port is realized and DRMServer The interaction of server, and obtain service protection information.

Empowerment management DRMServer includes CA ports, STB ports, certification and url management module, program key management mould Block and control module.1) the business cipher key request of CAServer servers is responsible for receiving in CA ports, and transfers to certification to be taken over chain Manage module to set up after connection, carry out service protection information and update the transmission of service protection information.2) STB ports are responsible for receiving visitor Family end STB service authorization request, and transfer to certification to be set up with url management module after escape way, carry out service authorization information With the transmission for updating service authorization information.3) certification completes DRMServer servers and CAServer clothes with url management module Link between business device is set up and safeguarded, completes to link foundation with safeguarding between DRMServer servers and client STB, Set up and safeguard escape way.4) program key management module is responsible for the generation of service authorization information, updated, and is responsible for mandate Online client STB and CAServer server distribution service authorization message.5) control module is responsible for system module management, and is The concurrent processing of multi-user provides support, supports the extension and performance boost of system.

CAClient modules include descrambler and key port two parts, can also be key-course, business by distinguishing hierarchy Layer, operation layer is core layer, realizes the functions such as registration, service authorization acquisition of information, the descrambling of program of user.1) descramble Device realizes whole core contents in the descrambling procedures such as ECM demultiplexing, analysis, CW decryption, the descrambling of program of TS streams.2) Key port is realized to be interacted with DRMServer servers, submission client STB information, and register user's registration information or Obtain service authorization information.Client STB completes the program that user selects is received, descrambled by CAClient modules, Decoding output.3) client STB is operated according to user and required, the multicast address of selection access respective program.4) client STB will The program received gives CAClient modules, and the decryption to scrambled control word is completed using service authorization information.5) client STB CAClient modules are given by the program received, it is analyzed, descrambled；(5) client STB carries out the program after descrambling Decoding output.

(2) DVB/IPTV bimodulus interactive service protection system is directed to the application of different business pattern

Live (multicast) pattern：

Live (multicast) system groundwork flow：

Start set top box, BOSS systems (business operation support system) connection CA clients, and browse its ordered service row Table, CA clients provide client id and service list by EPG/Portal (electronic program guides/portal technology) to BOSS, Subscribed programmes or request program are played；

CA clients provide client id to authorization server, concurrently send service authorization information to ask；Authorization server leads to Lookup online user's information is crossed, and the certification of client id is carried out between BOSS, service authorization information, BOSS Assets Reorganization Taking is generated Can the account of reason module confirmation user be met needed for ordered program, if can meet, BOSS returns to service to authorization server and awarded Weigh the request results of information；

If by authorizing, transmission instruction is to streaming server, and according to the service list of request, by SS, (stream takes program data stream TS Business device) send, by CA servers, CA servers send service protection information request to authorization server；Authorization server is given Service list generates corresponding system key information and service protection information, and returns to the request of CA server service protection informations As a result；

In CA server ends, TS streams send CA clients to by PSI (program settings information) analyses, scrambling, encryption； CA clients are passed through after the processing opposite with CA server ends, descrambling decryption TS and are sent to screen display.

Authorization server is pushed to CA servers and the Entitlement Control Message interface of CA clients respectively by pushing interface Service protection information, for scrambling and descrambling.

Demand mode：

Program request iCAS system groundwork flows：

Start set top box, BOSS systems connection CA clients, and browse its ordered service list, CA clients pass through EPG/ Portal provides client id and media list to BOSS, and subscribed programmes or request program are played；

CA clients provide client id to authorization server, and send media authorization information request；Authorization server leads to Lookup online user's information is crossed, and the certification of client id is carried out between BOSS, media authorization information, BOSS Assets Reorganization Taking is generated Can the account of reason module confirmation user be met needed for ordered program, if can meet, BOSS returns to media to authorization server and awarded Weigh the request results of information；

If by authorizing, transmission instruction to VOD server, program data stream TS according to the media list of request by VS (depending on Demand service device) send；

Pre-packaged server sends media protection information request to authorization server；Authorization server is generated to media list Corresponding system key information and service protection information, and return to the request results of pre-packaged server media protection information；

In pre-packaged server, TS flows pre-packaged agreement (the pre-packaged agreement according to C/S or B/S working methods：BOSS systems Asset management in system sends the URL after original URL and encryption to pre-packaged server, and to scrambling depth and scrambling mode Deng configuration, pre-packaged server returns to result.) carry out after PSI analyses, scrambling, encryption, send VOD server to；CA client End obtains required content by accessing Web page, and by the processing opposite with pre-packaged server end, descrambling is decrypted after TS and passed It is sent to screen display.

Authorization server is by pushing interface respectively to the Entitlement Control Message interface of preprocessing server and CA clients Media protection information is pushed, for scrambling and descrambling.

(3) the controllable traffic flow security transmission of encryption mode

System scrambling module in the pre-packaged module of front end subsystem uses two kinds of algorithms of CSA and AES, can be according to ring Border needs to change scrambling algorithms in real time.Encrypting module is encrypted using aes algorithm to CW, support CBC (inverse block linking scheme), OFB (output feedback mode), CFB (cipher feedback pattern), CTR (technology mode), five kinds of encryptions of ECB (electronic codebook mode pattern) Entitlement Control Message ECM is encrypted pattern, can arbitrarily be chosen in front terminal system configuration parameter structure, so that Realize the secrecy transmission of information flow.Idiographic flow is as follows.

1)ch_iCan be unity logic channel or single one physical channel to need the program stream for protecting transmission；

2)sk_iFor with program (group) ch_iRelated business cipher key, is produced and is updated by Certificate Authority subsystem controls；

3) P is all sk_iThe set of composition, Q is ch selected by user_iCorresponding sk_iThe subset of composition, and encrypted transmission To user；

4)cw_i ^tTo scramble ch in t_iWhen the control word that uses, length is 64bits (CSA) or 128bits (AES)；

5) S () is to ts_iScramble function, may be selected to be CSA and AES, descrambling key is cw_i ^t(note：S () and S^-1 () selection algorithm should be consistent with key)；

6)S^-1() is to ts_iDescrambling function, may be selected to be CSA and AES, descrambling key is cw_i ^t(note：S () and S^-1() selection algorithm should be consistent with key)；

7)ECM_iFor with ch_iCorresponding Entitlement Control Message, includes cw_i ^tAnd its relevant information；

8) E () is ECM_iGenerating function, is selected as AES, and encryption mode is one of CBC, CFB, OFB, CTR, is encrypted close Key is sk_i(note：D () answers consistent with E () selection algorithm with pattern, key)；

9) D () is ECM_iDecryption function, is selected as AES, and encryption mode is one of CBC, CFB, OFB, CTR, is decrypted close Key is sk_i(note：D () answers consistent with E () selection algorithm with pattern, key).

(4) the service protection level simplified

The system uses double layer encryption strategy, includes two encryptions level, i.e. single-unit mesh relevant layers (PRL:Program Related Layer) and business relevant layers (SRL:Service Related Layer).Implement for PRL layers to be based on cw pairs of control word The scrambling of video content, SRL layers based on business cipher key by encrypting generation business related control information (SRI:Service Related Information), i.e. Entitlement Control Message ECM.Scrambling calls Common Scrambling Algorithm CSA to complete using CW as key Direct scrambling protection to programme content to be transmitted.Encryption calls AES, such as AES using business cipher key SK as key, realizes Encryption to Control Word, forms Entitlement Control Message (ECM).CW ensures the safe transmission of programme content, while CW and SK Separation, also make it that the scrambling of programme content is unrelated with user, reduces the complexity of system.

Entitlement Control Message ECM further is multiplexed to form transport stream with the program stream after scrambling, is distributed by multipling channel To client.Because ECM is related to user, therefore only holds SK user and could descramble, realize the target of Conditional Access. For terminal consumer, some video traffic is accessed if desired, it is necessary to is interacted and is obtained with certificate server by IP duplex channels Obtain the Entitlement Management Message related to consumer.

At PRL layers, video traffic transport stream is scrambled under descrambling key CW control.CW by front end CW makers (CWG) generate, scrambling algorithms are using Common Scrambling Algorithm (CSA) so as to compatible with DVB-CAS.At SRL layers, CW will be close in business Encryption generation ECM under key SK control.And business cipher key SK is then the business application mould by Certificate Authority subsystem and client Block is produced by key agreement protocol.In the transport stream that ECM will be multiplexed to after scrambling.It is complete in the terminals such as consumer's set top box Into opposite process, demultiplex ECM and decryption restoration goes out CW, and then obtain original transport stream and give decoder.With front end phase Together, client will also be obtained from Certificate Authority subsystem and dynamic updates business cipher key sk.

(5) business cipher key updates

The system has used dynamic key to update and distribution technique.Dynamic key updates is divided into two stages with distribution, point It is not that business cipher key switching phase and dynamic service key push the stage.The business application mould of Certificate Authority subsystem and client Block produces business cipher key SK by key agreement protocol.After successful negotiation key, user profile and its corresponding SK will be protected Online user's list is stored to, timer is activated.When reaching specified time interval, (interval provides the minimum that re-authentication is consulted Time interval, may expand automatically with interval of increasing of number of users) when, by SK update modules in online user's list User re-starts Authentication and Key Agreement, more new session key SK, to improve the security of system.Wherein, business cipher key SK It is distributed using modes such as SSL by safe lane.In addition to business cipher key SK, Control Word and system are also included in the system Key MK.The renewal of wherein Control Word is unrelated with user, is updated by appointed interval (such as 10seconds).When discovery industry When business operation goes wrong, system key is just updated, or is carried out more when reaching and specifying time interval (such as 1month) Newly.

System has been respectively adopted cipher key hierarchy update method and improved group close during business cipher key is updated Key update method.So-called cipher key hierarchy updates, be exactly DRM authorization Verification System when carrying out key updating, upper level DRM Server only carries out key updating to the DRM Server in local area, and without directly providing service to user, and improved group close The characteristics of key agreement, allows for the specific business characteristic of television services, and broadcasting service and other value-added services are carried out into difference pair Treat, if user has had subscribed to the broadcasting service specified, then when switching uses other business, DRM system is not to broadcast Business cipher key updates, and key updating processing is only carried out to value-added service, and find group key more during key updating New minimum nodes, communication overhead and computing capability loss that further reduction business cipher key updates.

The key updating process of Certificate Authority subsystem and front end subsystem is as follows：Certificate Authority subsystem and front end subsystem TCP/IP connections are stood in construction in a systematic way, open the network monitoring of front end subsystem, and the message that Certificate Authority subsystem is sent is carried out in real time Analysis；Certificate Authority subsystem sends the SK information updated in predetermined time interval；Front end subsystem receives Certificate Authority After the message flag that subsystem is sent is SK information, the information is analyzed.Current SK is verified and extracted The SK data that next moment uses.Then confirmation is sent to Certificate Authority subsystem.Complete Certificate Authority subsystem with The key updating of front end subsystem.

The key updating process (broadcast) of Certificate Authority subsystem and client is as follows：Certificate Authority subsystem and client Set up after SSL connections, pass through SSL safe lane transmitting subscriber informations；Certificate Authority subsystem is obtained according to online user's list After user's program Pid and user profile, notify whether SSL is transferred to customer service key, and its program Pid；Client terminates The information for being masked as SK is received, is saved backup.

The key updating process (program request) of Certificate Authority subsystem and client is as follows：Certificate Authority subsystem and client Set up after SSL connections, pass through SSL safe lane transmitting subscriber informations；User profile is handled by Subscriber Management System, user is by point Broadcast application form and be sent to Certificate Authority subsystem；Certificate Authority subsystem utilizes the Pid of program request application form, and phase is sent to client The SK answered；Client receives the information for being masked as SK, analyzes the SK that the information obtains subsequent time.

(6) the pre-packaged technology based on agency

With reference to Fig. 6, the system model uses C/S structures, as shown in the figure.The pre-packaged system end on the right side is server, depending on Frequency input is client.C/S model is also used in pre-packaged internal system, is made up of master server and proxy server, is acted on behalf of Server is server end for master server, and master server is client.

Entirely the design philosophy of model is：To needing to encapsulate the video encrypted, master server is initially entered, it is according to video Size is judged, chooses whether to need proxy server to encapsulate.If being not required to agency to perform, do not split video file, oneself Directly it is packaged encryption；If desired agency performs, then video file is divided into several segments according to the algorithm of design, then certainly Idle proxy server on dynamic search network, sends the video being segmented to available agency, allows its execute encapsulation function. After proxy server encapsulation is completed, then main server-side is returned in time, weighed the segmentation of return by main server-side Group, reverts to complete packaged " former video " file.

Proxy server mainly includes pre-packaged main control module and pre-packaged proxy module.According to pre-packaged main control module Function can be classified as two parts：A part is central controller, and main realize acts on behalf of encapsulation operation to video file, such as divides Cut, dispatch with merging；Another part is independent pre-packaged module, i.e., without using proxy server, and directly video content is completed Encapsulation function.

Pre-packaged technical method based on agency mainly includes Video segmentation, and video dispatching and key are obtained.

Video segmentation is for the video for needing to encapsulate, if its size is m (mb), need to split hop count for s, video encapsulation Speed is k (mb/s), and the speed of transmission of video is v (mb/s), and Video segmentation needs duration t1, and video merging takes a length of t2.In specific implementation procedure, carry out according to the following rules：One section of segmentation, transmits one section；While transmission, to carry out in real time Encapsulation；It is transmitted back at once after the completion of video-frequency band encapsulation；Pass several sections back, then merge several sections.The hop count s that should split should meet public affairs Formula：Δt₁+Δt₂·s+2(m/s)/v+(m/s)/k<M/k, wherein, m/k is the independent pre-packaged required time.

TS video files are made up of the TS bags of multiple 188 bytes, therefore when size and the segmentation video part of segmentation video Required buffer size should be the integral multiple of 188 bytes.If the video size of input is ten thousand TS bags of n, split thought For：

(1)n<When=160, video is not split；

(2)160<n<When=320, Video segmentation is 2 sections；

(3)320<n<When=480, Video segmentation is 3 sections；

(4)480<n<When=640, Video segmentation is 4 sections；

(5)n>When 640, Video segmentation is 5 sections.

Video dispatching mainly realizes main control module selection proxy module and is allowed to complete pre-packaged process, idiographic flow For：Pre-packaged main control module regularly sends broadcast message after starting, after the pre-packaged proxy module of line receives broadcast message, Confirmation is sent to pre-packaged main control module end, the situation of each pre-packaged proxy module is saved in number by pre-packaged main control module According in storehouse.After pre-packaged main control module end request agency, just start to transmit video, the relevant information of video transmission can be saved to Corresponding journal file (including the agent identification that is transferred to of video name, video delivery time, video etc.) in.Work as video segmentation Number less than respond when acting on behalf of number, it is necessary to randomly choose it is therein it is several act on behalf of execute encapsulation process, detailed process is：1) it will receive The identity map of the agency arrived is the integer between 1-100 (assuming that agency's sum<=100)；2) according to the dividing number of video, It is determined that what is needed acts on behalf of number n；3) the n numbers between 1-100 are produced using pseudorandom number generator；4) according to the random number of generation Corresponding agent identification is found, the final encapsulation agency for determining to need.

Key obtains the acquisition for including the pre-packaged service key of front terminal System Subsystem and client-end subsystem is pre-packaged Key is obtained.The acquisition flow of the pre-packaged service key of front terminal System Subsystem is：(data base administration takes video content DBMS Be engaged in device) according to Mlist (media list) to pre-packaged main control module send transport stream, pre-packaged main control module give Certificate Authority The Certificate Authority module of system sends MPI (media protection information) request；Certificate Authority module sets up MKI (media keys Information), MPI is generated, database is arrived into MKI storages, and using Mlist as index；Certificate Authority module returns to pre-packaged master control Module MPI request results；Pre-packaged master control mould is after calling agency's completion pre-packaged, by TS transmission back to DBMS.Client child The pre-packaged key of system obtains flow：Start after set top box, client receives packaged from video server Video content；Client-end subsystem provides client identification and from transmission of video to the Certificate Authority module of Certificate Authority subsystem The media list Mlist obtained in stream, sends MAI requests；Certificate Authority module carries out client mark with subscriber management intermodule The certification of knowledge, subscriber management module returns to the media list Mlist ' that can be authorized for user to Certificate Authority module, according to number MAI is generated according to the Mlist ' information in storehouse；Certificate Authority module returns to client-end subsystem MAI request results；Client child System can descramble and watching video content.

The system supports off-line data processing, can be with when pre-packaged system server needs to close or interrupts service Central controller is first passed through, proxy server is selected, after video transmission, that is, service is closed or interrupt.When pre-packaged system After the service of server is again turned on, agent side automatically can send video, and server need to only carry out later operation can With.Furthermore it is also possible to mitigate master server burden, realize that high efficiency is encapsulated.When video needs encapsulation all the way, if using generation Server help is managed, processing time can be reduced；When multi-channel video needs scrambling, server end, due to the limitation of operational capability The scrambling work of many data volumes is completed, excessive burden can be brought to server, the efficiency of encapsulation is influenceed.And if regarded multiple Frequency gives the work that proxy server is packaged according to being handled, then, can so accelerate the efficiency of encapsulation, mitigates service The burden at device end.The quantity of proxy server determines the number of video segmentation, and proxy server is more, and the segments of video is got over It is many.The hop count of video point is more, will reduce the data volume that each video-frequency band is included, so on the one hand can further subtract Few transmission time, on the other hand, can also tail off, so that on the whole the time required to the encapsulation video-frequency band on all proxy servers Improve operating efficiency.

Distributed pre-packaged system, if under high performance network environment, will be more advantageous.The transmission of video file can By means of the more quick transmission medium such as high bandwidth network or optical fiber, video file to be carried out to send in real time with receiving. Because the transmission speed of the transmission mediums such as optical fiber is very fast, in terms of multiple video segmentation transmission, the long time will not be taken, because And the efficiency of whole system can be improved.

(7) safety storage

Memory space ergodic algorithm of the system based on random process realizes safe storage.System design key point Hair center (Key Distribution Center, KDC) to provide business cipher key for the encryption and decryption file of client, and KDC is first obtained The segmentation situation (such as n subfile) of client cryptograph files is obtained, corresponding 1 to n unduplicated random sequence, client is generated End sends ciphertext subfile to storage server successively according to random sequence；Storage server sets up new file, close by what is received Literary subfile writes new file, until ciphertext subfile is sent；So, out of order ciphertext is just incorporated in storage server File, file is uploaded successfully.When file is downloaded in user's application, storage server obtains file path, finds file, will disorderly The cryptograph files of sequence directly transmit client, and the secure decryption of data is directly completed in client, and protection file adds end to end Close transmission and the safety storage of data.

(8) selectivity scrambling is deep-controlled

The system is more accurately controlled to realize to scrambling depth, uses new to the method for counting of I frames and I- macro blocks Double upper limits count (n1, n2) method so that count upper-limit n values all can use and arbitrarily scramble depth d can select.To appointing The d of meaning, if：1) 1/d is integer, then makes n1=1/d, n2=1；2) 1/d is not integer, then 1/d is expressed as into fraction, is used in combination Euclidean algorithm obtains the greatest common divisor r of molecule denominator, and 1/d=a/b, order are about obtained afterwards：Wherein a and b are Mutual prime rwmber.

To I frame count c1, the c2 found, when c1 reaches upper limit n1, Scrambling Operation is performed to present frame；On c2 reaches When limiting n2, two counters are all reset, c1=c2=0.

The set-up mode of two kinds of scrambling depth is provided in actual applications：1) n modes are set, and n is the scrambling upper limit, is actually set It is 1/n to put scrambling depth；2) d modes are set, and d is scrambling depth, and scrambling upper limit n values are true using above-mentioned double upper limit method of counting It is fixed.

(9) key updating batch processing strategy

System design introduces key updating batch processing strategy there is provided the key real-time update of million userbases and distribution, Overhead is reduced, the ability of whole key updating is enhanced, the security of system is improved, provided for pay TV business Flexible and changeable protection mechanism.This cipher key management structure proposed include authorization server (AS, Authentication Server) and multiple key servers (KS, Key Server) the two major parts.Authorization service Device manages all users of indirect control as tree root, the key message of distribution service protection by key server.

Authorization server, it includes user authentication module, key server module and user's authorization module.It acts on bag Include the access (leaving) for receiving user by SSL safe lanes to ask, and authentication is carried out to user；In the event of grant set Member changes, and the key server management module of authorization center obtains each key server module by SSL safe lanes and produced Raw demand (telecommunication) service key simultaneously calculates broadcasting service cryptographic key by one-way function, while notifying demand (telecommunication) service key server more Its new sub- grant set broadcast (program request) business cipher key, undertakes the key tree that authorization server is constituted with each program request key server Foundation and maintenance work；Authoring system scrambles server by ES (Encryption System) interfaces and front end and controlled Word descrambling key information exchange processed, adds so that the multicast key of each key server be sent to as control word descrambling key Disturb server；Authorization server carries out interacting for user profile with Subscriber Management System, is signed and issued by authorization center and is based on x.509 marking Accurate digital certificate.The certificate is used for authorized user and carries out authentication when application adds grant set.

Key server, including key production module, key distribution module and key management module.Its function includes logical Cross key production module and produce pseudo random number, be used as demand (telecommunication) service key to be distributed；Realized by key distribution module for awarding Weigh the group key distribution of group membership；Key management module carries out data interaction with authorization server, sends and adds in authorization server Plus (deletion) mandatory member instruction when, key management module notifies key production module to produce new demand (telecommunication) service key, so The program request key after renewal is sent to authorization server by key management module afterwards, and by key distribution module to specified User key node carries out key updating.

Referring to Fig. 7, it is assumed that u3 and u4 are the users of two sub- grant sets of application transfer.U3 is transferred to B groups from A groups, and u4 is from B Group is transferred to A groups.U4 substituted for the original positions of u3, and u3 substituted for original u4 position.It is K to need the cipher key node updated_A And K_B.Key updating path is determined, only need to be during each update, we track the section of each needs more new key Point, the node for needing more new key to its upper level is marked.In this process, if it find that there is a node to be labeled Then stop the mark in the path twice.Until all path tags are finished, key updating path is determined that.In whole key tree In, only K_A' and K_B' need to update.K_ADemand (telecommunication) service key updating is K_A', K_BDemand (telecommunication) service key updating is K_B’.Program request industry Business key server A is sent to u1, is sent, is sent to u4 to u2.Demand (telecommunication) service key server B is sent to u3, is sent to u5, Sent to u6.

Claims (12)

1. a kind of DVB/IPTV bimodulus interactive service protects system, it is characterised in that：The system includes client-end subsystem, front end Subsystem, Certificate Authority subsystem, subscriber management system, program Workflow Management System, program information management system part, wherein visitor Family terminal system, front end subsystem, Certificate Authority subsystem are major part, subscriber management system, program Workflow Management System, section Mesh information management system is peripheral accessory system, DVB/IPTV bimodulus interactive service protection system, including service protection The part of module of CAClient tri- in CAServer servers, empowerment management DRMServer and client STB, wherein In CAServer servers correspondence front end subsystem, empowerment management DRMServer correspondence Certificate Authority subsystems, client STB CAClient modules correspondence client-end subsystem；

Wherein, described front end subsystem includes：Control word generator (CWG), ECM makers (ECMG), watermarking algorithm And Common Scrambling Algorithm (CSA) (WEA)；The effect of front end subsystem is generation control word, calls Common Scrambling Algorithm (CSA) right Programme content from program Workflow Management System is scrambled；The control word generator of front end subsystem is based on system key Control word is generated, scrambling behaviour is carried out to the programme content from program Workflow Management System using DVB Common Scrambling Algorithms (CSA) Make；Front end subsystem is also encrypted to control word using session key and generates traditional ECM simultaneously；Programme content after scrambling Program distribution system, which is passed to, with ECM carries out multiplexing transmission；Front end subsystem will regenerate scrambled control word with fixed intervals, Ensure the transmission safety of programme content；Under program request interactive mode, front end subsystem also is responsible for receiving the broadcasting control of user simultaneously Information processed, and being adjusted to scrambling and program streaming, described front end subsystem further by encapsulating subsystem in real time, it is pre- Encapsulate subsystem, secure memory subsystem to constitute, subsystem is encapsulated in real time for the real-time online encapsulation to programme content with protecting Shield, pre-packaged subsystem is used for offline encapsulation and protection to programme content, and encapsulation subsystem can with pre-packaged subsystem in real time To select one of them to use or be used in conjunction with as needed, secure memory subsystem can select to use as needed.

2. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：Client, which is used, divides Layer and modular structure, client are divided into interface layer, key-course and operation layer from top to bottom；The task that interface layer provides standard connects Mouthful, receive customer service instruction and user profile, interface layer to user feedback system implementing result or descrambling after programme content； Key-course is responsible for business module list, calls corresponding operation layer module to complete corresponding business, association according to service order The operation of each business module is adjusted there is provided the data exchange mechanism of each business module, and compiles the implementing result of each industry module Feed back to interface layer；Operation layer includes multiple business modules：Order module, business application module, business acquisition module；Order mould Block completes registration, purchase, query function；Business application module completes programme application, program request application, broadcast application, live Shen Please, arranging key function；Business acquisition module completes demultiplexing, decryption ECM, descrambled program stream, the checking legal sexual function of program； Wherein, demultiplexing function is synchronous with the foundation of front end subsystem using odd even control word mode in tradition DVB-CA systems, and receive, Demultiplexing, obtains ECM and program stream；Decryption ECM functions ECM are decrypted acquisition descrambling control using the session key of negotiation Word CW；The Control Word that descrambled program stream function is obtained using decryption calls AES or CSA Descrambling Algorithms to solve program stream Disturb, obtained DVB/IPTV programs are streaming to key-course；The legal sexual function of checking program is used to extract the conjunction in program stream Method identifies watermark.

3. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：Described certification is awarded Subsystem is weighed by service handling module, business cipher key SK update modules, bidirectional identification protocol, SK agreement protocols, timer, online User list part is constituted, and Certificate Authority subsystem receives application of the user to programme content, industry is obtained by certification and negotiation Business key SK, and key updating is periodically carried out, the service handling module of Certificate Authority subsystem is the interface with user, root Start corresponding operation flow, the application to user and its identity under the cooperation of Subscriber Management System according to the program application of user Information, credit information carry out legitimacy and validation verification, and for legal, effective application, Certificate Authority subsystem provides close Key negotiation mechanism consults to obtain session key with user, and session key and its pertinent program information are sent by safe lane Front end subsystem is given, business is verified and regenerated to the identity with fixed intervals again to user by Certificate Authority subsystem Key.

4. a kind of DVB/IPTV bimodulus interactive service protection system according to claim 1, it is characterised in that：Described CAServer servers include receiving port, sending port, scrambler, the part of key port four；Described empowerment management DRMServer includes CA ports, STB ports, certification and url management module, program key management module and control module；Institute The CAClient modules stated include descrambler and key port two parts, are key-course, operation layer by distinguishing hierarchy, and operation layer is Core layer, realizes the registration of user, service authorization acquisition of information, the descrambling function of program.

5. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：The system design KDC (Key Distribution Center, KDC) provide business cipher key for the encryption and decryption file of client, close Key Distribution Center first obtains the segmentation situation of client cryptograph files, when for n subfile, and generation corresponding 1 to n is not repeated Random sequence, client according to random sequence successively to storage server send ciphertext subfile；Storage server is set up new File, new file is write by the ciphertext subfile received, until ciphertext subfile is sent.

6. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：The system uses Controllable scrambling depth-size strategy and adaptive scrambling technology, are dynamically adjusted according to carrier network situation, different compressed encodings and code check Whole scrambling parameter, can reduce data processing amount while the business of protection, reduce the scrambling expense of video, and the system is real Now to the control of scrambling depth, the method that (n1, n2) is counted using double upper limits to the method for counting of I frames and I- macro blocks so that meter Number upper limit n values all be can use and any scrambling depth d can be selected；To arbitrary d, if：1) 1/d is integer, then makes n1= 1/d, n2=1；2) 1/d is not integer, then 1/d is expressed as into fraction, and obtains with Euclidean algorithm the maximum of molecule denominator Common divisor r, about obtains 1/d=a/b, order afterwards：Wherein a and b are mutual prime rwmbers；

To I frame count c1, the c2 found, when c1 reaches upper limit n1, Scrambling Operation is performed to present frame；When c2 reaches upper limit n2 When, two counters are all reset, c1=c2=0；

The set-up mode of two kinds of scrambling depth is provided in the application：1) n modes are set, and n is the scrambling upper limit, and actual setting scrambling is deep Spend for 1/n；2) d modes are set, and d is scrambling depth, and scrambling upper limit n values are determined using above-mentioned double upper limit method of counting.

7. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：The system is to high definition The efficiency that interactive large scale programme content is packaged, the distributed pre-packaged technology based on intelligent agent, passes through intelligence Segmentation, scheduling, the collaboration of change, on the premise of security and uniformity is ensured, improve the pre- envelope to large scale programme content Speed is filled, system model uses C/S structures, and pre-packaged system end is server, and video input is client, in pre-packaged system It is internal also to use C/S model, it is made up of master server and proxy server, proxy server is server for master server End, master server is client；To needing to encapsulate the video encrypted, master server is initially entered, master server is big according to video It is small to be judged, choose whether to need proxy server to encapsulate；If being not required to agency to perform, do not split video file, main service Device is directly packaged encryption；If desired agency performs, then video file is divided into several segments according to the algorithm of design, then Idle proxy server on automatic search network, sends the video being segmented to available agency, allows its execute encapsulation work( Energy；After proxy server encapsulation is completed, then main server-side is returned in time, carried out the segmentation of return by main server-side Restructuring, reverts to complete packaged " former video " file.

8. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：The system is used Dynamic key updates and distribution technique；Dynamic key updates is divided into two stages with distribution, is business cipher key switching phase respectively The stage is pushed with dynamic service key；The business application module of Certificate Authority subsystem and client is produced by key agreement protocol Occupation business key SK；After successful negotiation key, user profile and its corresponding business cipher key SK will be saved to online user List, timer is activated；When reaching specified time interval, by business cipher key SK update modules in online user's list User re-starts Authentication and Key Agreement, more new session key SK, wherein, business cipher key SK passes through safety using SSL modes Channel is distributed；In addition to business cipher key SK, Control Word and system key MK are also included in the system；Wherein Control Word Update unrelated with user, be updated by appointed interval.

9. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：System is updating industry It is engaged in during key, cipher key hierarchy being respectively adopted and has updated and group key management；Described cipher key hierarchy is updated, i.e., DRM is awarded Verification System is weighed when carrying out key updating, upper level DRM Server only carry out key more to the DRM Server in local area Newly, without directly providing user service, and group key management is to be treated with a certain discrimination broadcasting service and other value-added services, If user has had subscribed to the broadcasting service specified, then when switching uses other business, DRM authorization Verification System is not right Broadcasting service cryptographic key is updated, and only carries out key updating processing to value-added service, and group key is found more during key updating New minimum nodes.

10. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：The system is preceding Scrambling module uses two kinds of algorithms of CSA and AES in the pre-packaged module of terminal system, needs to change to scramble in real time according to environment to calculate Method, encrypting module is encrypted using aes algorithm to CW, supports CBC (inverse block linking scheme), OFB (output feedback mode), CFB (cipher feedback pattern), CTR (technology mode), five kinds of encryption modes of ECB (electronic codebook mode pattern) are to Entitlement Control Message ECM It is encrypted, is arbitrarily chosen in front terminal system configuration parameter structure, realize the secrecy transmission of information flow.

11. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that：The system is used Double layer encryption strategy, includes two encryptions level, i.e. single-unit mesh relevant layers (PRL:Program Related Layer) and business Relevant layers (SRL:Service Related Layer), scrambling of the PRL layers of implementation based on Control Word to video content, SRL layers Based on business cipher key by encrypting generation business related control information (SRI:Service Related Information), i.e., Entitlement Control Message ECM, is scrambled using Control Word as key, calls Common Scrambling Algorithm CSA to complete to programme content to be transmitted Direct scrambling protection, encrypt using business cipher key SK as key, call AES, the encryption to Control Word, formed authorize Control information (ECM), Control Word ensures the safe transmission of programme content, while the separation of Control Word and business cipher key SK, Also so that the scrambling of programme content is unrelated with user, the complexity of system is reduced.

12. DVB/IPTV bimodulus interactive service according to claim 1 protects system, it is characterised in that the system is introduced Key updating batch processing strategy, makes key real-time update and the distribution of million userbases, it includes an authorization server (AS, Authentication Server) and two parts of multiple key servers (KS, Key Server), wherein authorizing clothes Device be engaged in as tree root, the key message of distribution service protection, and all users of indirect control are managed by key server；Authorize Server, including user authentication module, key server module and user's authorization module, authorization server pass through SSL safety Channel receives the access of user or leaves request, and carries out authentication to user；Key server, including key generation mould Block, key distribution module and key management module, key server produce pseudo random number by key production module, as treating The demand (telecommunication) service key of distribution；Group key distribution for authorizing group membership is realized by key distribution module；Key management module Data interaction is carried out with authorization server, when authorization server sends addition or deletes the instruction of mandatory member, key management Module notifies key production module to produce new demand (telecommunication) service key, and then key management module is close by the program request after renewal Key is sent to authorization server, and carries out key updating to specified user key node by key distribution module.