CN101267639B - a memory card - Google Patents

Abstract

The invention discloses a memory card, realizes condition reception of a mobile terminal via a general memory card interface, such as SD/MMC, by using a condition reception unit as a composing part of the memory card, performs set/card separation condition reception of mobile terminal digital television services, is convenient for development of the mobile terminal digital television services, largely reduces modification cost of the mobile terminal, such as a handset. Further, the invention discloses a method for a memory card realizing condition reception, which realizes the mobile terminal digital television services and saves cost.

Description

a memory card

technical field

The invention relates to storage technology, in particular to a storage card. the

Background technique

At present, there are mainly two ways to realize conditional reception of digital TV services on mobile terminals (such as mobile phones or other terminals):

One method is realized through the mobile communication network, usually by means of streaming media, using the SIM card controlled by the mobile operator for authentication and conditional access. China Mobile and China Unicom have already launched mobile digital TV services in this way , but this method has the problem of high cost and unacceptable by users;

Another method is realized through satellite or terrestrial broadcasting. This method requires a built-in chip or an external conditional access card in the mobile terminal to achieve conditional access and descrambling. The biggest advantage of this method is that the transmission cost is low and can be predicted , this way is a new choice for digital TV operators and users. However, digital TV operators usually hope to adopt multiple CA manufacturers to avoid being monopolized by a certain CA manufacturer. And this approach is very unfavorable for mobile terminal manufacturers, making mobile terminal manufacturers have to produce a variety of motherboards, and the production volume is small, there are many types, the cost is greatly increased, and the standards adopted by various digital TV operators are different. This makes mobile terminal manufacturers provide conditional access cards with different standard interfaces to meet corresponding requirements. In this way, the cost of TV operators and mobile terminal manufacturers has also increased, which will undoubtedly directly damage the interests of end users. To sum up, an obvious disadvantage of this method is that it is impossible to separate the machine card, which brings a series of problems. the

At present, my country's corresponding technical research and product development based on the method of implementing conditional access with a built-in chip or an external conditional access card in the mobile terminal is in the active development stage, and there is no specific implementation plan yet. the

Contents of the invention

In view of this, the purpose of the embodiment of the present invention is to provide a memory card, which can realize the digital TV service of the mobile terminal, realize the separation of the machine and the card, and save costs. the

In order to achieve the above object, the technical solution of the embodiment of the present invention is specifically implemented as follows:

A memory card, the memory card includes: a memory card control unit, a conditional access unit, a storage unit, and a memory card interface, wherein,

The memory card control unit is used to control the memory card interface to send and receive data and perform protocol analysis, manage the storage unit, and coordinate the work of each unit in the memory card;

The memory card interface is used to receive data from the outside and store it in the storage unit under the control of the memory card control unit; the external data includes the first information flow, the second information flow and scrambling information;

The conditional receiving unit, under the control of the memory card control unit, acquires the first information flow, the second information flow and the scrambling information, and judges according to the second information flow that the mobile terminal to which it belongs has the service use authority for the scrambling information, according to The second information flow obtains the corresponding service key, uses the service key to decrypt the ciphertext control word in the first information flow and obtains the plaintext control word; under the control of the plaintext control word, descrambles the scrambled information to obtain Obtain the business data flow required by mobile terminal users. the

The conditional access unit includes: authority control module, service key extraction module, control word extraction module, descrambling module, file management module and key management module, wherein,

The authority control module sends an authentication success notification to the service key extraction module when the service identifier in the received second information flow is the same as the service identifier corresponding to the conditional access service supported by the user terminal pre-stored in the file management module , and send the second information flow to the service key extraction module; when the received service identifier is different from the stored one, exit the currently triggered conditional access service;

The service key extraction module receives the authentication success notification, and according to the received key seed ID number in the second information stream, when the service key corresponding to the key seed ID number is stored in the key management module, Extract the corresponding service key from the key management module according to the key seed ID number, and send the extracted service key to the control word extraction module; when the key seed ID number in the second information stream changes, update The corresponding service key ID number in the memory card;

The control word extraction module obtains the first information flow from the authority control module, and obtains the ciphertext control word from the first information flow, and uses the service key from the service key extraction module to decrypt the ciphertext control word to obtain the plaintext Control word, and sent to the descrambling module;

The descrambling module is used to obtain scrambled data from the storage unit under the control of the memory card control unit, and use the plaintext control word from the control word extraction module to descramble the scrambled data, and descramble the descrambled data Send it to the terminal through the memory card interface. the

The protocol of the memory card interface is a digital security memory card or MMC universal interface standard protocol. the

The memory card control unit is connected to the conditional receiving unit through a data line to request to send a data signal, to be ready to receive/send a data signal, to request to receive a data signal, and to be connected to a data latch clock signal. the

It can be seen from the above-mentioned technical solution that the embodiment of the present invention realizes conditional reception at the mobile terminal through a universal memory card interface such as SD/MMC by using the conditional access unit as a component of the memory card, and achieves a mobile terminal digital TV service implementation mechanism. The conditional access of card separation facilitates the development of mobile terminal digital TV services and greatly reduces the cost of transformation of mobile terminals such as mobile phones. the

Description of drawings

Fig. 1 is the composition structure schematic diagram of memory card of the present invention;

Fig. 2 is a schematic diagram of the composition structure of the conditional access unit of the present invention;

Fig. 3 is the flow chart that the present invention realizes conditional access;

Fig. 4 is a schematic diagram of an embodiment of the connection between the conditional interface unit and the memory card interface unit of the present invention;

Fig. 5 a is the timing diagram of the memory card control unit of the present invention sending data to the conditional receiving unit;

Fig. 5b is a timing diagram of the memory card control unit receiving data from the conditional access unit. the

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. the

FIG. 1 is a schematic diagram of the composition and structure of the memory card of the present invention. As shown in FIG. in,

The memory card control unit 100 is used to control the memory card interface 103 to send and receive data and perform protocol analysis, manage the storage unit 102, and coordinate the work of each unit in the memory card. the

Memory card interface 103: used to receive data from the outside, such as the data that the user needs to store, the first information stream, the second information stream, and scrambled information related to digital streams such as audio and video, such as digital TV signals, and store them It is stored in the storage unit 102 under the control of the card control unit 100 . The protocol of the memory card interface 103 may be a general interface standard protocol such as a digital secure memory card (SD card)/MMC, but is not limited to any interface method. the

Among them, the first information stream mainly includes Entitlement Control Messages: such as ciphertext control words, time information, etc.;

The second information flow mainly includes Entitlement Management Messages: such as business identification, key seed ID number, time information, etc.;

The scrambled information is scrambled video and audio signals such as digital television signals. the

Storage unit 102: for storing data sent to the memory card, which may be FLASH, EEPROM, ROM, etc. the

Conditional access unit 101: used for descrambling scrambled information such as audio and video data streams, and user management, where user management includes functions such as authority control and key management. Under the control of the memory card control unit 100, the first information stream, the second information stream and the scrambling information are acquired, and after judging from the second information stream that the mobile terminal to which the mobile terminal belongs has the service use authority for the scrambling information, then according to the second information stream The second information flow obtains the corresponding service key, uses the service key to decrypt the ciphertext control word in the first information flow and obtains the plaintext control word, and finally under the control of the control word, descrambles the scrambled information to obtain The business data flow required by mobile terminal users. the

Whether conditional access is required is selected by the user through the terminal, and when the user makes a selection, the memory card control unit 100 will be triggered to process the conditional access. The selection of the conditional access and the process of triggering the memory card control unit 100 on the conditional access belong to the prior art and will not be repeated here. What the present invention emphasizes is that the conditional access unit is used as a component of the memory card, so that the conditional access is realized in the mobile terminal through the universal memory card interface such as SD/MMC, and the condition for separating the machine card from the digital TV service of the mobile terminal is realized Reception facilitates the development of mobile terminal digital TV services and greatly reduces the cost of transformation of mobile terminals such as mobile phones. the

It should be noted that the composition structure of the memory card shown in FIG. 1 only involves units related to conditional access, and other existing units are not shown in FIG. 1 . the

FIG. 2 is a schematic diagram of the composition and structure of the conditional access unit of the present invention. The working principle of the conditional access unit will be described in detail below. As shown in FIG. 2 , the conditional access unit 101 includes: an authority control module 1011 , a service key extraction module 1012 , a control word extraction module 1013 , a descrambling module 1014 , a file management module 1015 and a key management module 1016 . When the user triggers the conditional access service, the work of each component module in the conditional access unit includes:

The authority control module 1011 is configured to obtain the first information flow and the second information flow, and according to the service identification in the second information flow, and the service identification corresponding to the conditional access service supported by the user terminal pre-stored in the file management module 1015 , to determine whether the memory card has the authority to receive services using the currently triggered conditions, if the received service identifier is the same as the stored one, then send an authentication success notification to the service key extraction module 1012, and send the second information flow to Service key extraction module 1012; if the received service identifier is different from the stored one, exit the currently triggered conditional access service, such as displaying to the user through the terminal that there is no right to use the current service. the

Here, the acquisition of the first information stream and the second information stream is obtained from the storage unit 102 under the control of the memory card control unit 100 and then transmitted to the authority control module 1011. There are many specific acquisition methods, which belong to those skilled in the art. Conventional technical means are not described in detail here. the

The service key extraction module 1012 receives the authentication success notification, and checks whether the service key corresponding to the key seed ID number exists in the key management module 1017 according to the key seed ID number in the received second information flow. If it exists, extract the corresponding service key from the key management module 1016 according to the key seed ID number, and send the extracted service key to the control word extraction module 1013. When the key seed ID number in the second information stream changes, the corresponding service key ID number in the memory card is updated. It is explained here that the key seed ID number is called the service key ID number in the memory card. the

It should be noted that the one-to-one correspondence between key seed ID numbers and service keys is pre-stored in the key management module 1016 . the

The control word extraction module 1013 obtains the first information flow from the authority control module 1011, and obtains the ciphertext control word from the first information flow, and uses the service key from the service key extraction module 1012 to decrypt the ciphertext control word , to obtain the plaintext control word and send it to the descrambling module 1015. the

The descrambling module 1014, under the control of the memory card control unit 100, obtains the scrambled data from the storage unit 102, and uses the plaintext control word from the control word extraction module 1013 to descramble the scrambled data, and finally descrambles the descrambled data The final data is sent to the terminal through the memory card interface 105. The specific implementation of descrambling belongs to the technology known to those skilled in the art, and is not the focus of the present invention, so it will not be repeated here. the

It should be noted that the descrambling module 1014 can be an integral part of the memory card, as shown in Figure 2, since the descrambling is completed in the memory card, all keys are not out of the memory card, which improves the security of the conditional access system , while reducing the performance overhead of the mobile terminal;

The descrambling module 1014 can also be independent from the memory card, such as in the security algorithm chip, because there is a CPU in the security algorithm chip, so the descrambling speed of the terminal can be further improved. When the descrambling module 1014 is set in the security algorithm chip, under the control of the memory card control unit 100, the scrambled data is obtained from the storage unit 102, and the plaintext control word is obtained from the control word extraction module 1013, and is passed through the memory card interface 105 Send the scrambled data and plaintext control word to the security algorithm chip. the

After receiving the data, the descrambling module performs descrambling processing, and the descrambled data is sent to the terminal through the memory card interface 105 . The descrambling algorithm can be implemented by using the anti-encryption algorithm of the front-end processor, which belongs to the prior art and will not be described in detail here. the

Fig. 3 is a flow chart of the present invention to realize conditional access. When the user selects and selects the conditional access service through the terminal, the memory card is triggered to process the conditional access, which mainly includes the following steps:

Step 300: Determine whether you have the right to receive services using the currently triggered conditions, if yes, go to step 301; otherwise, go to step 304. the

After the user selects the conditional access service through the terminal, the memory card will receive external conditional access service data, such as the data that the user needs to store, the first information stream, the second information stream and the Scrambling information, etc., wherein the first information flow mainly includes authorization control information: such as ciphertext control words, time information, etc.; the second information flow mainly includes authorization management information: such as business identification, key seed ID number, time information, etc. ; The scrambled information is a scrambled video and audio signal such as a digital television signal. the

If the service identifier carried in the received second information flow is the same as that stored in the memory card, it indicates that the memory card has the right to use the currently triggered condition to receive the service. the

Step 301: Determine whether there is a service key corresponding to the currently triggered conditional access service, if yes, go to step 302; otherwise go to step 304. the

According to the key seed ID number in the second information flow received, query whether the service key corresponding to the key seed ID number is stored in the memory card, and if there is, determine that there is a service key corresponding to the currently triggered conditional access service key. When the key seed ID number in the second information stream changes, the corresponding service key ID number in the memory card is updated. the

Step 302: Use the corresponding service key to decrypt the ciphertext control word to obtain the plaintext control word. the

The ciphertext control word is carried in the first information flow. There are many decryption methods in this step, such as the existing AES CTR and AES ECB, etc., which will not be described in detail here. the

Step 303: Use the obtained plaintext control word to descramble the scrambled information to obtain conditional access service data. the

The specific implementation of descrambling belongs to the technology known to those skilled in the art, and is not the focus of the present invention, so it will not be repeated here. the

Step 304: exit this process. the

There are many ways to exit the currently triggered conditional access service, such as displaying to the user through the terminal that there is no permission to use the current service. the

Figure 4 is a schematic diagram of an embodiment of the connection between the conditional interface unit and the memory card interface unit of the present invention. As shown in Figure 4, eight data lines (DB0-DB8) and four control signals are passed between the conditional interface unit and the memory card interface unit That is, request to send data signal (nInIntQ), ready to receive/send data signal (nInReady/nOutReady), request to receive data signal (nOutIntQ) and data latch clock signal (nLE). From the conditional receiving unit, the functions of each control signal are shown in Table 1:

control signal input Output Function Description Instructions Ready to receive signal (nInReady) output Input buffer status flag in the conditional receiving unit; form a pair of handshake signals with nInIntQ When nInReady=1, the input buffer is busy and does not receive data; when nInReady=0, the input buffer can receive data. Request to send data signal (nInIntQ) input Input a data request signal to the conditional receiving unit; form a pair of handshake signals with nInReady If set to active low Ready to send data signal (nOutReady) output Output buffer status flag in the conditional receiving unit; form a pair of handshake signals with nOutIntQ When nOutReady＝1, there is no data to output in the output buffer; when nOutReady＝0, there is data to output in the output buffer. Request to receive data signal (nOutIntQ) input Output data signal from conditional receiving unit; form a pair of handshake signals with nOutReady If set to active low

Data latch clock signal (nLE) input Input/Output Data Latch Clock When nInReady＝0, nInIntQ＝0 and nLE＝0, DB0～DB8 data are latched by the conditional receiving unit; nOutReady＝0, nOutIntQ＝0 and nLE＝0, DB0～DB8 output data. DB<7:0> two-way bidirectional data bus When nInReady＝0, nInIntQ＝0 and nLE＝0, DB0～DB8 are in input state; nOutReady＝0, nOutIntQ＝0 and nLE＝0, DB0～DB8 are in output state; others are in high impedance state

The process of data interaction between the conditional access unit and the storage control unit will be specifically described below. the

Fig. 5a is a sequence diagram of sending data from the memory card control unit to the conditional receiving unit of the present invention, and the sending process is roughly as follows:

After power-on self-test, the memory card control unit sends nInIntQ low pulse signal to the conditional receiving unit, requesting to send data; when the conditional receiving unit is ready, it returns nInReady low pulse signal to the memory card control unit, and the handshake is successful; the memory card control unit Generate the timing of sending data, that is, the nLE signal to the conditional receiving unit, and send data to the conditional receiving unit according to this timing. the

In the process of receiving data by the conditional receiving unit, as long as nInReady=0, data can be written without waiting; the pulse width of nLE is not less than 2ns, and the data on DB0~DB8 must be stable 1ns before the rising edge of nLE. After the rising edge of nLE, the data on DB0~DB8 is kept for at least 1ns. the

Figure 5b is a sequence diagram of the memory card control unit receiving data from the conditional access unit, and the receiving process is roughly as follows:

The memory card control unit sends the nOutIntQ low pulse, waiting to receive the data processed by the conditional receiving unit; after the conditional receiving unit is ready, it returns the nOutReady low pulse signal to the memory card control unit, and the handshake is successful; the memory card control unit generates the timing of receiving data That is, the nLE signal is given to the conditional receiving unit, and the data is received according to this timing. the

In the process of sending data by the conditional receiving unit, as long as nOutReady=0, the data can be read without waiting; the pulse width of nLE is not less than 2ns, and the data on DB0~DB8 can be stable and valid within 1ns after the falling edge of nLE. And within 1ns after the rising edge of nLE, DB0-DB8 are three-state. the

Fig. 5 a and Fig. 5 b are the embodiment of a kind of bus mode that memory card control unit and conditional receiving unit realize data transmission, also can adopt existing bus line, as I2C, SPI etc. carry out transmission, do not limit here. the

The above is only a preferred embodiment of the present invention, and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall include Within the protection scope of the present invention. the

Claims (4)

1. A memory card, comprising: a memory card control unit (100), a conditional access unit (101), a storage unit (102), and a memory card interface (103), wherein,

the memory card control unit (100) is used for controlling the memory card interface (103) to transmit and receive data, analyzing a protocol, managing the memory unit (102) and coordinating the units in the memory card;

a memory card interface (103) for receiving data from the outside and storing the data in the storage unit (102) under the control of the memory card control unit (100); the external data comprises a first information stream, a second information stream and scrambling information;

the conditional access unit (101) is used for acquiring a first information stream, a second information stream and scrambling information under the control of the memory card control unit (100), judging that the mobile terminal has service use authority for the scrambling information according to the second information stream, acquiring a corresponding service key according to the second information stream, decrypting a ciphertext control word in the first information stream by using the service key and acquiring a plaintext control word; and descrambling the scrambled information under the control of the plaintext control word to obtain the service data stream required by the mobile terminal user.

2. The memory card according to claim 1, wherein the conditional access unit (101) comprises: a right control module (1011), a service key extraction module (1012), a control word extraction module (1013), a descrambling module (1014), a file management module (1015) and a key management module (1016), wherein,

the authority control module (1011) sends an authentication success notification to the service key extraction module (1012) when the service identifier in the received second information flow is the same as the service identifier corresponding to the conditional access service supported by the user terminal and stored in the file management module (1015) in advance, and sends the second information flow to the service key extraction module (1012); when the received service identification is different from the stored service identification, exiting the current triggered conditional reception service;

a service key extraction module (1012) for receiving the authentication success notification, extracting the corresponding service key from the key management module (1016) according to the key seed ID number when the service key corresponding to the key seed ID number is stored in the key management module (1017) according to the key seed ID number, and sending the extracted service key to the control word extraction module (1013); when the ID number of the key seed in the second information flow is changed, the ID number of the corresponding service key in the memory card is updated;

the control word extraction module (1013) acquires a first information stream from the authority control module (1011), acquires a ciphertext control word from the first information stream, decrypts the ciphertext control word by using the service key from the service key extraction module (1012) to obtain a plaintext control word, and sends the plaintext control word to the descrambling module (1015);

and the descrambling module (1014) is used for acquiring the scrambled data from the storage unit (102) under the control of the memory card control unit (100), descrambling the scrambled data by using the plaintext control word from the control word extraction module (1013), and transmitting the descrambled data to the terminal through the memory card interface (105).

3. A memory card according to claim 1 or 2, characterized in that the protocol of the memory card interface (103) is a digital secure memory card or an MMC universal interface standard protocol.

4. The memory card according to claim 1 or 2, wherein the memory card control unit (100) and the conditional access unit (101) are connected by a data line to request transmission of a data signal, ready reception/transmission of a data signal, request reception of a data signal, and a data latch clock signal.

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