JP5516314B2 - IC card and IC card system capable of dynamically changing session buffer - Google Patents

Description

  The present invention relates to a technical field of an IC card which is a card mounted with an IC chip having a CPU and a memory. More specifically, the present invention is provided in an IC card according to the number of communication sessions established between terminal devices. The present invention relates to a technique for dynamically changing a session buffer.

  An IC chip mounted on an IC card is often provided with a UART (Universal Asynchronous Receiver Transmitter) corresponding to a communication protocol with an external terminal device, and data stored in a UART memory (for example, FIFO). APDU buffer (APDU: Application Protocol Data Unit) for data transfer is provided in the volatile memory (RAM) of the IC chip.

  In a SIM / USIM (Subscriber Identity Module / Universal Subscriber Identity Module) implemented in a mobile phone or an IC card used for financial purposes, a virtual communication session may be established between the terminal device and the IC card. The volatile memory of the IC chip mounted on such an IC card is provided with a session buffer for stacking data transmitted by the terminal device in addition to the APDU buffer.

  As a request for high functionality for recent IC cards, (Request 1) that the IC card can process a plurality of communication sessions in parallel, (Request 2) relatively large data (for example, 256-byte data) In order to satisfy such a requirement, it is necessary to manage the session buffer provided in the volatile memory of the IC card by some method.

  The following techniques are disclosed as techniques for managing the buffer size regardless of the IC card field. For example, Patent Document 1 discloses an invention that increases the buffer area by allocating another memory area to the buffer area when the size of the unused area in the buffer area to which the received data is written decreases to a predetermined size. ing.

  Further, in Patent Document 2, an area that can be used as a buffer is divided into a plurality of cells in segment units of the same size, and a buffer area is configured by some cells, and the size of an unused area in the buffer area An invention is disclosed in which an unused cell is added to a buffer area when the size is reduced to a predetermined size.

  The above-described prior art is an invention for increasing the size of the buffer area in accordance with the capacity of data transmitted from the terminal device. A personal computer that can secure a certain amount of volatile memory capacity is assumed as the target device. However, since the IC chip for the IC card is also required to be inexpensive, the capacity of the volatile memory of the IC chip is relatively small (for example, several kilobytes). It is not suitable for an IC card on which a small-sized IC chip is mounted.

  Further, since the above-described prior art executes a process of increasing the size of the buffer area after receiving data from the terminal device, an overhead associated with the processing is generated each time a command is transmitted from the terminal device, and the performance of the IC card is reduced. There is also the problem that it falls.

JP-A-8-221318 JP-A-10-91515

  Therefore, the present invention provides a session based on the number of open sessions so that a plurality of communication sessions can be processed in parallel and relatively large data can be processed within the constraints on the size of the volatile memory in the IC card. An object of the present invention is to provide an IC card that can optimize a buffer configuration and manage a session buffer provided in a volatile memory, and an IC card system using the IC card.

  A first invention for solving the above-mentioned problem is an IC card that holds a buffer area of a fixed size in a volatile memory and can establish a plurality of communication sessions in parallel, and each communication session has a session channel number. The session buffer associated with the session buffer is held in the fixed-size buffer, the number of session buffers, the address, and the channel number corresponding to each session buffer are held as session management information to establish a communication session. When receiving an instruction to close / close from the terminal device, the buffer area is divided according to a predetermined algorithm according to the number of communication sessions after establishment / closure, so that the size of the session buffer allocated to each communication session after establishment / closure And the address is calculated, and the session is calculated using the calculated value. And buffer management means for updating the management information, an IC card comprising the session management information output means for outputting the session management information to the external.

  Further, the second aspect of the present invention provides the session management information so that the size of the data stored in the session buffer is reflected in the session management information and the terminal device can acquire the size of the data stored in the session buffer. The total size of the data stacked in the session buffer is stored for each session buffer. When data is transmitted from the terminal device with the session channel number specified, the session management information is referred to and assigned to the channel number. The IC card according to the first aspect of the present invention, further comprising dispatch means for stacking the data in a designated session buffer and adding the size of the data to the total size of the session buffer.

  Furthermore, the third aspect of the present invention provides the buffer management means, wherein the data stored in the session buffer before the establishment / closure can be used even after the communication session is established / closed. According to the address of the session buffer assigned to each session after establishment / closure, the data stored in the session buffer before establishment / closure is relocated to the session buffer after establishment / closure before updating The IC card according to the second invention.

  Furthermore, the fourth aspect of the present invention provides data stored in the session buffer before establishment even if the size of the data stored in the session buffer before establishment exceeds the size of the session buffer after establishment. When the buffer management means receives an instruction to establish a communication session from the terminal device and rearranges the data, the buffer management means refers to the session management information, and determines the size of the data stacked in the session buffer, If there is a session buffer in which the size of the stacked data exceeds the size of the session buffer after establishment, processing that compares the size of the session buffer after establishment is performed. A third invention characterized in that data is saved in a rewritable nonvolatile memory An IC card according.

  Further, the fifth aspect of the present invention provides the buffer management so that the data stored in the session buffer before the establishment can be used even when the data is closed after being saved in a rewritable nonvolatile memory. If there is a session buffer in which data is saved in a rewritable non-volatile memory after receiving data from the terminal device and relocating the data after receiving an instruction to close the communication session, the non-volatile until the session buffer is completely filled. The IC card according to the fourth aspect of the present invention is characterized in that the data saved in the memory is returned to the session buffer.

  Furthermore, in the sixth invention, in order to prevent a communication session from being established beyond the maximum number of communication sessions that can be established on the IC card side, the maximum number of communication sessions that can be established is stored in the session management information. When receiving an instruction to establish a communication session from the terminal device, the buffer management means compares the number of established communication sessions with the maximum number of communication sessions, and the number of established communication sessions is the maximum number of communication sessions. In the IC card according to any one of the first and fifth inventions, the session management information is not updated.

  Further, a seventh invention is an IC card system using the IC card according to any one of the first invention to the sixth invention, and is any one of the first invention to the sixth invention. And a session management means for managing the number of communication sessions established between the IC cards by referring to the session management information acquired using the IC card described above and the session management information output means of the IC card An IC card system comprising a terminal device.

  Further, according to an eighth aspect of the invention, the session management means of the terminal device refers to the session management information acquired from the IC card, and sets the size of data to be transmitted to the IC card in a communication session between the IC cards. The IC card system according to the seventh aspect, wherein the management is performed for each established communication session.

  Thus, according to the present invention, an IC card capable of managing a session buffer provided in a volatile memory so that a plurality of communication sessions can be processed in parallel and relatively large data can be processed, and An IC card system using an IC card can be provided.

The figure explaining the IC card system concerning this embodiment. IC card software hierarchy diagram. The figure explaining session management information. The flowchart which showed the operation | movement when establishing a communication session newly. The flow figure of the data rearrangement process when establishing a communication session. The figure which showed an example which establishes a communication session newly. The flowchart which showed the operation | movement when closing a communication session. The flowchart of the data rearrangement process when closing a communication session. The figure which showed an example which closes a communication session. The flowchart of the process which a dispatch module performs. The figure explaining the function with which the terminal device was equipped.

  From here, embodiments of the present invention will be described to the extent that those skilled in the art in the technical field of the invention can understand the contents of the invention and implement the present invention.

  FIG. 1 is a diagram for explaining an IC card system 1 according to the present embodiment. The IC card system 1 according to the present embodiment includes at least an IC card 2 on which an IC chip 20 is mounted and a terminal device 3 that uses the IC card 2, and specific forms of the IC card 2 and the terminal device 3. Depends on the application of the IC card system 1.

  For example, when the IC card system 1 is a financial system, the IC card 2 is a cash card / credit card, and the terminal device 3 is an automatic teller machine or a credit terminal that cooperates with the IC card 2. When the IC card system 1 is a mobile phone / smart phone, the terminal device 3 is a mobile phone / smart phone, and the IC card 2 is a SIM / USIM (Subscriber Identity Module / Universal Subscriber Identity Module) mounted on the mobile phone / smart phone. )become.

  When the IC card 2 is used in a financial system or a mobile phone, when the application mounted on the IC card 2 is started, a communication session 30 for the started application is established, and the IC card 2 The session buffer 201 for stocking data transmitted from the terminal device 3 to the application by the communication session 30 established between the IC card 2 and the terminal device 3 is provided in the volatile memory (RAM 20c) of the IC card 2.

  As a request for higher functionality for the recent IC card 2, the IC card 2 can process a plurality of communication sessions 30 in parallel, and can process relatively large data (for example, 256-byte data) collectively. Every time a new communication session 30 is established between the IC card 2 and the terminal device 3, a session buffer 201 having a predetermined size (for example, 256 bytes) may be newly provided in the RAM 20c. As long as it is possible, the size of the RAM 20c of the IC chip 20 mounted on the IC card 2 is relatively small (for example, several Kbytes), and each time a communication session 30 is newly established in the IC card 2, a predetermined size is set. It is difficult to newly provide the session buffer 201 in the RAM 20c.

  Therefore, in the IC card 2 of the present embodiment, a fixed-size buffer area 200 used as the session buffer 201 is provided in the RAM 20c in advance, and when an instruction to establish / close the communication session 30 is received from the terminal device 3, By dividing the buffer area 200 into one or a plurality of session buffers 201 in software according to the number of communication sessions 30 and assigning one session buffer 201 to each communication session 30 after establishment / closure, To meet these two requirements.

  By dividing the buffer area 200 having a fixed size according to the number of communication sessions 30, the IC card 2 can process a plurality of communication sessions 30 in parallel, and the session buffer according to the number of communication sessions 30. Since the size of 201 is reduced / expanded, if the number of communication sessions 30 established between the IC cards 2 is managed according to the purpose on the terminal device 3 side, relatively large data (for example, 256 bytes of data) can be processed together.

  That is, if the number of communication sessions 30 established between the terminal device 3 and the IC card 2 is reduced, the size of the session buffer 201 is increased. If the number of communication sessions 30 is increased, the size of the session buffer 201 is reduced. When relatively large data (for example, 256-byte data) is to be processed collectively on the IC card 2 side, the number of communication sessions 30 may be managed in consideration of relatively large data.

  Furthermore, in this embodiment, when an instruction to establish / close the communication session 30 is received from the terminal device 3, the number of session buffers 201 provided in the RAM 20c of the IC card 2 is changed, thereby generating overhead related to the processing. Can be limited to when the communication session 30 is established / closed.

  In addition, in order to manage the number of communication sessions 30 on the terminal device 3 side, information related to the session buffer 201 in the IC card 2 is required. Therefore, the IC card 2 of the present embodiment includes the number of session buffers 201. Are stored in session management information corresponding to the channel number of the communication session 30 to which the session buffer 201 corresponds, and the terminal device 3 is provided with means for providing the session management information to the terminal device 3. The function of managing the number of communication sessions 30 and the size of data to be transmitted in the communication session 30 according to the session management information acquired from the communication session 30 is provided.

  First, the IC card 2 shown in FIG. 1 will be described. As shown in FIG. 1, the IC card 2 includes a ROM 20a that is a nonvolatile memory, an EEPROM 20b that is an electrically rewritable nonvolatile memory, a RAM 20c that is a volatile memory, a computer program mounted on the ROM 20a and the EEPROM 20b. The CPU 20e to be executed and the card on which the IC chip 20 having the UART 20d corresponding to the communication protocol with the terminal device 3 is mounted. One APDU buffer 202 for storing data received from the terminal device 3 and the buffer area 200 are configured in the RAM 20c. Has been.

  In FIG. 1, only the minimum elements of the IC chip 20 necessary for explaining the present invention are shown. In addition to those illustrated in FIG. 1, a timer, a cryptographic operation circuit used in the secure channel protocol, and the like are mounted on the IC chip 20.

  FIG. 2 is a hierarchy diagram of the software of the IC card 2. The software hierarchy of the IC card 2 is the hardware (IC chip 20), the operating system 21 (OS: Operating System), and the application 22 operating on the OS 21 in order from the lowest order. As one of the functions, a buffer that functions as a buffer management unit that dynamically changes the number and size of the session buffers 201 provided in the buffer area 200 according to the number of communication sessions 30 established between the terminal devices 3. When data is transmitted from the management module 210 and the terminal device 3 with the channel number of the communication session 30 specified, dispatch that refers to the session management information and stacks the data in the session buffer 201 assigned to the channel number Dispatch module that acts as a means 11, has a session management information output interface 212 which functions as the session management information output means for providing session management information indicating the configuration status of the session buffer 201 that is configured in the IC card 2 to the terminal device 3.

  First, the buffer management module 210 mounted on the IC card 2 will be described. When the buffer management module 210 receives an instruction to establish / close the communication session 30 from the terminal device 3, the buffer management module 210 dynamically changes the number and size of the session buffers 201 according to the number of the communication sessions 30 after establishment / closure, It is a computer program that performs processing for reflecting the changed contents in the session management information provided in the RAM 20c or the EEPROM 20b of the IC card 2.

  FIG. 3 is a diagram for explaining session management information in which information used for managing the session buffer 201 is stored. As shown in FIG. 3, in this embodiment, the session management information includes, as information related to the buffer area 200 provided in the RAM 20 c of the IC card 2, a buffer area start address that is the start address of the buffer area 200, and a buffer area The buffer area size indicating the size of 200 is included, and further, as information related to the session buffer 201, the maximum number of communication sessions 30 that can be established, that is, the maximum number indicating the maximum number of session buffers 201 that can be configured in the buffer area 200 The number of communication sessions, the number of established communication sessions 30, that is, the number of established communication sessions 30 indicating the number of session buffers 201 configured in the buffer area 200, and the session buffer that is the head address of each session buffer 201 lead Dress includes stack data size indicating the total size of the stack data in each session buffer 201.

  In the session management information shown in FIG. 3, the buffer area start address, the buffer area size, the maximum number of communication sessions and the number of established communication sessions are one, and the session buffer start address and stack data size are provided for the maximum number of communication sessions. The channel number (here, “00”, “01”, “02”, “03”) of the corresponding communication session 30 is assigned to the session buffer head address and the stack data size.

  The initial value of the session buffer head address is “0”. When the communication session 30 is established, the session buffer head address corresponding to the established communication session 30 is rewritten to the value obtained by calculation, and the communication session 30 When closed, the session buffer head address corresponding to the closed communication session 30 is rewritten to the initial value.

  In addition, the initial value of the stack data size is “0”, and the data is transmitted from the terminal device 3 by designating the channel number of the communication session 30, and every time data is stacked in the session buffer 201 corresponding to the channel number. When the communication session 30 is closed by adding the stack data size to the stack data size corresponding to the session buffer 201 in which the data is stacked, the stack data size corresponding to the closed communication session 30 is rewritten to the initial value.

  FIG. 4 is a flowchart showing an operation when a communication session 30 is newly established. When an instruction to establish the communication session 30 is received from the terminal device 3 by receiving a command for establishing the communication session 30 (for example, Global Platform SELECT Command or MANAGE CHANNEL Command) (S1), the buffer of the IC card 2 The management module 210 is activated, and an operation when a communication session 30 is newly established is started.

  When the operation for newly establishing the communication session 30 is started, the buffer management module 210 reads the contents of the session management information held at this time (for example, buffer area size, buffer area head address, established communication) Session etc.) is read (S2).

  Next, the buffer management module 210 divides the buffer area 200 according to a predetermined algorithm according to the number of established communication sessions 30 (S3), thereby calculating the size of the session buffer 201 allocated to each established session. (S4).

The present invention does not define an algorithm for dividing the buffer area 200 in accordance with the number of established communication sessions 30, and the algorithm may be arbitrary. However, in order to make the explanation of the present invention easier to understand, the algorithm Is an algorithm that equally divides the buffer area 200 in accordance with the number of established communication sessions 30, and the size of the established session buffer 201 is obtained by Equation 1.

When the buffer area 200 is divided according to the number of established communication sessions 30, the session buffer head address of the session buffer 201 assigned to each established session is calculated according to Equation 2 (S5), and the session buffer head address is young. Corresponding to sessions with a lower channel number in order.

  When calculating the session buffer head address of the session buffer 201 assigned to each established session, the buffer management module 210 confirms all the stack data size values stored in the session management information at this time (S6), The process branches depending on the result of checking the data size value (S7).

  When all the values of the stack data size are “0”, it means that no data is stacked in all the session buffers 201 configured in the buffer area 200 at this time. Processing for updating the session management information is performed without rearranging the data stacked in the session buffer 201 configured in 200 (S9), and this procedure is terminated.

  In the process of updating the session management information (S9), the buffer management module 210 increments the number of established communication sessions by one and then sets the session buffer head address corresponding to the communication session 30 for each established communication session 30. Is updated to the address calculated in S5 of FIG.

  Further, when all the values of the stack data size are not “0”, it means that data is stacked on all or part of the session buffer 201 corresponding to the communication session 30 established at this time. For each session buffer 201 whose stack data size value is not “0”, the session buffer 201 is set so that the start address of the data stacked in the session buffer 201 becomes the session buffer start address calculated in S5 of FIG. After executing a data rearrangement process for rearranging data stacked in the buffer 201 (S8), the session management information is updated (S9), and this procedure is terminated.

  FIG. 5 is a flowchart of the data rearrangement process when the communication session 30 is established. In the process of rearranging the data stacked in the session buffer 201, the buffer management module 210 first determines the size of the data to be rearranged, that is, the size of the data stacked in the target session buffer 201, 4 is compared with the size of the established session buffer 201 calculated in S4 (S10), and the process branches depending on the comparison result (S11).

  When the size of the data to be rearranged is equal to or smaller than the size of the session buffer 201 calculated in S4 of FIG. 4, the buffer management module 210 calculates the data stored in the target session buffer 201 in S5 of FIG. By executing the process of copying so that the first address becomes the first, the data stocked in the session buffer 201 area before establishment is rearranged in the session buffer 201 area after establishment (S12), End this procedure.

  If the size of the data to be rearranged exceeds the size of the session buffer 201 calculated in S4 of FIG. 4, the buffer management module 210 starts the session buffer calculated in S4 of FIG. By copying the data of size 201 so that the new head address calculated in s5 of FIG. 4 is at the head, a part of the data stocked in the session buffer 201 area before the establishment is copied After the data is rearranged in the session buffer 201 area (S13), the remaining data that does not fit in the size of the session buffer 201 calculated in S4 of FIG. 4 is copied into the designated area of the EEPROM 20b. The remaining data is saved in the EEPROM 20b (S14), and this procedure is completed. That.

  When data is copied in the designated area of the EEPROM 20b, the start address of the copy destination and the size of the copied data are stored in the session management information in association with the channel number of the target session buffer 201. .

  FIG. 6 is a diagram showing an example of establishing a new communication session 30, FIG. 6A is a diagram before establishing a new communication session 30, and FIG. 6B is a diagram showing the communication session 30. In the figure after newly established, in FIG. 6, the buffer area size is 3600 bytes, and the buffer area head address is 0xFF2000.

  According to FIG. 6A, the number of communication sessions 30 established before establishing a new communication session 30 is two channel numbers “00” and “01”. The size of the corresponding session buffer 201 is 1800 bytes obtained by dividing the buffer area size into two, the session buffer head address corresponding to the communication session 30 with the channel number “00” is 0xFF2000, and the communication with the channel number “01”. The session buffer head address corresponding to the session 30 is 0xFF2708.

  When a communication session 30 is newly established from the state of FIG. 6A, according to Equation 1, the size of the session buffer 201 after newly establishing the communication session 30 is divided into three equal sizes of the buffer area 200. 1200 bytes (3600 ÷ (2 + 1) = 1200).

  Further, according to Equation 2, each session buffer head address after newly establishing the communication session 30 is 0xFF2000, as shown in FIG. 6B, the session buffer head address of the channel number “00” is 0xFF2000. (0xFF2000 + (0 × 1200) = 0xFF2000), the session buffer head address of channel number “01” is 0xFF24B0 (0xFF2000 + (1 × 1200) = 0xFF24B0), and the session buffer head address of channel number “02” is 0xFF2960 (0xFF2000 + (2 × 1200) = 0xFF2960).

  In the above description, when the size of the data to be rearranged exceeds the size of the session buffer 201 calculated in S4 of FIG. 4, the data is saved in the EEPROM 20b. It is also possible to determine that the establishment of the communication session 30 has failed, invalidate the contents so far, maintain the state before newly establishing the communication session 30, and not update the session management information.

  Next, processing when the communication session 30 is closed will be described. FIG. 7 is a flowchart showing an operation when the communication session 30 is closed. When an instruction to close the communication session 30 is received from the terminal device 3 by receiving a command for closing the communication session 30 (for example, MANAGE CHANNEL Command of Global Platform) (S20), the buffer management module 210 of the IC card 2 is received. Is activated, and the operation of closing the communication session 30 is started.

  When the operation of closing the communication session 30 is started, the buffer management module 210 receives information stored in the session management information held by the buffer management module 210 at this time (for example, buffer area size, buffer area 200). Is read (S21).

Next, the buffer management module 210 divides the buffer area 200 according to a predetermined algorithm according to the number of communication sessions 30 after closing (S22), thereby calculating the size of the session buffer 201 allocated to each of the closed sessions. (S23).

When the size of the session buffer 201 assigned to each session after closing is calculated, the buffer management module 210 calculates the session buffer head address of the session buffer 201 assigned to each session after closing according to Equation 4 (S24). The communication sessions 30 with the youngest channel numbers are associated in ascending order of the head address.

  Next, the buffer management module 210 confirms all stack data size values except the stack data size corresponding to the communication session 30 to be closed (S25), and branches the process depending on the confirmation result of the stack data size value. (S26).

  When all of the confirmed stack data size values are “0”, this means that no data is stacked in all the session buffers 201 configured in the buffer area 200 at this time. The process of updating the session management information is performed without rearranging the data stacked in the session buffer 201 configured in the buffer area 200 (S28), and this procedure is terminated.

  In the process of updating the session management information (S28), the buffer management module 210 decrements the number of established communication sessions by one and then initializes the session buffer head address and stack data size corresponding to the closed communication session 30. At the same time, for each other communication session 30, the session buffer head address corresponding to the communication session 30 is updated to the address calculated in S24 of FIG.

  Further, when all the values of the confirmed stack data size are not “0”, it means that data is stacked in a part or all of the session buffer 201 corresponding to the communication session 30 that is not closed, and is closed. Except for the session buffer 201 corresponding to the communication session 30, for each session buffer 201 whose stack data size value is not “0”, the top of the data stacked in the session buffer 201 is the session calculated in S24 of FIG. After executing the data rearrangement process (S27) for rearranging the data stacked in the session buffer 201 so as to become the buffer head address, the session management information is updated (S28), and this procedure is terminated.

  FIG. 8 is a flowchart of data rearrangement processing when the communication session 30 is closed. In the process of rearranging the data stacked in the session buffer 201, first, the buffer management module 210 compares the size of the data to be rearranged with the size of the session buffer 201 calculated in S23 of FIG. 7 (S30), The process branches depending on the comparison result (S31).

  As described above, there is a case where a part of the data stacked in the session buffer 201 is saved in the EEPOM. In this case, the data saved in the EEPOM is used as the size of the data to be rearranged. Add the size of.

  When the size of the data to be rearranged is equal to or smaller than the size of the session buffer 201 calculated in S23 of FIG. 7, the buffer management module 210 calculates the data stored in the target session buffer 201 in S24 of FIG. By executing the copy process so that the session buffer head address becomes the head, the data stored in the session buffer 201 area before closing is rearranged in the session buffer 201 area after closing (S32). ), And finish this procedure.

  When the communication session 30 is closed, the size of the session buffer 201 increases. However, when a part of the data is saved in the EEPROM 20b, the size of the data to be rearranged is the session calculated in S23 of FIG. Since the size of the buffer 201 may be exceeded, in such a case, the buffer management module 210 starts with the top address calculated in S24 of FIG. 7 for all data stored in the session buffer 201 before closing. By copying in this way, after all the data stocked in the session buffer 201 area before closing is rearranged in the area of the session buffer 201 after closing (S33), until the session buffer 201 is completely filled, Data saved in the specified area of the EEPROM 20b The By executing the processing for copying, to return some or all of the data saved in EEPROM20b the volatile memory (S34), and ends this procedure.

  When a part of the data saved in the EEPROM 20b is restored to the RAM 20c, the size of the data remaining in the EEPROM 20b is stored in the session management information in association with the channel number of the target session buffer 201. deep.

  FIG. 9 is a diagram showing an example of closing the communication session 30, FIG. 9A is a diagram before closing the communication session 30, and FIG. 9B is a diagram after closing the communication session 30. In FIG. 9, the size of the buffer area 200 is 3600 bytes, and the top address is 0xFF2000.

  According to FIG. 9A, the number of communication sessions established before closing the communication session 30 is four channel numbers “00”, “01”, “02”, and “03”. The size of the session buffer 201 corresponding to each communication session 30 is 900 bytes obtained by equally dividing the buffer area size into four, the session buffer head address corresponding to the communication session 30 with the channel number “00” is 0xFF2000, and the channel number is The session buffer start address corresponding to the communication session 30 of “01” is 0xFF2384, the session buffer start address corresponding to the communication session 30 of channel number “02” is 0xFF2708, and the communication session 30 of channel number “03” is assigned. Corresponding session buffer top address is 0xFF It is A8C.

  When the communication session 30 with the channel number “02” is closed from the state of FIG. 9A, according to Equation 3, the size of the session buffer 201 after newly establishing the communication session 30 is the buffer area size. Is equal to 1200 bytes (3600 ÷ (4-1) = 1200).

  Also, according to Equation 4, each session buffer head address after closing the communication session 30 with the channel number “02” is the session number with the channel number “00” as shown in FIG. 9B. The buffer start address is 0xFF2000 (0xFF2000 + (0 × 1200) = 0xFF2000), the session buffer start address of channel number “01” is 0xFF24B0 (0xFF2000 + (1 × 1200) = 0xFF24B0), and the session buffer start of channel number “03” The address is 0xFF2960 (0xFF2000 + (2 × 1200) = 0xFF2960).

  From here, the dispatch module 211 provided in the IC card 2 will be described. FIG. 10 is a flowchart of processing executed by the dispatch module 211. When the terminal device 3 specifies the channel number of the communication session 30 and transmits data to the IC card 2, the UART 20D of the IC card 2 receives the data (S40), and the UART 20D receives the data according to the OS function of the IC card 2. The received data is stored in the APDU buffer 202 (S41).

  When the data received by the UART 20D is stored in the APDU buffer 202, the dispatch module 211 confirms predetermined data, for example, the CLA value of the command APDU, to thereby determine the channel number of the communication session 30 specified by the terminal device 3. (S42), referring to the session management information, stacking the data in the session buffer 201 assigned to the channel number (S43), and adding the size of the data to the total size of the session buffer 201 (S44), this procedure is terminated.

  In FIG. 1, four communication sessions 30 are established between the terminal device 3 and the IC card 2, and the two-digit number following “#” in FIG. 1 means the channel number of the communication session 30. For example, when the terminal device 3 specifies the channel number “01” of the communication session 30 and transmits data to the IC card 2, the data received by the UART 20 D of the IC card 2 from the terminal device 3 is temporarily stored in the APUD buffer 202. , The dispatch module 211 transfers the data in the APDU buffer 202 to the session buffer 201 corresponding to the channel number “01” designated by the terminal device 3, and the session corresponding to the channel number “01” received by the terminal device 3. Stack in the buffer 201.

  Next, a session management information output interface for providing session management information to the terminal device 3 will be described. This configuration information output interface can be realized by, for example, a unique command for notifying the terminal device 3 of session management information. In this case, when the command is received from the terminal device 3, the session management information at this time is transmitted to the terminal device. The process included in the response to be transmitted to the device 3 is executed.

  Finally, the content that the terminal device 3 manages the communication session 30 will be described. FIG. 11 is a diagram illustrating functions provided in the terminal device 3.

  As shown in FIG. 11, in order to manage a communication session 30 between the terminal device 3 and the IC card 2, the terminal device 3 includes a session management information acquisition unit 31 that acquires session management information from the IC card 2, Communication session management means 32 for managing the number of communication sessions 30 established between the terminal device 3 and the IC card 2 and the size of data transmitted in the communication session 30 based on the session management information acquired from the IC card 2 is provided. These means are realized by a computer program for operating the terminal device 3.

  The session management information acquisition means 31 of the terminal device 3 is means for acquiring session management information from the IC card 2 using the session management information output interface 212 of the IC card 2 every time the communication session 30 is established / closed. When the session management information output interface 212 is a command, it becomes a means for transmitting an APDU of the command to the IC card 2 and acquiring a response including the session management information from the IC card 2.

  The communication session management means 32 of the terminal device 3 manages the number of communication sessions 30 so as not to exceed the maximum number of communication sessions of the session management information acquired from the IC card 2, and collects relatively large data on the IC card 2 side. In the case of processing, management such as reducing the number of communication sessions 30 (for example, making it one) is performed. Further, the session buffer start address and the stack data size of the session management information acquired from the IC card 2 are referred to, and an operation for adjusting the size of data transmitted in the communication session 30 is performed so as not to exceed the size of the session buffer 201. .

1 IC card system 2 IC card 20 IC chip 20b EEPROM
20c RAM
20d UART
DESCRIPTION OF SYMBOLS 200 Buffer area 201 Session buffer 202 APDU buffer 210 Buffer management module 211 Dispatch module 212 Session management information output interface 3 Terminal device 30 Communication session 31 Session management information acquisition means 32 Communication session management means

Claims (8)

An IC card that holds a fixed-size buffer area in volatile memory and can open multiple communication sessions in parallel.
Each communication session holds a session buffer associated with the channel number of the session in the fixed size buffer, and the session buffer number, address, and channel number corresponding to each session buffer are held as session management information. And
When receiving an instruction to establish / close a communication session from a terminal device, the buffer area is divided according to a predetermined algorithm according to the number of established / closed communication sessions, and assigned to each established / closed communication session. Buffer management means for calculating the size and address of the session buffer and updating the session management information using the calculated value;
An IC card comprising session management information output means for outputting the session management information to the outside.   In the session management information, the total size of the data stacked in the session buffer is stored for each session buffer. When data is transmitted from the terminal device by specifying the session channel number, the session management information is referred to, 2. The IC card according to claim 1, further comprising dispatch means for stacking the data in a session buffer assigned to the channel number and adding the size of the data to the total size of the session buffer.   Before updating the session management information, the buffer management means, according to the address of the session buffer assigned to each session established / closed, updates the data stored in the session buffer before establishment / closing after establishment / closure. The IC card according to claim 2, wherein the IC card is rearranged in the session buffer.   The buffer management means refers to the session management information when receiving an instruction to establish a communication session from a terminal device and rearranges data, and determines the size of the data stacked in the session buffer and the session buffer after establishment. If there is a session buffer whose size exceeds the size of the session buffer after establishment, the size of the stacked data exceeds the size of the session buffer after establishment. 4. The IC card according to claim 3, wherein the IC card is saved in a volatile memory.   If there is a session buffer in which data is saved in a rewritable nonvolatile memory after receiving data from a terminal device and relocating data after receiving an instruction to close a communication session, the buffer management means is completely filled with the session buffer. The IC card according to claim 4, wherein the data saved in the nonvolatile memory is restored to the session buffer.   The maximum number of communication sessions that can be established is stored in the session management information. When the buffer management means receives an instruction to establish a communication session from a terminal device, the buffer management means determines the number of established communication sessions and the maximum number of communication sessions. 6. The IC card according to claim 1, wherein when the number of established communication sessions exceeds the maximum number of communication sessions, the session management information is not updated. .   The IC card according to any one of claims 1 to 6 and the session management information acquired by using the session management information output means of the IC card are referred to and established between the IC cards. An IC card system comprising a terminal device provided with session management means for managing the number of communication sessions. The session management means of the terminal device refers to session management information acquired from the IC card, and sets the size of data to be transmitted to the IC card in a communication session for each communication session established between the IC cards. The IC card system according to claim 7, wherein the IC card system is managed.

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