JP2007316865A - Memory card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To access a security protected region at a high speed, without deteriorating the strength of security. <P>SOLUTION: A session key encrypting/decrypting part 220 encrypts/decrypts data to be transmitted and received with host equipment 110 via a Host IF210 by using a session key Kss. A storage key encrypting/decrypting part 230 encrypts/decrypts data to be written in a flash memory 400 via an Flash IF240 or data to be read from the flash memory 400 by using a storage key Kst. An access management information encrypting part 330 encrypts the session key Kss and the storage key Kst, acquired from a key storage part 310 by an encryption key Ks generated by a key generation part 320, and transmits it to an SDC 200. An access management information decoding part 260 decrypts the received session key Kss and storage key Kst, by using the encryption Ks generated by a key generation part 250, and sets them in the session key encrypting/decrypting part 220 and the storage key encrypting/decrypting part 230. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a memory card that performs security processing.

  In a conventional memory card having a security function, for example, there is a technique described in Patent Document 1 as a technique for writing and reading data by accessing a Flash memory.

  Patent Document 1 discloses a memory card that includes a flash memory chip, a smart card chip, and a controller chip that controls reading and writing of data to and from the flash memory chip and the smart card chip in response to a request from the host device. Yes. This flash memory chip has a normal data area and a secure data area. The normal data area is an area for storing data from the host device. The secure data area is used by the smart card chip as an expansion memory and is a security protection area.

  Patent Document 2 discloses a storage device in which a smart card chip encrypts / decrypts data from a host device and stores it in a security protection area when the command from the host device includes information on security processing. Has been.

  In the memory card or the storage device described in Patent Document 1 and Patent Document 2, access to the security protection area is performed through steps as shown in FIG. 12, for example.

First, the host device 10 transmits a secure write command including a memory access to the security protection area 21 of the flash memory 20 to the controller chip 30 (step A). Next, the controller chip 30 converts this secure write command into an APDU (Application Protocol Data Unit) format and transfers it to the smart card chip 40 (step B). Next, after interpreting the APDU command, the application on the smart card chip 40 transmits a write / read transfer command, which is an access request to the security protection area 21 in the APDU format, to the controller chip 30 (step C). Next, the controller chip 30 accesses the security protection area 21 of the flash memory 20 according to the write / read transfer command, and performs a write / read process (step D). Next, the controller chip 30 returns a write / read response indicating the write / read processing result to the smart card chip 40 (step E). Next, the application on the smart card chip 40 assembles the write / read processing result indicated by the write / read response as a response APDU and sends it back to the controller chip 30 (step F). Then, the controller chip 30 returns a response APDU to the host device 10 when receiving the secure read command (step G).
JP 2004-295160 A JP 2003-22216 A

  However, in the conventional memory card or storage device, it is necessary to exchange data between the controller chip and the smart card chip in order to ensure the strength of security. As a result of the excessive exchange of data, access to the flash memory is required. There is a problem that the speed becomes low.

  In particular, when accessing the security protection area, there is a problem that the number of communication between the controller chip and the smart card chip and the amount of data transmitted and received are large, and a sufficient access speed cannot be obtained. When data stored in the security protection area is encrypted / decrypted, the encryption / decryption is performed by the smart card chip, so that the encrypted / decrypted data is exchanged between the controller chip and the smart card chip. In this respect, the access speed to the security protection area has a certain limit.

  The present invention has been made in view of this point, and an object of the present invention is to provide a memory card that can access a security protection area at high speed without reducing security strength.

  The memory card of the present invention includes a smart card chip that executes data writing to the memory chip or data reading from the memory chip, and a controller chip that controls data writing or reading executed by the smart card chip. In the provided memory card, data transmitted between the memory chip and the smart card chip, and a first encryption / decryption unit that performs encryption / decryption processing on data transmitted between the memory card and an external device And a second encryption / decryption unit that performs encryption / decryption processing, and at least one of the first encryption / decryption unit and the second encryption / decryption unit is provided in the controller chip.

  The method of accessing the memory chip of the memory card according to the present invention includes a data transmission step of executing data writing to the memory chip or data reading from the memory chip with the smart card chip, and the data transmission step with the controller chip. And a step of accessing the memory chip of the memory card, wherein the data is transmitted / received between the memory card and an external device. A first encryption / decryption step; and a second encryption / decryption step for performing encryption / decryption processing on data transmitted between the memory chip and the smart card chip. At least one of the two encryption / decryption steps is executed by the controller chip. Was to so that.

  According to the present invention, it is possible to reduce the number of times of communication between the controller chip and the smart card chip and the amount of data transmitted and received in the security processing. As a result, access to the security protection area can be speeded up.

  In addition, it is possible to prevent unauthorized interception of the session key Kss and the storage key Kst used for security processing due to spoofing or wiretapping of the controller chip, and thus it is possible to access the security protection area without reducing the security strength.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
In the present embodiment, as shown in FIG. 1, data is exchanged between the SDC (SD controller chip) 200 and the SCC (smart card chip) 300 to the flash memory (Flash) 400 from the host device 110. The memory card 100 for writing predetermined data will be described.

  Specifically, in the present embodiment, the SDC 200 performs encryption / decryption processing of data transmitted between the host device 110 and the session key encryption / decryption unit 220 provided in the SDC 200 and the flash memory 400. And a storage key encryption / decryption unit 230 provided in the SDC 200 for performing encryption / decryption processing of data transmitted by the SDC 200.

  The key storage unit 310 provided in the SCC 300 holds a session key Kss that the session key encryption / decryption unit 220 uses for encryption / decryption processing, and a storage key Kst that the storage key encryption / decryption unit 230 uses for encryption / decryption processing. It is configured as follows.

  In addition, the key generation unit 250 provided in the SDC 200 and the key generation unit 320 provided in the SCC 300 authenticate each other and then perform encryption / decryption processing on data transmitted through the communication channel between the SDC 200 and the SCC 300 It is configured to generate an encryption key Ks for this purpose. Here, the data transmitted through the communication path between the SDC 200 and the SCC 300 includes, for example, a session key Kss and a storage key Kst held by the key storage unit 310.

  The memory card 100 will be described in detail below.

  FIG. 1 is a block diagram showing a configuration of a memory card 100 according to Embodiment 1 of the present invention.

  1, the memory card 100 includes an SD (Secure Digital) controller chip (hereinafter abbreviated as “SDC”) 200, a smart card chip (hereinafter abbreviated as “SCC”) 300, and a flash memory 400.

  The memory card 100 can be inserted into a terminal of a host device 110 such as a mobile phone, a PDA (Personal Digital Assistant), or a PC (Personal Computer). The memory card 100 also has a function of transmitting / receiving various data to / from the connected host device 110.

  The SDC 200 is connected to the SCC 300 and the flash memory 400, and controls the writing of data into the flash memory 400 and the reading of data from the flash memory 400, particularly the writing and reading of data requiring security processing.

  The SDC 200 includes a host interface (hereinafter referred to as “Host IF”) 210, a session key encryption / decryption unit 220, a storage key encryption / decryption unit 230, a flash interface (hereinafter referred to as “Flash IF”) 240, a key generation unit 250, and an access management information decryption. Section 260 and an SCC interface (hereinafter referred to as “SCC IF”) 270.

  The Host IF 210 transmits / receives various data to / from the host device 110. When Host IF 210 receives a command to access flash memory 400 from host device 110, Host IF 210 outputs the command to SCC IF 270. The command for accessing the flash memory 400 includes, for example, an access area designation command indicating which area in the flash memory 400 is accessed, and a data transfer command including data to be written in the accessed area or an area to be accessed. A data acquisition command including power data is included. The access area designation command includes information such as an area number, a block address, and a block length for specifying an area to be accessed.

  When the command from the host device 110 indicates writing data to the flash memory 400 (data transfer command), the Host IF 210 outputs the data to be written to the flash memory 400 and the data transfer command to the session key encryption / decryption unit 220. Further, when the command from the host device 110 indicates reading of data from the flash memory 400 (data acquisition command), the Host IF 210 outputs the data acquisition command to the Flash IF 240, and the data read from the flash memory 400 is output. Transmit to the host device 110.

  In addition, when receiving a reset request command from the host device 110, the Host IF 210 outputs the reset request command to the key generation unit 250 and the SCC IF 270.

  Here, the “reset request command” is a command including a request for generating a key for encrypting / decrypting data transmitted through the communication path between the SDC 200 and the SCC 300. The reset request command will be described in detail later in the operation description.

  The session key encryption / decryption unit 220 serving as the first encryption / decryption unit encrypts / decrypts data transmitted / received to / from the host device 110 via the Host IF 210 using the session key Kss. The session key Kss is stored in the access management information held by the key storage unit 310 of the SCC 300 in association with the area designated by the access area designation command. Therefore, the session key Kss may differ depending on the area specified by the access area specifying command of the flash memory 400. The session key Kss stored in the access management information will be described in detail later.

  When writing data, the session key encryption / decryption unit 220 decrypts data to be written to the flash memory 400 transmitted from the host device 110 via the Host IF 210 with the session key Kss. Further, the session key encryption / decryption unit 220 outputs the data decrypted with the session key Kss to the storage key encryption / decryption unit 230.

  The session key encryption / decryption unit 220 encrypts the data read from the flash memory 400 with the session key Kss when reading the data. In addition, the session key encryption / decryption unit 220 transmits data encrypted with the session key Kss to the host device 110 via the Host IF 210.

  The storage key encryption / decryption unit 230 as the second encryption / decryption unit encrypts / decrypts data to be written to the flash memory 400 or data to be read from the flash memory 400 via the Flash IF 240 using the storage key Kst. This storage key Kst is stored in the access management information held by the key storage unit 310 of the SCC 300 in association with the area designated by the access area designation command. Therefore, the storage key Kst may differ depending on the area specified by the access area specifying command of the flash memory 400. The storage key Kst stored in the access management information will be described in detail later.

  When writing data, the storage key encryption / decryption unit 230 encrypts the write data to the flash memory 400 input from the session key encryption / decryption unit 220 with the storage key Kst. The storage key encryption / decryption unit 230 transmits the write data encrypted by the storage key Kst to the area specified by the access area specification command of the flash memory 400 via the Flash IF 240.

  When reading data, the storage key encryption / decryption unit 230 uses the storage key Kst to decrypt data read from the area specified by the access area specification command of the flash memory 400 and input via the Flash IF 240. The storage key encryption / decryption unit 230 outputs the read data decrypted with the storage key Kst to the session key encryption / decryption unit 220.

  The Flash IF 240 transmits / receives various data to / from the flash memory 400. Specifically, the Flash IF 240 transmits data to be written to the flash memory 400 input from the storage key encryption / decryption unit 230 to an area designated by the access area designation command of the flash memory 400. Further, the Flash IF 240 receives data read from the area specified by the access area specifying command of the flash memory 400 and outputs the received data to the storage key encryption / decryption unit 230.

  The key generation unit 250 as a decryption security key generation unit generates an encryption key Ks for encrypting / decrypting data transmitted / received between the SDC 200 and the SCC 300. Specifically, the key generation unit 250 uses the encryption key Kps stored in a memory (not shown) in the key generation unit 250 as ATR (Answer to Reset) data transmitted from the SCC 300 during the reset process. An encryption key Ks is generated by encrypting the set random number Rn. The key generation unit 250 sets the generated encryption key Ks in the access management information decryption unit 260.

  When generating the encryption key Ks, the key generation unit 250 uses the authentication key Km stored in a memory (not shown) in the key generation unit 250 to set the ATR data transmitted from the SCC 300 during the reset process. An authenticator (MAC1) is generated from the random number Rn. In addition, the key generation unit 250 transmits the generated authenticator (MAC1) and a verification command for the authenticator (MAC1) to the SCC 300 via the SCC IF 270. The encryption key Kps and the authentication key Km may be stored as program codes in a ROM (Read Only Memory) (not shown) in the SDC 200.

  The access management information decryption unit 260 as a security key decryption unit decrypts various information transmitted and received between the SDC 200 and the SCC 300 using the encryption key Ks generated by the key generation unit 250.

  The access management information decryption unit 260 decrypts the encrypted access management information corresponding to the area designated by the access area designation command transmitted from the SCC 300 via the SCC IF 270 using the encryption key Ks. The encrypted access management information includes, for example, an area number, a physical address, an access length, information for specifying an area to be accessed in the flash memory 400 such as an ID of an application that owns the area, a session key Kss and its encryption algorithm. Information indicating the storage key Kst and its encryption algorithm.

  The access management information decryption unit 260 sets the decrypted session key Kss in the session key encryption / decryption unit 220. Further, the access management information decryption unit 260 sets the decrypted storage key Kst in the storage key encryption / decryption unit 230. Further, the access management information decoding unit 260 sets information for specifying an area to be accessed in the flash memory 400 in the Flash IF 240.

  The SCC IF 270 transmits / receives various data to / from the SCC 300. Specifically, the SCC IF 270 transmits various commands such as an access area designation command and a reset request command input from the host device 110 via the Host IF 210 to the SCC 300. Further, the SCC IF 270 receives ATR data, encrypted access management information, and the like transmitted from the SDC IF 340 of the SCC 300. Further, the SCC IF 270 outputs the received ATR data to the key generation unit 250, and outputs the received encrypted access management information to the access management information decryption unit 260.

  As the SCC IF 270, an interface conforming to the ISO / IEC 7816 standard can be used.

  The SCC 300 is a microcomputer chip used in IC cards and smart cards, such as a CPU (Central Processing Unit) and EEPROM (Electrically Erasable Programmable Read Only Memory) and FeRAM (Ferroelectric Random Access Memory) for executing smart card applications. It has a non-volatile memory. Further, the SCC 300 has an encryption function necessary for security processing.

  The SCC 300 includes a key storage unit 310, a key generation unit 320, an access management information encryption unit 330, and an SDC IF 340.

  The key storage unit 310 holds access management information. The access management information includes information for specifying an area to be accessed in the flash memory 400, session encryption information including a session key Kss and its encryption algorithm, and storage encryption information including a storage key Kst and its encryption algorithm. Are stored in association with each other.

  Here, the access management information held by the key storage unit 310 will be specifically described with reference to FIG. FIG. 2 is a diagram illustrating an example of access management information.

  In FIG. 2, access management information 500 indicates an area number 510 indicating the area number of the area to be accessed, a physical address 520 indicating the physical address of the area to be accessed, and the ID of the application that owns the area to be accessed. It includes an application ID 530, session encryption information 540 indicating session encryption information used for an area to be accessed, and storage encryption information 550 indicating storage encryption information used for an area to be accessed. The session encryption information 540 includes a session key 541 used for session encryption and its encryption algorithm 542, and the storage encryption information 550 includes a storage key 551 used for storage encryption and its encryption algorithm 552.

  For example, “area 1” exists at the physical address “0x00000000” and is owned by the application ID “AP1”. The session key used when accessing “area 1” is “Kss1”, and the encryption algorithm is “T-DES CBC”. Further, the storage key used when storing data in “area 1” is “Kst1”, and the encryption algorithm is “AES”.

  “Area 2” exists at the physical address “0x00002000” and is owned by the application ID “AP1”. The session key used when accessing “area 2” is “Kss2”, and the encryption algorithm is “T-DES CBC”. Also, the storage key used when storing data in “area 2” is “Kst1”, and the encryption algorithm is “AES”.

  “Area 3” exists at the physical address “0x00004000” and is owned by the application ID “AP2”. Further, when accessing “area 3”, the session key is not used. The storage key used when storing data in “area 3” is “Kst2”, and the encryption algorithm is “AES”.

  Thus, in the access management information 500, session encryption information and stored encryption information are stored in association with each area number of the flash memory 400.

  When receiving the reset request command transmitted from the SDC 200 via the SDC IF 340, the key generation unit 320 as the encryption security key generation unit generates a random number Rn and generates ATR data in which the random number Rn is set. Further, the key generation unit 320 transmits the generated ATR data to the SDC 200 via the SDC IF 340. Here, the key generation unit 320 can set the generated random number Rn to, for example, “Historical Character” of 15 bytes of ATR data.

  The key generation unit 320 generates and transmits the ATR data, and uses the authentication key Km stored in a memory (not shown) in the key generation unit 320 to generate a random number Rn generated when the reset request command is received. Generates an authenticator (MAC2).

  The key generation unit 320 compares the authenticator (MAC1) and the authenticator (MAC2) generated by the key generation unit 250 of the SDC 200. If these authenticators are correct, the key generator 320 determines whether the authenticator is correct between the SCC 300 and the SDC 200. An encryption key Ks for encrypting / decrypting transmitted / received data is generated. Specifically, the key generation unit 320 uses the encryption key Kps stored in the memory (not shown) in the key generation unit 320 to encrypt the random number Rn generated when the reset request command is received. Thus, the encryption key Ks is generated. Further, the key generation unit 320 sets the generated encryption key Ks in the access management information encryption unit 330. The encryption key Kps and the authentication key Km are set in the key storage unit 310 when the SCC 300 is manufactured, for example.

  Here, the encryption key Kps and the authentication key Km stored in the memory in the key generation unit 250 of the SDC 200 are the same as the encryption key Kps and the authentication key Km stored in the memory in the key generation unit 320 of the SCC 300. is there. Therefore, when the authenticator (MAC1) and the authenticator (MAC2) are correct authenticators, the encryption key Ks generated by the key generation unit 250 of the SDC 200 and the encryption key Ks generated by the key generation unit 320 of the SCC 300 Are the same. Thereby, the encryption key Ks can be shared between the SDC 200 and the SCC 300, and the safety and reliability of data transmission / reception between the SDC 200 and the SCC 300 can be improved.

  When the access management information encryption unit 330 as the security key encryption unit receives the access area designation command transmitted from the SDC 200, the access management information encryption unit 330 obtains the access management information corresponding to the access area designation command from the access management information held by the key storage unit 310. get. Specifically, first, the access management information encryption unit 330 specifies the area number of the area to be accessed or the physical address of the area to be accessed based on the access area designation command. Then, the access management information encryption unit 330 acquires the specified area number or physical address, and session encryption information and stored encryption information corresponding to these as access management information.

  The access management information encryption unit 330 encrypts the acquired access management information using the encryption key Ks generated by the key generation unit 320. Further, the access management information encryption unit 330 transmits the encrypted access management information to the SDC 200 via the SDC IF 340.

  The SDC IF 340 transmits / receives various data to / from the SDC 200. Specifically, the SDC IF 340 transmits the ATR data generated by the key generation unit 320, the access management information encrypted by the access management information encryption unit 330, and the like to the SDC 200. The SDC IF 340 receives various commands such as an access area designation command and a reset request command transmitted from the SCC IF 270 of the SCC 200. The SDC IF 340 outputs the received access area designation command to the access management information encryption unit 330 and outputs the received reset request command to the key generation unit 320.

  As the SDC IF 340, an interface conforming to the ISO / IEC7816 standard can be used. Thereby, a standard smart card chip can be applied as the SCC 300 of the present invention.

  The flash memory 400 is a memory chip that uses a nonvolatile semiconductor memory as a storage medium. The flash memory 400 can write and read data by flash memory commands such as a data transfer command and a data acquisition command.

  The flash memory 400 has a normal area 410 and a security protection area 420. The security protection area 420 is divided by a plurality of area blocks 421, 422, 423, and 424.

  The normal area 410 is an area for writing and reading standard data that does not require security processing. When the normal area 410 is designated by the access area designation command from the host device 110, the data from the host device 110 is written into the normal area 410, or the data stored in the normal area 410 is read out and the host device 110 is read out. Sent to. Note that when data is written to the normal area 410 and data is read from the normal area 410, whether or not to perform encryption / decryption with the session key Kss and the storage key Kst is arbitrary.

  The security protection area 420 is an extended memory area for writing and reading highly confidential information such as personal information and confidential information. Each area block constituting the security protection area 420 is a minimum area unit that can be designated by an access area designation command. Each area block constituting the security protection area 420 can be assigned for each application of the SCC 300, for example. Here, the security protection area 420 is divided into four area blocks 421, 422, 423, and 424. However, the number of area blocks constituting the security protection area 420 is not particularly limited, and can be arbitrarily set. it can.

  Data written to the security protection area 420 and data read from the security protection area 420 are transmitted and received between the memory card 100 and the host device 110 in a state encrypted with the session key Kss associated with each area block. Is done. The data stored in the security protection area 420 is stored in each area block in an encrypted state with the storage key Kst associated with each area block. Note that when a mode in which data encryption with the session key Kss is not performed is set according to an agreement between the application and the host device 110, encryption with the session key Kss is not performed.

  The configuration of the SDC 200, the SCC 300, and the flash memory 400 of the memory card 100 has been described above.

  Next, the operation of the memory card 100 configured as described above will be described in detail with reference to FIGS.

  First, the mechanism of authentication and sharing of the encryption key Ks between the SDC 200 and the SCC 300 in the reset process will be described with reference to FIG.

  FIG. 3 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when the encryption key Ks is generated by the reset process. Here, a case where reset processing is performed by a reset request command transmitted from the host device 110 will be described.

  First, the host device 110 generates a reset request command and transmits the generated reset request command to the SDC 200 of the memory card 100 (S1). The reset request command received by the Host IF 210 of the SDC 200 is output to the key generation unit 250 and the SCC IF 270. Further, the SCC IF 270 further transmits the input reset request command to the SCC 300 (S2). The reset request command received by the SDC IF 340 of the SCC 300 is output to the key generation unit 320.

  When the key generation unit 320 receives the reset request command and determines to perform the reset process, the key generation unit 320 generates a random number Rn (S3). Further, the key generation unit 320 generates ATR data in which the random number Rn generated in step S3 is set according to the ISO / IEC 7816 standard, and transmits the generated ATR data to the SDC 200 via the SDC IF 340 (S4). At this time, the key generation unit 320 sets the random number Rn to, for example, “Historical Character” of 15 bytes of ATR data. Further, the ATR data received by the SCC IF 270 of the SDC 200 is output to the key generation unit 250.

  The key generation unit 250 generates an authenticator (MAC1) from the random number Rn set in the ATR using the authentication key Km stored in a memory (not shown) inside the key generation unit 250 (S5). Further, the key generation unit 250 generates a verification command including the generated authenticator (MAC1), and transmits this verification command to the SCC 300 (S6).

  In addition, the key generation unit 250 performs the processes of steps S5 and S6, and uses the encryption key Kps stored in the memory (not shown) inside the key generation unit 250 to set the random number Rn set in the ATR data. Is encrypted to generate an encryption key Ks (S7).

  When the key generation unit 320 of the SCC 300 receives the verification command including the authenticator (MAC1) from the SDC 200, the key generation unit 320 uses the authentication key Km stored in the memory (not shown) inside the key generation unit 320 in step S3. An authenticator (MAC2) is generated from the generated random number Rn (S8). Further, the key generation unit 320 compares the authenticators (MAC1) and the authenticators (MAC2), and confirms the validity of these authenticators (S9). If the authenticator (MAC1) and authenticator (MAC2) are correct, the key generation unit 320 generates the key generation unit 320 in step S3 using the encryption key Kps stored in the memory (not shown) inside the key generation unit 320. The encryption key Ks is generated by encrypting the random number Rn (S10).

  Here, since the key generation unit 320 generates the random number Rn every time the reset process is performed, the encryption key Ks generated using the random number Rn may be different every time the reset process is performed. Therefore, the SDC 200 and the SCC 300 generate a different encryption key Ks each time reset processing is performed, and the generated encryption key Ks is used to encrypt / decrypt information related to security processing, for example, access management information for each area block in the security protection area 420. Will be sent and received. As a result, it is possible to prevent unauthorized interception of information related to security processing transmitted / received between the SDC 200 and the SCC 300 due to spoofing or wiretapping of the SDC 200. That is, the risk of unauthorized access to the security protection area 420 can be reduced.

  In the example of FIG. 3, the case where the reset process is performed by the reset request command transmitted from the host device 110 has been described, but the present invention is not limited to this. For example, the reset processing may be automatically performed, for example, at a timing when the memory card 100 detects power-on or when the memory card 100 detects connection of the host device 110. Further, the reset process may be performed every predetermined time set in advance.

  In the example of FIG. 3, the mechanism of sharing the encryption key Ks in the reset process has been described, but the present invention is not limited to this. For example, a command for sharing the encryption key Ks between the SDC 200 and the SCC 300 is defined, and the SCC 300 that has received this command returns a random number Rn as a response, and the above-described authentication process and encryption key Ks generation process May be performed.

  The mechanism of authentication and sharing of the encryption key Ks between the SDC 200 and the SCC 300 in the reset process has been described above.

  Next, a data write operation to the security protection area 420 of the flash memory 400 will be described with reference to FIG.

  FIG. 4 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when data is written to the security protection area 420 of the memory card 100. Here, a case where data is written to the area block 421 of the security protection area 420 will be described. For simplicity, it is assumed that the area block 421 corresponds to “area 1” of the access management information shown in FIG.

  In FIG. 4, data is written to the security protection area 420 in order to set various information corresponding to the area in which data is written, access area designation command processing (steps S11 to S16), and to actually write data. The data transfer command process (steps S17 to S21) is performed in two steps.

[Access area specification command processing]
First, access area designation command processing will be described.

  First, the host device 110 transmits an access area designation command in which an area number, a block address, and a block length for specifying an area to be accessed are described to the SDC 200 (S11). The access area designation command received by the Host IF 210 of the SDC 200 is output to the SCC IF 270. Further, the SCC IF 270 further transmits the input access area designation command to the SCC 300 (S12). The access area designation command received by the SDC IF 340 of the SCC 300 is output to the access management information encryption unit 330.

  When the access management information encryption unit 330 receives the access area designation command, the access management information corresponding to the access area designation command, for example, the physical address of the area to be accessed, the access length, from the access management information held by the key storage unit 310 The session key Kss and the storage key Kst are acquired (S13). In this example, the access management information encryption unit 330 acquires the physical address 0x00000000, access length, session key Kss1, and storage key Kst1 corresponding to the area block 421 (area 1) as access management information.

  The access management information encryption unit 330 uses the encryption key Ks generated by the key generation unit 320 to obtain the access management information acquired in step S13, that is, the physical address corresponding to the area block 421, the access length, the session key Kss, and The storage key Kst is encrypted. The access management information encryption unit 330 transmits the encrypted access management information to the SDC 200 (S14). The encrypted access management information received by the SCC IF 270 of the SDC 200 is output to the access management information decryption unit 260.

  The access management information decryption unit 260 of the SDC 200 decrypts the encrypted access management information from the SCC 300 using the encryption key Ks generated by the key generation unit 250. As a result, the access management information decryption unit 260 acquires the physical address 0x00000000, access length, session key Kss1, and storage key Kst1 corresponding to the access destination, that is, the area block 421 (S15).

  Then, the access management information decryption unit 260 sets the session key Kss1 acquired in step S15 in the session key encryption / decryption unit 220, and sets the storage key Kst1 acquired in step S15 in the storage key encryption / decryption unit 230. Further, the access management information decoding unit 260 sets the physical address and access length acquired in step S15 in the Flash IF 240 (S16).

[Data transfer command processing]
Next, data transfer command processing will be described.

  First, the host device 110 encrypts data to be written in the area block 421 using the session key Kss, for example, the session key Kss1 (S17). Here, the host device 110 shares the session key Kss with the memory card 100 in advance. Further, for example, it is possible to share a session key by using a key exchange process such as Diffe-Helman.

  In addition, the host device 110 transmits to the SDC 200 a data transfer command instructing data writing together with the write data encrypted by the session key Kss1 (S18). The write data received by the Host IF 210 of the SDC 200 is output to the session key encryption / decryption unit 220.

  The session key encryption / decryption unit 220 decrypts the encrypted write data from the host device 110 using the session key Kss1 set in step S16 (S19). Next, the storage key encryption / decryption unit 230 encrypts the decrypted write data using the storage key Kst1 set in step S16 (S20). Then, the write data encrypted with the storage key Kst1 is written to the area indicated by the physical address set in the Flash IF 240 in step S16, for example, the area block 421 via the Flash IF 240.

  The data write operation to the security protection area 420 of the flash memory 400 has been described above.

  Next, a data read operation from the security protection area 420 of the flash memory 400 will be described with reference to FIG.

  FIG. 5 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when data is read from the security protection area 420 of the memory card 100. Here, a case where data stored in the area block 421 of the security protection area 420 is read will be described. For simplicity, it is assumed that the area block 421 corresponds to “area 1” of the access management information shown in FIG.

  In FIG. 5, data is read from the security protection area 420 in order to set various information corresponding to the data reading area (steps S11 to S16) and to actually read the data. The data acquisition command process (steps S31 to S36) is performed in two steps. The access area designation command process in FIG. 5 is the same as the access area designation command process in FIG. 4 described above, so that the description thereof will be omitted and only the data acquisition command process will be explained.

[Data acquisition command processing]
First, the host device 110 transmits a data acquisition command for instructing data reading to the SDC 200 (S31). The data acquisition command received by the Host IF 210 of the SDC 200 is output to the Flash IF 240.

  The Flash IF 240 reads the data stored in the area indicated by the physical address set in step S16, for example, the area block 421 (S32). This read data is output to the storage key encryption / decryption unit 230.

  The storage key encryption / decryption unit 230 decrypts the data read from the area block 421 using the storage key Kst1 set in step S16 (S33). Next, the session key encryption / decryption unit 220 encrypts the decrypted read data using the session key Kss1 set in step S16 (S34). Then, the read data encrypted with the session key Kss1 is transmitted to the host device 110 via the Host IF 210 (S35).

  The host device 110 acquires plaintext read data by decrypting the encrypted read data from the SDC 200 using the session key Kss1 (S36).

  The operation for reading data from the security protection area 420 of the flash memory 400 has been described above.

  As described above, according to the present embodiment, the encryption / decryption of the access data to the security protection area 420 by the session key Kss and the encryption / decryption by the storage key Kst are performed by the SDC 200, so the SDC 200 and the SCC 300 in the security process It is possible to reduce the number of communications between them and the amount of data transmitted and received. Thereby, the access to the security protection area 420 can be speeded up.

  In addition, the session key Kss and the storage key Kst are stored in the SCC 300, and the encryption key Ks shared between the SDC 200 and the SCC 300 when a command for performing security processing, for example, an access area designation command is received. Since it is encrypted and transmitted to the SDC 200, unauthorized interception of the session key Kss and the storage key Kst due to spoofing or wiretapping of the SDC 200 can be prevented. Thereby, the risk of unauthorized access to the security protection area 420 can be reduced.

  Furthermore, since the SDC 200 and the SCC 300 appropriately perform reset processing to mutually authenticate each other and regenerate the shared encryption key Ks, the safety and reliability of the encryption key Ks can be improved.

(Embodiment 2)
In the present embodiment, the session key encryption / decryption unit 610 provided in the SDC 200 performs encryption / decryption processing of data transmitted to / from the external device 110, and encryption / decryption of data transmitted to / from the flash memory 400 is performed. The memory card 600 configured so that the storage key encryption / decryption unit 660 provided in the SCC 300 performs the process will be described.

  FIG. 6 is a block diagram showing the configuration of the memory card 600 according to Embodiment 2 of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and description of overlapping portions is omitted. Further, only the additional functions of the components having additional functions in the components of FIG. 1 will be described.

  6, the SDC 200 of the memory card 600 includes a session key encryption / decryption unit 610, an access management information encryption / decryption unit 620, a Flash IF 630, and an SCC IF 640.

  The session key encryption / decryption unit 610 encrypts / decrypts data transmitted / received to / from the host device 110 via the Host IF 210 using the session key Kss.

  When writing data, the session key encryption / decryption unit 610 decrypts the write data to the flash memory 400 transmitted from the host device 110 with the session key Kss. In addition, session key encryption / decryption unit 610 outputs the decrypted write data to access management information encryption / decryption unit 620.

  When reading data, the session key encryption / decryption unit 610 encrypts the read data from the flash memory 400 input from the access management information encryption / decryption unit 620 with the session key Kss. In addition, the session key encryption / decryption unit 610 transmits the encrypted read data to the host device 110 via the Host IF 210.

  The access management information encryption / decryption unit 620 encrypts / decrypts various types of information transmitted / received between the SDC 200 and the SCC 300 using the encryption key Ks generated by the key generation unit 250.

  When data is written, the access management information encryption / decryption unit 620 encrypts the write data input from the session key encryption / decryption unit 610 using the encryption key Ks. Further, the access management information encryption / decryption unit 620 transmits the write data encrypted with the encryption key Ks to the SCC 300 via the SCC IF 640.

  The access management information encryption / decryption unit 620 decrypts the read data input from the SCC 300 using the encryption key Ks when reading the data. Also, the access management information encryption / decryption unit 620 outputs the decrypted read data to the session key encryption / decryption unit 610.

  The access management information encryption / decryption unit 620 decrypts the encrypted access management information corresponding to the area designated by the access area designation command transmitted from the SCC 300, using the encryption key Ks. The encrypted access management information includes information for specifying an area to be accessed in the flash memory 400 such as an area number, a physical address, an access length, an ID of an application that owns the area, and a session key Kss and its encryption algorithm. Is included.

  The access management information encryption / decryption unit 620 sets the decrypted session key Kss in the session key encryption / decryption unit 610. Further, the access management information encryption / decryption unit 620 sets information for specifying an area to be accessed in the flash memory 400 in the Flash IF 630.

  The Flash IF 630 transmits / receives various data to / from the flash memory 400. Specifically, the Flash IF 630 transmits write data to the flash memory 400 input from the SCC IF 640 to an area designated by the access area designation command of the flash memory 400. Further, the Flash IF 630 receives data read from the area specified by the access area specifying command of the flash memory 400. The Flash IF 630 transmits this read data to the SCC 300 via the SCC IF 640.

  The SCC IF 640 transmits / receives various data to / from the SCC 300. Specifically, the SCC IF 640 receives write data encrypted with the encryption key Ks input from the access management information encryption / decryption unit 620 and read data encrypted with the storage key Kst input from the Flash IF 630. It transmits to SCC300. The SCC IF 640 receives the write data encrypted with the storage key Kst transmitted from the SDC IF 670 of the SCC 300 and the read data encrypted with the encryption key Ks transmitted from the SDC IF 670 of the SCC 300. Also, the SCC IF 640 outputs the received write data to the Flash IF 630 and outputs the received read data to the access management information encryption / decryption unit 620.

  The SCC 300 of the memory card 600 includes an access management information encryption / decryption unit 650, a storage key encryption / decryption unit 660, and an SDC IF 670.

  The access management information encryption / decryption unit 650 encrypts / decrypts various types of information transmitted / received between the SDC 200 and the SCC 300 using the encryption key Ks generated by the key generation unit 320.

  When the access management information encryption / decryption unit 650 receives the access area designation command transmitted from the SDC 200, the access management information encryption / decryption section 650 acquires access management information corresponding to the access area designation command from the access management information held by the key storage unit 310. Also, the access management information encryption / decryption unit 650 sets the storage key Kst included in the acquired access management information in the storage key encryption / decryption unit 660.

  The access management information encryption / decryption unit 650 encrypts the access management information excluding the storage key Kst using the encryption key Ks. Further, the access management information encryption / decryption unit 650 transmits the encrypted access management information to the SDC 200 via the SDC IF 670.

  When writing data, the access management information encryption / decryption unit 650 uses the encryption key Ks to decrypt the write data encrypted from the SDC 200 and encrypted with the encryption key Ks. Also, the access management information encryption / decryption unit 650 outputs the decrypted write data to the storage key encryption / decryption unit 660.

  The access management information encryption / decryption unit 650 encrypts the read data input from the storage key encryption / decryption unit 660 using the encryption key Ks when reading the data. Further, the access management information encryption / decryption unit 650 transmits the read data encrypted with the encryption key Ks to the SDC 200 via the SDC IF 670.

  The storage key encryption / decryption unit 660 encrypts / decrypts data to be written to the flash memory 400 or data to be read from the flash memory 400 using the storage key Kst.

  The storage key encryption / decryption unit 660 encrypts the write data input from the access management information encryption / decryption unit 650 using the storage key Kst when writing data. In addition, the storage key encryption / decryption unit 660 transmits the write data encrypted with the storage key Kst to the SDC 200 via the SDC IF 670.

  When reading data, the storage key encryption / decryption unit 660 uses the storage key Kst to decrypt the read data from the SDC 200. Further, the storage key encryption / decryption unit 660 outputs the read data decrypted with the storage key to the access management information encryption / decryption unit 650.

  The SDC IF 670 transmits / receives various data to / from the SDC 200. Specifically, the SDC IF 670 is encrypted with the write data encrypted with the storage key Kst input from the storage key encryption / decryption unit 660 and the encryption key Ks input from the access management information encryption / decryption unit 650. Read data is transmitted to the SDC 200. The SDC IF 670 receives the write data encrypted with the encryption key Ks and the read data encrypted with the storage key Kst transmitted from the SCC IF 640 of the SDC 200. Also, the SDC IF 670 outputs the received write data to the access management information encryption / decryption unit 650 and outputs the received read data to the storage key encryption / decryption unit 660.

  Next, the operation of the memory card 600 configured as described above will be described in detail with reference to FIGS. Note that the mechanism of authentication and sharing of the encryption key Ks between the SDC 200 and the SCC 300 in the reset process is the same as that in the first embodiment, so that the description thereof is omitted, and the data write operation and security in the security protection area 420 are omitted. A data read operation from the protection area 420 will be described.

  FIG. 7 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when data is written to the security protection area 420 of the memory card 600. Here, a case where data is written to the area block 422 of the security protection area 420 will be described. For simplicity, it is assumed that the area block 422 corresponds to “area 2” of the access management information shown in FIG.

  In FIG. 7, data is written into the security protection area 420 in order to write various data corresponding to the area in which data is written, access area designation command processing (steps S41 to S47), and to actually write data. The data transfer command process (steps S48 to S54) is performed in two steps.

[Access area specification command processing]
First, access area designation command processing will be described.

  First, the host device 110 transmits an access area designation command in which an area number, a block address, and a block length for designating an area to be accessed are described to the SDC 200 (S41). The access area designation command received by the Host IF 210 of the SDC 200 is output to the SCC IF 640. Further, the SCC IF 640 further transmits the input access area designation command to the SCC 300 (S42). The access area designation command received by the SDC IF 670 of the SCC 300 is output to the access management information encryption / decryption unit 650.

  When the access management information encryption / decryption unit 650 receives the access area designation command, the access management information corresponding to the access area designation command, for example, the physical address of the area to be accessed, the access, from the access management information held by the key storage unit 310 The length, the session key Kss, and the storage key Kst are acquired (S43). In this example, the access management information encryption / decryption unit 650 acquires the physical address 0x00002000, access length, session key Kss2, and storage key Kst1 corresponding to the area block 422 (area 2) as access management information.

  The access management information encryption / decryption unit 650 uses the encryption key Ks generated by the key generation unit 320 to obtain the access management information acquired in step S43, that is, the physical address, access length, and session key Kss corresponding to the area block 422. Is encrypted. Further, the access management information encryption / decryption unit 650 transmits the encrypted access management information to the SDC 200 (S44). The encrypted access management information received by the SCC IF 640 of the SDC 200 is output to the access management information encryption / decryption unit 620.

  Further, the access management information encryption / decryption unit 650 sets the storage key Kst acquired in step S43, for example, Kst1, in the storage key encryption / decryption unit 660 (S45).

  The access management information encryption / decryption unit 620 of the SDC 200 decrypts the encrypted access management information from the SCC 300 using the encryption key Ks generated by the key generation unit 250. As a result, the access management information encryption / decryption unit 620 obtains the physical address 0x00002000, the access length, and the session key Kss2 corresponding to the access destination, that is, the area block 422 (S46).

  Then, the access management information encryption / decryption unit 620 sets the session key Kss2 acquired in step S46 in the session key encryption / decryption unit 610. Further, the access management information encryption / decryption unit 620 sets the physical address and access length acquired in step S46 in the Flash IF 630 (S47).

[Data transfer command processing]
Next, data transfer command processing will be described.

  First, the host device 110 encrypts data to be written in the area block 422 using the session key Kss, for example, the session key Kss2 (S48). Here, the host device 110 shares the session key Kss with the memory card 600 in advance. Further, for example, it is possible to share a session key by using a key exchange process such as Diffe-Helman.

  The host device 110 transmits a data transfer command for instructing data writing to the SDC 200 together with the write data encrypted with the session key Kss2 (S49). This write data received by the Host IF 210 of the SDC 200 is output to the session key encryption / decryption unit 610.

  The session key encryption / decryption unit 610 decrypts the write data from the host device 110 using the session key Kss2 set in step S47 (S50). The access management information encryption / decryption unit 620 encrypts the decrypted write data using the encryption key Ks generated by the key generation unit 250 (S51). Further, the access management information encryption / decryption unit 620 transmits the write data encrypted with the encryption key Ks to the SCC 300 via the SCC IF 640.

  Upon receiving the write data encrypted with the encryption key Ks from the SDC 200, the access management information encryption / decryption unit 650 of the SCC 300 decrypts the write data using the encryption key Ks generated by the key generation unit 320. (S52). Also, the access management information encryption / decryption unit 650 outputs the decrypted write data to the storage key encryption / decryption unit 660.

  The storage key encryption / decryption unit 660 encrypts the decrypted write data using the storage key Kst1 set in step S45 (S53). The storage key encryption / decryption unit 660 transmits the write data encrypted with the storage key Kst1 to the SDC 200 via the SDC IF 670. Then, the Flash IF 630 writes the write data encrypted with the storage key Kst1 in the area indicated by the physical address set in step S47, for example, the area block 422 (S54).

  The data write operation to the security protection area 420 of the flash memory 400 has been described above.

  Next, a data read operation from the security protection area 420 of the flash memory 400 will be described with reference to FIG.

  FIG. 8 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when data is read from the security protection area 420 of the memory card 600. Here, a case where data stored in the area block 422 of the security protection area 420 is read will be described. For simplicity, it is assumed that the area block 422 corresponds to “area 2” of the access management information shown in FIG.

  In FIG. 8, data is read from the security protection area 420 in order to set the various information corresponding to the data reading area (step S41 to step S47) and to actually read the data. The data acquisition command process (steps S61 to S68) is performed in two steps. The access area designation command process in FIG. 8 is the same as the above-mentioned access area designation command process in FIG.

[Data acquisition command processing]
First, the host device 110 transmits a data acquisition command for instructing data reading to the SDC 200 (S61). The data acquisition command received by the Host IF 210 of the SDC 200 is output to the Flash IF 630.

  The Flash IF 630 reads the data stored in the area indicated by the physical address set in step S47, for example, the area block 422 (S62). The read data is transmitted to the SCC 300 via the SCC IF 640 and further output to the stored key encryption / decryption unit 660.

  The storage key encryption / decryption unit 660 decrypts the data read from the area block 422 using the storage key Kst set in step S45, for example, the storage key Kst1 (S63). The decrypted read data is output to the access management information encryption / decryption unit 650. The access management information encryption / decryption unit 650 encrypts the decrypted read data using the encryption key Ks generated by the key generation unit 320 (S64). The access management information encryption / decryption unit 650 transmits the read data encrypted with the encryption key Ks to the SDC 200 via the SDC IF 670.

  When receiving the read data encrypted with the encryption key Ks from the SCC 300, the access management information encryption / decryption unit 620 of the SDC 200 decrypts the read data using the encryption key Ks generated by the key generation unit 250. (S65). The access management information encryption / decryption unit 620 outputs the decrypted read data to the session key encryption / decryption unit 610.

  The session key encryption / decryption unit 610 encrypts the decrypted read data using the session key Kss2 set in step S47 (S66). Then, the session key encryption / decryption unit 610 transmits the read data encrypted with the session key Kss2 to the host device 110 via the Host IF 210 (S67).

  The host device 110 acquires plaintext read data by decrypting the encrypted read data from the SDC 200 using the session key Kss2 (S68).

  The operation for reading data from the security protection area 420 of the flash memory 400 has been described above.

  Thus, according to the present embodiment, since the SCC 300 performs encryption / decryption of the access data to the security protection area 420 using the storage key Kst, the security and reliability of encryption / decryption using the storage key Kst are improved. be able to.

  In addition, since the SDC 200 and the SCC 300 encrypt the write data or read data to be transmitted / received with the encryption key Ks shared between the SDC 200 and the SCC 300, the confidentiality of the communication path between the SDC 200 and the SCC 300 is improved. be able to.

(Embodiment 3)
In the present embodiment, encryption / decryption processing of data transmitted to / from the host device 110 is performed by the session key encryption / decryption unit 770 provided in the SCC 300 and encryption / decryption of data transmitted to / from the flash memory 400 is performed. A memory card 700 configured so that the storage key encryption / decryption unit 720 provided in the SDC 200 performs processing will be described.

  FIG. 9 is a block diagram showing a configuration of a memory card 700 according to Embodiment 3 of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and description of overlapping portions is omitted. Further, only the additional functions of the components having additional functions in the components of FIG. 1 will be described.

  9, the SDC 200 of the memory card 700 includes a Host IF 710, a storage key encryption / decryption unit 720, an access management information encryption / decryption unit 730, a Flash IF 740, and an SCC IF 750.

  The Host IF 710 transmits / receives various data to / from the host device 110. Specifically, the Host IF 710 receives the write data encrypted with the session key Kss transmitted from the host device 110, and transmits it to the SCC 300 via the SCC IF 750. Further, the Host IF 710 transmits read data encrypted with the session key Kss input from the SCC IF 750 to the host device 110.

  The storage key encryption / decryption unit 720 encrypts / decrypts data to be written to the flash memory 400 or data to be read from the flash memory 400 using the storage key Kst.

  The storage key encryption / decryption unit 720 encrypts the write data input from the access management information encryption / decryption unit 730 using the storage key Kst when writing data. In addition, the storage key encryption / decryption unit 720 transmits the write data encrypted by the storage key Kst to the area specified by the access area specification command of the flash memory 400 via the Flash IF 740.

  When reading data, the storage key encryption / decryption unit 720 uses the storage key Kst to decrypt data read from the area specified by the access area specification command of the flash memory 400. Also, the storage key encryption / decryption unit 720 outputs the read data decrypted with the storage key Kst to the access management information encryption / decryption unit 730.

  The access management information encryption / decryption unit 730 uses the encryption key Ks generated by the key generation unit 250 to encrypt / decrypt various information transmitted / received between the SDC 200 and the SCC 300.

  The access management information encryption / decryption unit 730 decrypts the write data transmitted from the SCC 300 using the encryption key Ks when writing data. Further, the access management information encryption / decryption unit 730 outputs the decrypted write data to the storage key encryption / decryption unit 720.

  The access management information encryption / decryption unit 730 encrypts the read data input from the storage key encryption / decryption unit 720 using the encryption key Ks when reading the data. Further, the access management information encryption / decryption unit 730 transmits the encrypted read data to the SCC 300 via the SCC IF 750.

  The access management information encryption / decryption unit 730 uses the encryption key Ks to decrypt the encrypted access management information corresponding to the area designated by the access area designation command transmitted from the SCC 300. The encrypted access management information includes information for specifying an area to be accessed in the flash memory 400 such as an area number, a physical address, an access length, an ID of an application that owns the area, and a storage key Kst and its encryption algorithm. Is included.

  The access management information encryption / decryption unit 730 sets the decrypted storage key Kst in the storage key encryption / decryption unit 720. Further, the access management information encryption / decryption unit 730 sets information for specifying an area to be accessed in the flash memory 400 in the Flash IF 740.

  The Flash IF 740 transmits / receives various data to / from the flash memory 400. Specifically, the Flash IF 740 transmits the write data to the flash memory 400 input from the storage key encryption / decryption unit 720 to the area designated by the access area designation command of the flash memory 400. In addition, the Flash IF 740 receives data read from the area specified by the access area specifying command of the flash memory 400. The Flash IF 740 outputs the read data to the stored key encryption / decryption unit 720.

  The SCC IF 750 transmits / receives various data to / from the SCC 300. Specifically, the SCC IF 750 encrypts the write data encrypted with the session key Kss received from the host device 110 via the Host IF 710 and the encryption key Ks input from the access management information encryption / decryption unit 730. The read data that has been read is transmitted to the SCC 300. Further, the SCC IF 750 receives the write data encrypted with the encryption key Ks transmitted from the SDC IF 780 of the SCC 300 and the read data encrypted with the session key Kss. In addition, the SCC IF 740 outputs the received write data to the access management information encryption / decryption unit 730 and transmits the received read data to the host device 110 via the Host IF 710.

  The SCC 300 of the memory card 700 includes an access management information encryption / decryption unit 760, a session key encryption / decryption unit 770, and an SDC IF 780.

  The access management information encryption / decryption unit 760 uses the encryption key Ks generated by the key generation unit 320 to encrypt / decrypt various information transmitted / received between the SDC 200 and the SCC 300.

  When receiving the access area designation command transmitted from the SDC 200, the access management information encryption / decryption section 760 acquires access management information corresponding to the access area designation command from the access management information held by the key storage section 310. Further, the access management information encryption / decryption unit 760 sets the session key Kss included in the acquired access management information in the session key encryption / decryption unit 770.

  The access management information encryption / decryption unit 760 encrypts the access management information excluding the session key Kss using the encryption key Ks. Further, the access management information encryption / decryption unit 760 transmits the encrypted access management information to the SDC 200 via the SDC IF 780.

  When data is written, the access management information encryption / decryption unit 760 encrypts the write data input from the session key encryption / decryption unit 770 using the encryption key Ks. Further, the access management information encryption / decryption unit 760 transmits the encrypted write data to the SDC 200 via the SDC IF 780.

  The access management information encryption / decryption unit 760 decrypts the read data transmitted from the SDC 200 by using the encryption key Ks when reading the data. Also, the access management information encryption / decryption unit 760 outputs the decrypted read data to the session key encryption / decryption unit 770.

  The session key encryption / decryption unit 770 encrypts / decrypts data transmitted / received to / from the host device 110 using the session key Kss.

  When writing data, session key encryption / decryption unit 770 decrypts the write data to flash memory 400 transmitted from SDC 200 with session key Kss. The session key encryption / decryption unit 770 outputs the decrypted write data to the access management information encryption / decryption unit 760.

  When reading data, the session key encryption / decryption unit 770 encrypts the read data from the flash memory 400 input from the access management information encryption / decryption unit 760 with the session key Kss. The session key encryption / decryption unit 770 transmits the encrypted read data to the SDC 200 via the SDC IF 780.

  The SDC IF 780 transmits / receives various data to / from the SDC 200. Specifically, the SDC IF 780 is encrypted with the write data encrypted with the encryption key Ks input from the access management information encryption / decryption unit 760 and the session key Kss input from the session key encryption / decryption unit 770. Read data is transmitted to the SDC 200. Further, the SDC IF 780 receives the write data encrypted with the session key Kss and the read data encrypted with the encryption key Ks transmitted from the SCC IF 750 of the SDC 200. Also, the SDC IF 780 outputs the received write data to the session key encryption / decryption unit 770 and outputs the received read data to the access management information encryption / decryption unit 760.

  Next, the operation of the memory card 700 configured as described above will be described in detail with reference to FIGS. Note that the mechanism of authentication and sharing of the encryption key Ks between the SDC 200 and the SCC 300 in the reset process is the same as that in the first embodiment, so that the description thereof is omitted, and the data write operation and security in the security protection area 420 are omitted. A data read operation from the protection area 420 will be described.

  FIG. 10 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when data is written to the security protection area 420 of the memory card 700. Here, a case where data is written to the area block 422 of the security protection area 420 will be described. For simplicity, it is assumed that the area block 422 corresponds to “area 2” of the access management information shown in FIG.

  In FIG. 10, data is written to the security protection area 420 in order to write various data corresponding to the data writing area (steps S71 to S77) and to actually write the data. The data transfer command process (steps S78 to S84) is performed in two steps.

[Access area specification command processing]
First, access area designation command processing will be described.

  First, the host device 110 transmits an access area designation command in which an area number, a block address, and a block length for designating an area to be accessed are described to the SDC 200 (S71). The access area designation command received by the Host IF 710 of the SDC 200 is output to the SCC IF 750. Further, the SCC IF 750 further transmits the input access area designation command to the SCC 300 (S72). The access area designation command received by the SDC IF 780 of the SCC 300 is output to the access management information encryption / decryption unit 760.

  When the access management information encryption / decryption unit 760 receives the access area designation command, the access management information corresponding to the access area designation command, for example, the physical address of the area to be accessed, the access, from the access management information held by the key storage unit 310 The length, the session key Kss, and the storage key Kst are acquired (S73). In this example, the access management information encryption / decryption unit 760 acquires the physical address 0x00002000, access length, session key Kss2, and storage key Kst1 corresponding to the area block 422 (area 2) as access management information.

  The access management information encryption / decryption unit 760 uses the encryption key Ks generated by the key generation unit 320 to access the access management information acquired in step S73, that is, the physical address corresponding to the area block 422, the access length, and the storage key Kst. Is encrypted. Further, the access management information encryption / decryption unit 760 transmits the encrypted access management information to the SDC 200 (S74). The encrypted access management information received by the SCC IF 750 of the SDC 200 is output to the access management information encryption / decryption unit 730.

  Further, the access management information encryption / decryption unit 760 sets the session key Kss, for example, Kss2, acquired in step S73, in the session key encryption / decryption unit 770 (S75).

  The access management information encryption / decryption unit 730 of the SDC 200 decrypts the encrypted access management information from the SCC 300 using the encryption key Ks generated by the key generation unit 250. As a result, the access management information encryption / decryption unit 730 acquires the physical address 0x00002000, the access length, and the storage key Kst1 corresponding to the access destination, that is, the area block 422 (S76).

  Then, the access management information encryption / decryption unit 730 sets the storage key Kst1 acquired in step S76 in the storage key encryption / decryption unit 720. Further, the access management information encryption / decryption unit 730 sets the physical address and access length acquired in step S76 in the Flash IF 740 (S77).

[Data transfer command processing]
Next, data transfer command processing will be described.

  First, the host device 110 encrypts data to be written in the area block 422 using the session key Kss, for example, the session key Kss2 (S78). Here, the host device 110 shares the session key Kss with the memory card 700 in advance. Further, for example, it is possible to share a session key by using a key exchange process such as Diffe-Helman.

  In addition, the host device 110 transmits to the SDC 200 a data transfer command instructing data writing together with the write data encrypted by the session key Kss2 (S79). This write data received by the Host IF 710 of the SDC 200 is transmitted to the SCC 300 via the SCC IF 750. Further, the write data received by the SDC IF 780 of the SCC 300 is output to the session key encryption / decryption unit 770.

  The session key encryption / decryption unit 770 decrypts the write data from the SDC 200 using the session key Kss2 set in step S75 (S80). The access management information encryption / decryption unit 760 encrypts the decrypted write data using the encryption key Ks generated by the key generation unit 320 (S81). Also, the access management information encryption / decryption unit 760 transmits the write data encrypted with the encryption key Ks to the SDC 200 via the SDC IF 780.

  Upon receiving the write data encrypted with the encryption key Ks from the SCC 300, the access management information encryption / decryption unit 730 of the SDC 200 decrypts the write data using the encryption key Ks generated by the key generation unit 250. (S82). Further, the access management information encryption / decryption unit 730 outputs the decrypted write data to the storage key encryption / decryption unit 720.

  The storage key encryption / decryption unit 720 encrypts the decrypted write data using the storage key Kst1 set in step S77 (S83). In addition, the storage key encryption / decryption unit 720 outputs the write data encrypted with the storage key Kst1 to the Flash IF 740. Then, the Flash IF 740 writes the write data encrypted with the storage key Kst1 in the area indicated by the physical address set in step S77, for example, the area block 422 (S84).

  The data write operation to the security protection area 420 of the flash memory 400 has been described above.

  Next, a data read operation from the security protection area 420 of the flash memory 400 will be described with reference to FIG.

  FIG. 11 is a sequence diagram illustrating an example of operations of the host device 110, the SDC 200, and the SCC 300 when reading data from the security protection area 420 of the memory card 700. Here, a case where data stored in the area block 422 of the security protection area 420 is read will be described. For simplicity, it is assumed that the area block 422 corresponds to “area 2” of the access management information shown in FIG.

  In FIG. 11, data is read from the security protection area 420 in order to set various information corresponding to the data reading area (steps S71 to S77) and to actually read the data. The data acquisition command processing (steps S91 to S98) is performed in two steps. The access area designation command process in FIG. 11 is the same as the above-described access area designation command process in FIG.

[Data acquisition command processing]
First, the host device 110 transmits a data acquisition command for instructing data reading to the SDC 200 (S91). The data acquisition command received by the Host IF 710 of the SDC 200 is output to the Flash IF 740.

  The Flash IF 740 reads the data stored in the area indicated by the physical address set in step S77, for example, the area block 422 (S92). Further, the Flash IF 740 outputs the read data to the storage key encryption / decryption unit 720.

  The storage key encryption / decryption unit 720 decrypts the data read from the area block 422 using the storage key Kst set in step S77, for example, the storage key Kst1 (S93). The decrypted read data is output to the access management information encryption / decryption unit 730. The access management information encryption / decryption unit 730 encrypts the decrypted read data using the encryption key Ks generated by the key generation unit 250 (S94). Further, the access management information encryption / decryption unit 730 transmits the read data encrypted with the encryption key Ks to the SCC 300 via the SCC IF 750.

  When receiving the read data encrypted with the encryption key Ks from the SDC 200, the access management information encryption / decryption unit 760 of the SCC 300 decrypts the read data using the encryption key Ks generated by the key generation 320 ( S95). Also, the access management information encryption / decryption unit 760 outputs the decrypted read data to the session key encryption / decryption unit 770.

  The session key encryption / decryption unit 770 encrypts the decrypted read data using the session key Kss2 set in step S75 (S96). In addition, the session key encryption / decryption unit 770 transmits the read data encrypted with the session key Kss2 to the SDC 200 via the SDC IF 780. Then, the SCC IF 750 receives this read data and transmits it to the host device 110 via the Host IF 710 (S97).

  The host device 110 acquires plaintext read data by decrypting the encrypted read data from the SDC 200 using the session key Kss2 (S98).

  The operation for reading data from the security protection area 420 of the flash memory 400 has been described above.

  As described above, according to the present embodiment, since the SCC 300 performs encryption / decryption with the session key Kss of the data transmitted / received to / from the host device 110, the encryption / decryption with the session key Kss can be performed safely and reliably. Can be improved.

  The memory card according to the present invention has the effect of being able to access the security protection area at high speed without reducing the security strength, and is useful as a memory card for performing security processing such as personal authentication and protection of confidential information. .

The block diagram which shows the structure of the memory card based on Embodiment 1 of this invention. The figure which shows an example of access management information The sequence diagram which shows an example of operation | movement of a host apparatus, SDC, and SCC in the case of producing | generating encryption key Ks by reset processing The sequence diagram which shows an example of operation | movement of a host apparatus, SDC, and SCC in the case of writing data in the security protection area | region of the memory card of FIG. The sequence diagram which shows an example of operation | movement of a host apparatus, SDC, and SCC in the case of reading data from the security protection area | region of the memory card of FIG. The block diagram which shows the structure of the memory card based on Embodiment 2 of this invention. FIG. 6 is a sequence diagram showing an example of operations of the host device, SDC, and SCC when data is written to the security protection area of the memory card of FIG. FIG. 6 is a sequence diagram showing an example of operations of the host device, SDC, and SCC when data is read from the security protection area of the memory card of FIG. The block diagram which shows the structure of the memory card based on Embodiment 3 of this invention. FIG. 9 is a sequence diagram showing an example of operations of the host device, SDC, and SCC when data is written to the security protection area of the memory card of FIG. FIG. 9 is a sequence diagram showing an example of operations of the host device, SDC, and SCC when data is read from the security protection area of the memory card of FIG. The figure which shows the procedure for accessing the security protection area in the conventional memory card

Explanation of symbols

100, 600, 700 Memory card 110 Host device 200 SD controller chip 210, 710 Host IF
220, 610, 770 Session key encryption / decryption unit 230, 660, 720 Storage key encryption / decryption unit 240, 630, 740 Flash IF
250, 320 Key generation unit 260 Access management information decryption unit 270, 640, 750 SCC IF
300 Smart card chip 310 Key storage unit 330 Access management information encryption unit 340, 670, 780 SDC IF
400 Flash memory 410 Normal area 420 Security protection area 500 Access management information 620, 650, 730, 760 Access management information encryption / decryption unit

Claims (11)

In a memory card provided with a smart card chip that executes writing of data to the memory chip or reading of data from the memory chip, and a controller chip that controls writing or reading of data executed by the smart card chip,
A first encryption / decryption unit for performing encryption / decryption processing on data transmitted between the memory card and an external device;
A second encryption / decryption unit for performing encryption / decryption processing on data transmitted between the memory chip and the smart card chip,
At least one of the first encryption / decryption unit and the second encryption / decryption unit is provided in the controller chip,
A memory card characterized by that. The first encryption / decryption unit and the second encryption / decryption unit are provided in the controller chip,
The memory card according to claim 1. A key storage unit that holds a session key used by the first encryption / decryption unit for encryption / decryption processing and a storage key used by the second encryption / decryption unit for encryption / decryption processing;
The key storage unit is provided in the smart card chip.
The memory card according to claim 2. A security key encryption unit that encrypts the session key and the storage key held by the key storage unit;
A security key decryption unit for decrypting the session key and the storage key encrypted by the security key encryption unit,
The security key encryption unit is provided in the smart card chip,
The security key decryption unit is provided in the controller chip;
The memory card according to claim 3. An encrypted security key generation unit for generating a security key used for encryption by the security key encryption unit;
The security key decryption unit further comprises a decryption security key generation unit that generates a security key used for decryption,
The encrypted security key generation unit is provided in the smart card chip,
The decryption security key generation unit is provided in the controller chip.
The memory card according to claim 4. The encryption security key generation unit and the decryption security key generation unit are:
Upon receiving a reset command from the external device, the security key encryption unit and the security key decryption unit newly generate a security key used for encryption / decryption processing,
6. The memory card according to claim 5, wherein: The memory chip is provided with a security protection area for storing security information divided into a plurality of logical areas.
The memory card according to claim 3. The key storage unit
Holding the session key and the storage key in association with each of the divided areas of the security protection area;
The memory card according to claim 7. The first encryption / decryption unit is provided in the controller chip,
The second encryption / decryption unit is provided in the smart card chip.
The memory card according to claim 1. The first encryption / decryption unit is provided in the smart card chip,
The second encryption / decryption unit is provided in the controller chip.
The memory card according to claim 1. A data transmission step for executing writing of data to the memory chip or reading of data from the memory chip by the smart card chip, and a control step for controlling writing or reading of the data executed by the data transmission step by the controller chip A method of accessing a memory chip of a memory card comprising:
A first encryption / decryption step of encrypting / decrypting data transmitted between the memory card and an external device;
A second encryption / decryption step for performing encryption / decryption processing on data transmitted between the memory chip and the smart card chip,
At least one of the first encryption / decryption step and the second encryption / decryption step is executed by the controller chip;
A method for accessing a memory chip of a memory card.

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