JP5908869B2 - Communication device - Google Patents

Description

  The present invention relates to a communication device. Specifically, the present invention relates to a technique for reading or writing data from / to a communication device from a reader / writer.

  In a communication system such as a conventional IC card system, in order for a reader / writer to perform encrypted communication and securely read / write data in a communication apparatus, mutual authentication is performed for each communication session to generate an encryption key. (For example, see Patent Document 1 and Patent Document 2). According to this method, a random number is generated by the random number generation means of each of the first and second information processing apparatuses, the encrypted random number is exchanged using a preset key, and this is correctly decrypted. Authentication was performed based on whether or not it was possible.

JP 2005-27338 A Japanese Patent Laid-Open No. 10-20780

  However, this method based on mutual authentication is used to prevent eavesdropping and spoofing by the third information processing apparatus, but the random numbers of the first and second information processing apparatuses are independent of the application. It is premised on generation and encryption and transmission of random numbers. For this reason, the efficiency is low and processing time is required.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable a reader / writer to read or write data stored in a communication device at high speed while maintaining safety. It is to provide a new and improved technique that can be performed.

  In order to achieve the above object, according to an aspect of the present invention, a communication unit that transmits / receives a signal to / from a reader / writer and data are recorded and used in common with the reader / writer. An encryption key update request signal including an encryption key encrypted with the same key as the common key recorded in the recording unit by the recording unit in which the common key as a key is recorded, and the communication unit from the reader / writer to the communication unit The encrypted encryption key included in the encryption key update request signal is decrypted with the common key recorded in the recording unit, the decrypted encryption key is recorded in the recording unit, and the reader / writer When a read request signal including a read target address that specifies a data read source area in the recording unit, encrypted with the same encryption key as the encryption key, is received from the reader / writer via the communication unit The encrypted read target address included in the solicitation signal is decrypted with the encryption key recorded in the recording unit, and the data recorded in the area specified by the read target address obtained by decryption in the recording unit area Is provided to the reader / writer via the communication unit.

  In order to solve the above-described problem, according to another aspect of the present invention, a communication unit that transmits and receives signals to and from a reader / writer and data are recorded and shared between the reader and writer. When a recording unit in which a common key, which is a key to be used, is recorded, and an encryption key generation request signal indicating that generation of an encryption key is requested from the reader / writer via the communication unit, the encryption key is transmitted in a predetermined procedure. The generated encryption key is encrypted with the common key recorded in the recording unit, and an encryption key generation response signal including the encrypted encryption key is transmitted to the reader / writer via the communication unit. When the write request signal including the write target data that is encrypted and the write target address that specifies the write destination area of the write target data in the encrypted recording unit is received via the communication unit, the data is encrypted. The write target data and the encrypted write target address are decrypted with the encryption key recorded in the recording unit, and are decrypted into the region specified by the write target address obtained by decryption in the recording unit region. And a control unit that records the write target data.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the technique which reader / writer can read or write at high speed, maintaining safety | security with respect to the data which a communication apparatus has.

It is a sequence diagram which shows the authentication process at the time of the data reading in a general communication system. It is a sequence diagram which shows the authentication process at the time of the data writing in a general communication system. It is a figure which shows the structure of the communication system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the function of the reader / writer which concerns on embodiment of this invention. It is a block diagram which shows the structure of the function of the communication apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the data used when the communication system which concerns on embodiment of this invention reads data. It is a sequence diagram which shows the flow of a process at the time of the data reading by the communication system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the data used when the communication system which concerns on embodiment of this invention writes data. It is a sequence diagram which shows the flow of the process at the time of the data writing by the communication system which concerns on embodiment of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 1 is a sequence diagram showing an authentication process when reading data in a general communication system. An authentication process at the time of data reading in a general communication system will be described with reference to FIG.

  The authentication process is defined by ISO / IEC (International Organization for Standardization / International Electrotechnical Commission) 9798-2 and JIS (Japan Industrial Standards) X5056-2, a symmetric algorithm defined by a symmetric algorithm. Is.

  Here, first, in step S11, the reader / writer 11A generates a first random number A, encrypts it with a predetermined procedure using a common key B as an authentication key, and obtains encrypted data M1. M1 is transmitted to the communication device 12A as a parameter of Auth1_Req. Receiving Auth1_Req, the communication device 12A decrypts M1 of the parameter of Auth1_Req in a predetermined procedure using the common key B in step S21, and obtains a random number A. Subsequently, the random number A is encrypted by a predetermined procedure using the common key A to obtain encrypted data M2.

  Further, in step S22, a second random number B is generated and encrypted using a common key A in a predetermined procedure to obtain encrypted data M3. M2 and M3 are returned as parameters of Auth1_Res from the communication device 12A to the reader / writer 11A.

  The reader / writer 11A that has received Auth1_Res decrypts M2 of the Auth1_Res parameter using a common key A in a predetermined procedure in step S12, and the obtained value is the same value as the random number A generated in step S11. Compare and confirm. If it can be confirmed, the reader / writer 11A knows that the communication device 12A has the same common keys A and B as the reader / writer 11A.

  Subsequently, the reader / writer 11A decrypts the parameter M3 of Auth1_Res in a predetermined procedure using the common key A in step S13 to obtain a random number B. Subsequently, the random number B is encrypted by a predetermined procedure using the common key B to obtain encrypted data M4. M4 transmits to the communication device 12A as a parameter of Auth2_Req.

  The communication device 12A that has received Auth2_Req decrypts M4 of the parameter of Auth2_Req in a predetermined procedure using the common key B in step S23, and the obtained value is the same value as the random number B generated in step S22. Compare and confirm. If it can be confirmed, it can be seen that the communication device 12A has the same common keys A and B as the reader / writer 11A.

  Thereafter, the communication device 12A generates an encryption key (SK) for encrypting / decrypting the communication path and a session ID (SID) for identifying the mutual authentication process from the obtained random numbers A and B by a predetermined procedure. . Then, the session ID and the code indicating that the mutual authentication is successful are encrypted by a predetermined procedure using the encryption key SK, and the encrypted data M5 is obtained. M5 is returned as a parameter of Auth2_Res from the communication apparatus 12A to the reader / writer 11A.

  In step S14, the reader / writer 11A that has received Auth2_Res identifies the encryption key SK and the mutual authentication process for encrypting / decrypting the communication path from the random numbers A and B obtained so far by a predetermined procedure. An ID (SID) is generated. Next, the authentication process is completed by decrypting M2 of the parameter of Auth2_Res in a predetermined procedure using the encryption key SK and confirming that the same session ID and a code indicating that the mutual authentication is successful are obtained. .

  After completing the authentication process, the cryptographic communication process can be executed. In FIG. 1, after the authentication process, the data read request Read_Req from the communication device 12A is encrypted and transmitted. Read_Req is defined as a configuration including, for example, a request identifier and a read target address (see FIG. 6A). In step S15, all fields except the Read_Req request identifier are encrypted by a predetermined procedure using the encryption key SK shared in the mutual authentication process, and transmitted to the communication device 12A.

  In step S24, the communication device 12A that has received the Read_Req decrypts all fields except the request identifier of the Read_Req with the encryption key SK shared in the mutual authentication process in a predetermined procedure in the same manner as S15, and reads the plaintext Read_Req. obtain. The communication device 12A reads the data from the specified address according to the plaintext Read_Req and uses it as the parameter of Read_Res. Read_Res is defined as a configuration including, for example, a response identifier, a result code, and data to be read (see FIG. 6B). Similarly to Read_Req, Read_Res is also encrypted by the communication device 12A using the encryption key SK shared by the mutual authentication process, except for the response identifier, and returned from the communication device 12A to the reader / writer 11A.

  FIG. 2 is a sequence diagram showing an authentication process at the time of data writing in a general communication system. With reference to FIG. 2, an authentication process at the time of data writing in a general communication system will be described.

  In FIG. 2, after the authentication process equivalent to that in FIG. 1, the data write request Write_Req to the communication device 12A is encrypted and transmitted. Write_Req is defined as a configuration including, for example, a request identifier, a write target address, and write target data (see FIG. 8A).

  In step S35, all fields except the request identifier of Write_Req are encrypted by a predetermined procedure using the encryption key SK shared in the mutual authentication process, and transmitted to the communication device 12A.

  In step S44, the communication device 12A that has received the Write_Req decrypts all fields except for the request identifier of the Write_Req with the encryption key SK shared in the mutual authentication process in a predetermined procedure, and performs plain text Write_Req. obtain. The communication device 12A writes the designated data to the designated address in accordance with the plain text Write_Req, and uses the result code as the parameter of Write_Res. Write_Res is defined as, for example, a configuration including a response identifier and a result code (see FIG. 8B). Similarly to Write_Req, Write_Res is also encrypted by the communication device 12A using the encryption key SK shared by the mutual authentication process, except for the response identifier, and returned from the communication device 12A to the reader / writer 11A.

  FIG. 3 is a diagram showing a configuration of a communication system according to the embodiment of the present invention. A communication system according to an embodiment of the present invention will be described with reference to FIG.

  As illustrated in FIG. 3, the communication system 10 includes a reader / writer 11 and a communication device 12 that perform wireless communication. The reader / writer 11 and the communication device 12 transmit and receive data in a contactless manner using electromagnetic waves. Is done. The general wireless communication system assumed here performs encrypted communication according to the following procedure.

  The reader / writer 11 emits radio waves (electromagnetic waves) and detects the communication device 12 by performing processing such as polling, for example. When the communication device 12 approaches the reader / writer 11 and the reader / writer 11 detects the communication device 12, the reader / writer 11 and the communication device 12 perform an authentication process by transmitting and receiving predetermined data. Then, the reader / writer 11 encrypts and transmits a request signal to the communication device 12 using the encryption key and session ID generated / shared during the authentication process. The request signal includes, for example, a request signal for requesting overwriting of predetermined data, a request signal for requesting transmission of predetermined data, and the like.

  When the communication device 12 receives the request signal transmitted from the reader / writer 11, the communication device 12 decrypts the request signal using the shared encryption key, confirms the consistency with the shared session ID, and is requested. And return a code indicating the success or failure.

  In the present embodiment, the command sequence is optimized for the usage method by separating and independently authenticating each authentication process in secure data reading / writing with respect to the communication device 12 that is a security device. When performing read processing from the security device, the side that performs the read request generates an encryption key (session key) and transmits it to the read side. Subsequently, the read side uses this encryption key (session key) to encrypt the read data and transmit it. When performing a writing process from the security device, an encryption key (session key) is generated from the writing side and transmitted to the writing requesting side. Subsequently, the writing side encrypts and transmits the write data using the encryption key (session key). As a result, it is possible to update the authentication or the session key for the communication device 12 as a security device at a higher speed.

  In this method, in order to transmit the encryption key (session key) in a secret manner, a common key shared between the security devices (between the reader / writer 11 and the communication device 12) is used, and the encryption key (session key) is used. Is encrypted.

  By using different session keys or common keys for the read process and the write process for the data area of the communication device 12, a system with separate access authorities can be realized.

  FIG. 4 is a block diagram showing a functional configuration of the reader / writer according to the embodiment of the present invention. A reader / writer according to an embodiment of the present invention will be described with reference to FIG.

  The reader / writer 11 includes a control unit 31, a recording unit (second recording unit) 32, an SPU (Signal Processing Unit) 33, a modulation unit 34, an oscillation circuit 35, an antenna 36 as an example of a communication unit, a demodulation unit 37, and a drive 38.

  The control unit 31 generates a request signal for requesting overwriting of data including predetermined data. Further, the control unit 31 generates a request signal for requesting transmission of predetermined data.

  The control unit 31 generates data to be stored in a request signal for requesting overwriting of data. When reading data, the control unit 31 generates an encryption key according to a predetermined procedure. The control unit 31 encrypts the generated encryption key with the read common key recorded in the recording unit 32, and sends an encryption key update request signal (see FIG. 6C) including the encrypted encryption key to the SPU 33. To supply. The encryption key update request signal is transmitted to the communication device 12 via the antenna 36. The control unit 31 encrypts a read target address that designates a data read source area in the nonvolatile memory 106 (see FIG. 5) with the generated encryption key, and reads a read request signal including the encrypted read target address (FIG. 6). (See (a)) is supplied to the SPU 33. The read request signal is transmitted to the communication device 12 via the antenna 36.

  When writing data, the control unit 31 supplies the SPU 33 with an encryption key generation request signal (see FIG. 8C) indicating that an encryption key generation is requested. The encryption key generation request signal is transmitted to the communication device 12 via the antenna 36. The control unit 31 receives an encryption key generation response signal (see FIG. 8D) including an encryption key encrypted by the communication device 12 using the same key as the writing common key recorded in the recording unit 32. 12 is received from the antenna 36 via the antenna 36 and supplied from the SPU 33, the control unit 31 uses the write common key recorded in the recording unit 32 to convert the encrypted encryption key included in the encryption key generation response signal. The encryption key obtained by decryption and decryption is recorded in the recording unit 32, and the write target data and the write target address designating the write destination area of the write target data in the nonvolatile memory 106 are recorded in the recording unit 32. Encrypted with the encryption key and supplied to the SPU 33 with a write request signal (see FIG. 8A) including the encrypted write target data and the encrypted write target address That. The write request signal is transmitted to the communication device 12 via the antenna 36.

  The control unit 31 is configured by, for example, a CPU (Central Processing Unit) and the like, reads a program supplied from the drive 38 that is mounted as necessary, and executes the read program. Further, when a program or data is supplied from the drive 38, the control unit 31 supplies the supplied program or data to the recording unit 32 as necessary, and reads and reads the program recorded in the recording unit 32. Run the program.

  The recording unit 32 is composed of a so-called non-volatile storage medium or recording medium that can be rewritten and can retain recorded contents even when the power is cut off, and is configured by, for example, a hard disk or a flash memory. The recording unit 32 records various data. The recording unit 32 supplies the recorded data to the control unit 31 as necessary.

  The recording unit 32 records at least one of a reading common key and a writing common key as a key used in common with the communication device 12. The recording unit 32 supplies the recorded common key to the control unit 31. The recording unit 32 records data supplied from the control unit 31.

  The SPU 33 encodes the request signal supplied from the control unit 31 by a predetermined method, and supplies the encoded request signal to the modulation unit 34. In addition, the SPU 33 decodes the response signal supplied from the demodulation unit 37 by a method corresponding to the response signal encoding method, and supplies the decoded response signal to the control unit 31.

  For example, when a request signal to be transmitted to the communication device 12 is supplied from the control unit 31, the SPU 33 performs an encoding process such as coding on a Manchester code on the request signal, and is thus obtained. The signal is output to the modulation unit 34. In addition, when the response signal from the communication device 12 is supplied from the demodulator 37, the SPU 33 performs a decoding process such as Manchester code decoding on the data, and the signal obtained thereby is It supplies to the control part 31.

  The modulation unit 34 generates a carrier wave based on a clock signal having a predetermined frequency supplied from the oscillation circuit 35. The modulating unit 34 generates a request signal by modulating the request signal supplied from the SPU 33 based on a carrier wave by a predetermined method, and supplies the modulated request signal to the antenna 36. For example, the modulation unit 34 generates a modulated request signal by changing the phase, amplitude, frequency, etc. of the carrier wave based on the request signal supplied from the SPU 33.

  More specifically, for example, the modulation unit 34 generates the ASK (Amplitude Shift Keying) modulation of the data supplied from the SPU 33 using the 13.56 MHz frequency clock signal supplied from the oscillation circuit 35 as a carrier wave. The modulated wave is output from the antenna 36 as an electromagnetic wave.

  The oscillation circuit 35 generates a reference clock signal having a predetermined frequency, and supplies the generated clock signal to the modulation unit 34.

  The antenna 36 transmits the request signal supplied from the modulation unit 34 to the communication device 12 by wireless communication. That is, for example, the antenna 36 radiates (radiates) a radio wave for transmitting the request signal supplied from the modulation unit 34. The antenna 36 receives the response signal transmitted from the communication device 12 and supplies the received response signal to the demodulation unit 37.

  The demodulation unit 37 demodulates the response signal supplied from the antenna 36 by a demodulation method corresponding to the modulation method of the modulation unit 109 (FIG. 3), and supplies the demodulated response signal to the SPU 33. For example, the demodulator 37 demodulates the modulated wave (ASK modulated wave) acquired via the antenna 36 and outputs the demodulated response signal to the SPU 33.

  When the magnetic disk 71, the optical disk 72, the magneto-optical disk 73, or the semiconductor memory 74 is mounted, the drive 38 drives them and acquires programs and data recorded therein. The acquired program and data are transferred to the control unit 31 or the communication device 12. The program transferred (transmitted) to the communication device 12 is recorded or executed by the communication device 12 as necessary.

  FIG. 5 is a block diagram showing a functional configuration of the communication apparatus according to the embodiment of the present invention. A communication apparatus according to an embodiment of the present invention will be described with reference to FIG.

  The communication device 12 includes an antenna 101, a demodulation unit 102, an SPU 103, a control unit 104, a recording unit (first recording unit) 106, a RAM (Random Access Memory) 107, an oscillation circuit 108, a modulation unit 109, as an example of a communication unit. And a power generation unit 110.

  The antenna 101 receives the request signal transmitted from the reader / writer 11 and supplies the received request signal to the demodulation unit 102. The antenna 101 transmits the response signal supplied from the modulation unit 109 to the reader / writer 11 by wireless communication. That is, for example, the antenna 101 radiates a radio wave for transmitting the response signal supplied from the modulation unit 109. In the antenna 101, resonance occurs due to radio waves having a predetermined frequency radiated from the reader / writer 11, and electromotive force is generated.

  The demodulation unit 102 demodulates the request signal supplied from the antenna 101 by a demodulation method corresponding to the modulation method of the modulation unit 34 (FIG. 2), and supplies the demodulated request signal to the SPU 103. For example, the demodulator 102 envelope-detects and demodulates a request signal that is an ASK modulated wave received via the antenna 101, and outputs the demodulated request signal to the SPU 103.

  The SPU 103 decodes the request signal supplied from the demodulation unit 102 by a predetermined method, and supplies the decoded request signal to the control unit 104. The SPU 103 encodes the response signal supplied from the control unit 104 by a predetermined encoding method, and supplies the encoded response signal to the modulation unit 109. For example, when the data demodulated by the demodulator 102 is encoded by the Manchester method, the SPU 103 decodes the data (Manchester) based on a clock signal supplied from a PLL (Phase Locked Loop) circuit (not shown). Code decoding), and supplies the decoded data to the control unit 104. For example, the SPU 103 encodes the response signal supplied from the control unit 104 using the Manchester method, and supplies the encoded response signal to the modulation unit 109.

  The control unit 104 is configured by, for example, a CPU (Central Processing Unit) and the like, and realizes its function by executing a program stored in the RAM 107. An encryption key update request signal (see FIG. 6C) including an encryption key encrypted by the reader / writer 11 using the same key as the reading common key recorded in the nonvolatile memory 106 is transmitted from the reader / writer 11 to the antenna 101. And supplied from the SPU 103. When the encryption key update request signal is supplied, the control unit 104 decrypts and decrypts the encrypted encryption key included in the encryption key update request signal with the read common key recorded in the nonvolatile memory 106. The encryption key obtained in this way is recorded in the RAM 107. Here, the encryption key obtained by decryption is recorded in the RAM 107, but may be recorded in the nonvolatile memory 106.

  When the write request signal is supplied, the control unit 104 may determine the encryption key update request flag included in the write request signal. When it is determined that the value for requesting encryption key update is set in the encryption key update request flag, the write request signal is recognized as the encryption key update request signal. As a result, the existing write request signal can be used as the encryption key update request signal, and there is an advantage that development efficiency is improved.

  The control unit 104 receives a read request signal including a read target address that designates a data read source area in the nonvolatile memory 106, which is encrypted by the reader / writer 11 with the same encryption key. Is received from the antenna 101 and supplied from the SPU 103. When the read request signal is supplied, the control unit 104 decrypts the encrypted read target address included in the read request signal with the encryption key recorded in the RAM 107, and decrypts the area of the nonvolatile memory 106. The data recorded in the area specified by the read target address obtained in this way is supplied to the SPU 103. This data is transmitted to the reader / writer 11 via the antenna 101.

  The control unit 104 receives an encryption key generation request signal (see FIG. 8C) indicating that an encryption key generation is requested from the reader / writer 11 via the antenna 101 and is supplied from the SPU 103. When the encryption key generation request signal is supplied, the control unit 104 generates an encryption key according to a predetermined procedure, and encrypts the generated encryption key with the writing common key recorded in the nonvolatile memory 106. The control unit 104 supplies an encryption key generation response signal (see FIG. 8D) including the encrypted encryption key to the SPU 103. This signal is transmitted to the reader / writer 11 via the antenna 101.

  When the read request signal is supplied, the control unit 104 may determine an encryption key generation request flag included in the read request signal. When it is determined that the value for requesting encryption key update is set in the encryption key generation request flag, the read request signal is recognized as the encryption key generation request signal. As a result, the existing read request signal can be used as the encryption key generation request signal, and there is an advantage that development efficiency is improved.

  The control unit 104 receives a write request signal including write target data encrypted by the reader / writer 11 and a write target address that specifies a write destination area of the write target data in the encrypted nonvolatile memory 106 (FIG. 8 ( a) is received via the antenna 101 and supplied from the SPU 103. When the write request signal is supplied, the control unit 104 decrypts the encrypted write target data and the encrypted write target address with the encryption key recorded in the RAM 107. Although the encryption key is recorded in the RAM 107 here, it may be recorded in the nonvolatile memory 106. The control unit 104 records the write target data obtained by decoding in the area specified by the write target address obtained by decoding, among the areas of the nonvolatile memory 106.

  The recording unit 105 includes a nonvolatile memory 106, a RAM 107, and the like. The nonvolatile memory 106 is configured by, for example, a nonvolatile memory such as flash memory, EEPROM, MRAM, or FeRAM. The non-volatile memory 106 stores various data such as data to be concealed transmitted to the reader / writer 11 and data necessary for executing the program. The nonvolatile memory 106 records at least one of a reading common key and a writing common key as a key used in common with the reader / writer 11.

  The RAM 107 appropriately stores data necessary for program execution. The RAM 107 supplies the stored data to the control unit 104.

  The oscillation circuit 108 generates a clock signal having the same frequency as the request signal received by the antenna 101, and supplies the generated clock signal to the modulation unit 109. For example, the oscillation circuit 108 includes a PLL circuit and generates a clock signal having the same frequency as the clock frequency of the request signal.

  The modulation unit 109 generates a carrier wave based on a clock signal having a predetermined frequency supplied from the oscillation circuit 108. The modulation unit 109 generates a response signal by modulating the response signal supplied from the SPU 103 based on a carrier wave by a predetermined method, and supplies the modulated response signal to the antenna 101. For example, the modulation unit 109 further performs ASK modulation on the response signal encoded by the Manchester method supplied from the SPU 103, and transmits the modulated response signal to the reader / writer 11 via the antenna 101.

  Further, for example, the modulation unit 109 turns on and off a predetermined switching element (not shown) with respect to the response signal supplied from the SPU 103, and applies a predetermined load to the antenna only when the switching element is on. The load on the antenna 101 is varied by connecting the antenna 101 in parallel. The ASK-modulated response signal is transmitted to the reader / writer 11 through the antenna 101 due to a change in the load of the antenna 101 (the terminal voltage of the antenna 36 of the reader / writer 11 is changed).

  The power generation unit 110 generates DC power based on the AC electromotive force generated in the antenna 101 and supplies the generated DC power to each unit of the communication device 12.

  An object of the present invention is to simplify the authentication process of such a system according to the application, and to speed up the processing while maintaining the encryption strength. That is, the use is roughly classified into two types: a read request with encryption and a write request with encryption using an encryption key generated using a certain common key.

  When a read request with encryption (Read_Req) is performed, a random number generated by the reader / writer 11 is used as an encryption key. Prior to transmitting Read_Req, the reader / writer 11 transmits Write_SK_Req for requesting the update of the encryption key to the communication device 12 as an authentication process.

  FIG. 6 is a block diagram showing a data configuration used when the communication system according to the embodiment of the present invention reads data. With reference to FIG. 6, the structure of data used when the communication system according to the embodiment of the present invention reads data will be described.

  As shown in FIG. 6A, the read request (Read_Req) includes a request identifier for identifying the request, a session ID (SID) for identifying the session, and a data read source area in the nonvolatile memory 106 (see FIG. 5). The read target address (ADDR) to be specified is included. As shown in FIG. 6A, the session ID (SID) and the read target data (DATA) are the encryption targets.

  As shown in FIG. 6B, the read response (Read_Res) includes a response identifier for identifying the response, a session ID (SID) for identifying the session, a result code (SF) indicating the processing result for the request, and the nonvolatile memory 106. Data to be read (DATA) read from (see FIG. 5) is included. Further, as shown in FIG. 6B, the session ID (SID), the result code (SF), and the read target data (DATA) are to be encrypted.

  As shown in FIG. 6C, the encryption key update request (Write_SK_Req) includes a request identifier that identifies the request, a device identifier (IDm) that identifies the communication device 12 (see FIG. 2), and a common key that identifies the common key. An identifier (PKID) and an encryption key (SK) are included. Further, as shown in FIG. 6C, the encryption key (SK) is the encryption target.

  As shown in FIG. 6D, the encryption key update response (Write_SK_Res) includes a response identifier for identifying the response, a device identifier (IDm) for identifying the communication device 12 (see FIG. 2), and a result indicating the processing result for the request. The code (SF) is included.

  FIG. 7 is a sequence diagram showing a flow of processing at the time of data reading by the communication system according to the embodiment of the present invention. With reference to FIG. 7, the process at the time of data reading by the communication system according to the embodiment of the present invention will be described.

  The reader / writer 11 generates an encryption key (SK) in step S111. That is, the reader / writer 11 generates a random number and holds it as an encryption key (SK). Next, using a common key (PK) as an authentication key, this is encrypted by a predetermined procedure to obtain encrypted data Enc (PK, SK). Enc (PK, SK) is transmitted to the communication device 12 as a parameter of Write_SK_Req.

  In step S221, the communication device 12 that has received the Write_SK_Req decrypts the Enc (PK, SK) parameter of the Write_SK_Req using a common key (PK) corresponding to the common key identifier (PKID), and performs encryption. Obtain a key (SK). Thereby, the encryption key (SK) can be shared between the reader / writer 11 and the communication device 12. As one embodiment, Write_SK_Res includes a success / failure determination code (SF) as a parameter and returns it. The subsequent encryption communication process is the same as the example shown in FIG.

  By the processing at the time of data reading described above, it is possible to realize high-speed encryption communication that shares a session key (encryption key) in a system that only performs secure reading from the security device (communication device 12).

Specifically, since data can be read out by performing communication between the reader / writer 11 and the communication device 12 for two reciprocations, encrypted communication can be realized at high speed. Further, since it is not necessary for the communication device 12 to perform a process for generating a random number (a process for generating a key), it is possible to realize encrypted communication at high speed. In addition, since data transmitted and received between the reader / writer 11 and the communication device 12 is encrypted, safety can be maintained.

  FIG. 8 is a block diagram showing a configuration of data used when the communication system according to the embodiment of the present invention writes data. With reference to FIG. 8, the structure of data used when the communication system according to the embodiment of the present invention writes data will be described.

  As shown in FIG. 8A, the write request (Write_Req) includes a request identifier for identifying the request, a session ID (SID) for identifying the session, and a data write destination area in the nonvolatile memory 106 (see FIG. 5). It includes a write target address (ADDR) and write target data (DATA) to be designated. As shown in FIG. 8A, the session ID (SID), the write target address (ADDR), and the write target data (DATA) to be written to the nonvolatile memory 106 (see FIG. 5) are the encryption targets.

  As shown in FIG. 8B, the write response (Write_Res) includes a response identifier that identifies the response, a session ID (SID) that identifies the session, and a result code (SF) that indicates the processing result for the request. As shown in FIG. 8B, the session ID (SID) and the result code (SF) are to be encrypted.

  As shown in FIG. 8C, the encryption key generation request (Read_SK_Req) includes a request identifier for identifying the request, a device identifier (IDm) for identifying the communication device 12 (see FIG. 2), and a common key for identifying the common key. An identifier (PKID) is included.

  As shown in FIG. 8D, the encryption key generation response (Read_SK_Res) includes a response identifier for identifying the response, a device identifier (IDm) for identifying the communication device 12 (see FIG. 2), and a result indicating the processing result for the request. A code (SF) and an encryption key (SK) are included. As shown in FIG. 8D, the encryption key (SK) is to be encrypted.

  FIG. 9 is a sequence diagram showing a flow of processing at the time of data writing by the communication system according to the embodiment of the present invention. With reference to FIG. 9, the process at the time of data writing by the communication system according to the embodiment of the present invention will be described.

The reader / writer 11 first transmits Read_SK_Req to the communication device 12. At this time, a common key (PK) identifier (PKID) is simultaneously transmitted as a parameter.
The communication apparatus 12 that has received Read_SK_Req generates an encryption key (SK) in step S231. That is, the communication device 12 generates a random number and holds it as an encryption key (SK). Next, the encryption key (SK) is encrypted by a predetermined procedure using the common key (PK) corresponding to the common key identifier (PKID) to obtain encrypted data Enc (PK, SK). Enc (PK, SK) is returned to the reader / writer 11 as a parameter of Read_SK_Res.

  In step S131, the reader / writer 11 that has received Read_SK_Res decrypts Enc (PK, SK) of the parameter of Read_SK_Res using a common key (PK) and obtains an encryption key (SK). Thereby, the encryption key (SK) can be shared between the reader / writer 11 and the communication device 12. The subsequent encryption communication process is the same as the example in FIG.

  Through the above-described processing at the time of data writing, it is possible to realize high-speed encrypted communication in which a session key (encryption key) is shared in a system that performs only secure writing to the security device (communication device 12). Specifically, since data can be written by performing communication between the reader / writer 11 and the communication device 12 for two reciprocations, encrypted communication can be realized at high speed. In addition, since it is not necessary for the reader / writer 11 to perform a process of generating a random number (a process of generating a key), it is possible to realize encrypted communication at high speed. In addition, since data transmitted and received between the reader / writer 11 and the communication device 12 is encrypted, safety can be maintained.

  The communication system 10 may perform both the data reading process and the data writing process described above. In that case, authentication or encrypted communication using different key values in the read process and the write process can be realized for the data area of the security device (communication device 12). In this case, since the key value used at the time of data reading and the key value used at the time of data writing are different, security against attacks against both data reading and data writing is improved.

  The present invention can be applied to an information processing system that transmits and receives data via a wired or wireless communication network, an electronic money system using an IC card, a security system, and the like.

  In the above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

DESCRIPTION OF SYMBOLS 10 Communication system 11 Reader / writer 12 Communication apparatus 31 Control part 32 Recording part 33 SPU
34 Modulation unit 35 Oscillation circuit 36 Antenna (communication unit)
37 demodulator 38 drive 71 magnetic disk 72 optical disk 73 magneto-optical disk 74 semiconductor memory 101 antenna 102 demodulator 103 SPU
104 Control unit 105 Recording unit 106 Non-volatile memory 107 RAM
108 Oscillator 109 109 Modulator 110 Power Generator 112 Recording Unit

Claims (4)

  A communication unit that transmits and receives signals to and from a reader / writer;
  A control unit;
  A session key generation information generation unit,
  The control unit uses a common key shared with the reader / writer to share a session key generated based on a random number generated by the reader / writer with the reader / writer,
  When data including information designating a reading target is received from the reader / writer by a Read command, encrypted data encrypted based on the session key and the reading target data is generated, and the data is transmitted via the communication unit. Send it to the reader / writer,
  The control unit further uses the common key shared with the reader / writer to generate a session key generated based on the information generated by the session key generation information generation unit with the reader / writer. Share,
  From the reader / writer, when the encrypted data that includes the information specifying the write target and is encrypted based on the session key and the write target data is received by the Write command, the write target data is written.
  Communication device. The information generated by the session key generation information generation unit is a random number.
  The communication apparatus according to claim 1.   The control unit in the communication device includes a communication unit that transmits and receives signals to and from the reader / writer, a control unit, and a session key generation information generation unit.
  Using a common key shared with the reader / writer, a session key generated based on a random number generated by the reader / writer is shared with the reader / writer,
  When data including information designating a reading target is received from the reader / writer by a Read command, encrypted data encrypted based on the session key and the reading target data is generated, and the data is transmitted via the communication unit. Send it to the reader / writer,
  Using a common key shared with the reader / writer, a session key generated based on the information generated by the session key generation information generating unit is shared with the reader / writer,
  From the reader / writer, when the encrypted data that includes the information specifying the write target and is encrypted based on the session key and the write target data is received by the Write command, the write target data is written.
  Communication method. The information generated by the session key generation information generation unit is a random number.
  The communication method according to claim 3.

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