Patent Publication Number: US-2012045055-A1

Title: Communication device, information processing system, and encryption switching method

Description:
BACKGROUND 
     The present disclosure relates to a communication device, an information processing system, and an encryption switching method. 
     In the related art, an integrated circuit (IC) card in which an IC capable of recording or calculating information is embedded has been put into practical use. Above all, the IC card, which is also referred to as a smart card, includes a processor within the IC and implements advanced information processing, has recently been widely used in various use applications as a payment means or an individual identification means in everyday life. 
     The technology development for more advanced security when various services are used with the IC card has also continued in accordance with the extension of use scenes of the IC card. For example, in terms of an encryption type for encrypting data, an advanced encryption standard (AES) type capable of selecting three kinds of key lengths of 128 bits, 192 bits, and 256 bits has started to be adopted by various authorities, in place of a data encryption standard (DES) type as a 64-bit block encryption type widely used in the past. 
     This applicant has proposed technology capable of removing an additional procedure when an encryption type corresponding to an IC card is switched (for example, see Japanese Patent Application Laid-Open No. 2010-98367). 
     SUMMARY 
     Incidentally, it is necessary to perform switching to an encryption type having a higher security strength for a reader/writer (R/W), which communicates with an IC card, in accordance with switching to a type having a higher security strength than an encryption type for an IC card. 
     For example, an R/W system, which is an information processing system mounted at a ticket gate of a station or the like, includes an R/W control device and an R/W. The R/W control device controls the R/W. The R/W is a secure device having an antenna module. The R/W control device and the R/W are communicable with each other after performing mutual authentication. 
     In the above-described R/W system, it is not preferable to switch the encryption type of the R/W control device and switch the encryption type of the R/W by temporarily stopping the entire system due to a high risk. In a transition period of switching the encryption type, it is necessary for the R/W control device or the R/W to have a communication function and an authentication function in an old encryption type and a communication function or an authentication function in a new encryption type. 
     For example, after the R/W is first replaced by one corresponding to both the old encryption type and the new encryption type in switching of the encryption type of the R/W system, the R/W control device is replaced by one corresponding to both the old encryption type and the new encryption type. After the R/W control device and the R/W perform the mutual authentication in the old encryption type, the R/W control device switches the encryption type of the R/W from the old encryption type to the new encryption type, and the R/W control device switches its own encryption type from the old encryption type to the new encryption type. 
     However, because the R/W control device only performs the mutual authentication based on the old encryption type with the R/W in switching of the encryption type of the above-described R/W system, it is necessary for the R/W control device to be replaced by one corresponding to both the old encryption type and the new encryption type. Thus, a developer of the R/W control device has a burden to make the R/W control device corresponding to both the old encryption type and the new encryption type. 
     It is desirable to provide a novel and improved communication device, information processing system, and encryption switching method that can reduce the burden when an encryption type is switched. 
     According to an embodiment of the present disclosure, there is provided a communication device including a change request reception unit for receiving a change request for temporarily changing an encryption type of the communication device transmitted from an information processing device, an encryption type change unit for temporarily changing the encryption type of the communication device on the basis of the change request received by the change request reception unit, and an authentication information transmission unit for transmitting authentication information for causing the information processing device to authenticate the communication device encrypted in the encryption type temporarily changed by the encryption type change unit to the information processing device. 
     The communication device may further include an authentication information reception unit for receiving authentication information for causing the communication device to authenticate the information processing device encrypted in the encryption type temporarily changed by the encryption type change unit transmitted from the information processing device, and an authentication unit for authenticating the information processing device on the basis of the authentication information received by the authentication information reception unit. 
     The communication device may further include a setting request reception unit for receiving a setting request for setting the encryption type of the communication device to the encryption type temporarily changed by the encryption type change unit transmitted from the information processing device, and an encryption type setting unit for setting the encryption type of the communication device to the encryption type temporarily changed by the encryption type change unit on the basis of the setting request received by the setting request reception unit. 
     If the change request is a change request for temporarily changing the encryption type of the communication device from a first encryption type to a second encryption type having a higher security strength than the first encryption type, the encryption type change unit may temporarily change the encryption type of the communication device from the first encryption type to the second encryption type. 
     According to an embodiment of the present disclosure, there is provided an information processing system including an information processing device, and a communication device. The information processing device includes a change request transmission unit for transmitting a change request for temporarily changing an encryption type of the communication device to the communication device, an authentication information reception unit for receiving authentication information for causing the information processing device to authenticate the communication device encrypted in the encryption type temporarily changed by the change request transmitted from the communication device, and an authentication unit for authenticating the communication device on the basis of the authentication information received by the authentication information reception unit. The communication device includes a change request reception unit for receiving the change request transmitted from the information processing device, an encryption type change unit for temporarily changing the encryption type of the communication device on the basis of the change request received by the change request reception unit, and an authentication information transmission unit for transmitting the authentication information for causing the information processing device to authenticate the communication device encrypted in the encryption type temporarily changed by the encryption type change unit to the information processing device. 
     The information processing device may further include an authentication information transmission unit for transmitting the authentication information for causing the communication device to authenticate the information processing device encrypted in the encryption type temporarily changed by the encryption type change unit of the communication device to the communication device. The communication device may further include an authentication information reception unit for receiving the authentication information for causing the communication device to authenticate the information processing device encrypted in the encryption type temporarily changed by the encryption type change unit transmitted from the information processing device, and an authentication unit for authenticating the information processing device on the basis of the authentication information received by the authentication information reception unit. 
     According to an embodiment of the present disclosure, there is provided an encryption switching method including receiving a change request for temporarily changing an encryption type of a communication device transmitted from an information processing device, temporarily changing the encryption type of the communication device on the basis of the received change request, and transmitting authentication information for causing the information processing device to authenticate the communication device encrypted in the temporarily changed encryption type to the information processing device. 
     The encryption switching method may further include receiving the authentication information for causing the communication device to authenticate the information processing device encrypted in the temporarily changed encryption type transmitted from the information processing device, and authenticating the information processing device on the basis of the received authentication information. 
     According to the embodiments of the present disclosure described above, it is possible to reduce the burden when an encryption type is switched. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustrative diagram schematically showing a configuration of an information processing system according to a first embodiment of the present disclosure; 
         FIG. 2  is a block diagram schematically showing functional configurations of an R/W control device and an R/W of  FIG. 1 ; 
         FIG. 3  is a sequence diagram of encryption switching processing to be executed by the R/W control device and the R/W of  FIG. 1 ; 
         FIG. 4A  is an illustrative diagram illustrating switching of an encryption type of an R/W system; 
         FIG. 4B  is an illustrative diagram illustrating switching of an encryption type of an R/W system; 
         FIG. 4C  is an illustrative diagram illustrating switching of an encryption type of an R/W system; 
         FIG. 5  is an illustrative diagram schematically showing a configuration of an information processing system according to a second embodiment of the present disclosure; 
         FIG. 6  is a block diagram schematically showing functional configurations of a camera device and a battery of  FIG. 5 ; 
         FIG. 7  is a sequence diagram of encryption switching processing to be executed by the camera device and the battery of  FIG. 5 ; 
         FIG. 8A  is an illustrative diagram illustrating switching of an encryption type of a camera system; 
         FIG. 8B  is an illustrative diagram illustrating switching of an encryption type of a camera system; and 
         FIG. 8C  is an illustrative diagram illustrating switching of an encryption type of a camera system. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. 
     Description will be given in the following order. 
     1. Configuration of Information Processing System (First Embodiment) 
     2. Functional Configurations of R/W Control Device and R/W 
     3. Encryption Switching Processing (First Embodiment) 
     4. Configuration of Information Processing System (Second Embodiment) 
     5. Functional Configurations of Camera Device and Battery 
     6. Encryption Switching Processing (Second Embodiment) 
     [1. Configuration of Information Processing System (First Embodiment)] 
     First, the information processing system according to the first embodiment of the present disclosure will be described.  FIG. 1  is an illustrative diagram schematically showing the configuration of the information processing system according to this embodiment. Hereinafter, an example in which the information processing system is an R/W system mounted at a ticket gate of a station or the like will be described. 
     In  FIG. 1 , an R/W system  100 , which is the information processing system, includes an R/W control device  200  and an R/W  300 . The R/W control device  200  is an example of the information processing device of the present disclosure, and controls the R/W  300 . The R/W  300  is an example of a communication device of the present disclosure, and is a secure device including an antenna module. For example, the R/W  300  is communicable with a non-contact IC card  400  in a non-contact type. The R/W  300  may be communicable with a contact IC card (not shown) in a contact type. Also, the R/W control device  200  and the R/W  300  are communicable with each other after performing mutual authentication. 
     [2. Functional Configurations of R/W Control Device and R/W] 
     Next, the functional configurations of the R/W control device  200  and the R/W  300  of  FIG. 1  will be described.  FIG. 2  is a block diagram schematically showing the functional configurations of the R/W control device  200  and the R/W  300  of  FIG. 1 . 
     In  FIG. 2 , the R/W control device  200  includes a communication unit  202 , a control unit  204 , and a storage unit  206 . The control unit  204  includes a transmission unit  208 , a reception unit  210 , and an authentication unit  212 . 
     The communication unit  202  is communicable with a communication unit  302  of the R/W  300 , and exchanges information. The control unit  204  controls the entire R/W control device  200 . The storage unit  206  stores an encryption key of the encryption type of the R/W control device  200 , or the like. 
     The transmission unit  208  of the control unit  204  transmits a change request for temporarily changing the encryption type of the R/W  300  to the R/W  300  via the communication unit  202 . Also, the transmission unit  208  encrypts authentication information for causing the R/W  300  to authenticate the R/W control device  200  in the encryption type temporarily changed in the R/W  300 , and transmits the encrypted authentication information to the R/W  300  via the communication unit  202 . The transmission unit  208  transmits a setting request for setting the encryption type of the R/W  300  to the temporarily changed encryption type to the R/W  300  via the communication unit  202 . 
     The reception unit  210  of the control unit  204  receives a response to the change request transmitted by the transmission unit  208  from the R/W  300  via the communication unit  202 . Also, the reception unit  210  receives authentication information for causing the R/W control device  200  to authenticate the R/W  300  encrypted in the encryption type temporarily changed in the R/W  300  from the R/W  300  via the communication unit  202 . Also, the reception unit  210  receives a response to the setting request transmitted by the transmission unit  208  from the R/W  300  via the communication unit  202 . 
     The authentication unit  212  of the control unit  204  authenticates the R/W  300  on the basis of the authentication information received by the reception unit  210  of the R/W control device  200 . 
     On the other hand, the R/W  300  includes the communication unit  302 , a wireless communication unit  304 , a control unit  306 , and a storage unit  308 . The control unit  306  includes a transmission unit  310 , a reception unit  312 , an authentication unit  314 , an encryption type change unit  316 , and an encryption type setting unit  318 . 
     The communication unit  302  is communicable with the communication unit  202  of the R/W control device  200 , and exchanges information. Also, the communication unit  302  may be communicable with a contact IC card (not shown). The wireless communication unit  304  is communicable with the non-contact IC card  400  in a non-contact type, and exchanges information. The control unit  306  controls the entire R/W  300 . The storage unit  308  stores an encryption key of the encryption type of the R/W  300 , or the like. 
     The transmission unit  310  of the control unit  306  is an example of an authentication information transmission unit of the present disclosure, and transmits the response to the change request transmitted by the transmission unit  208  of the R/W control device  200  to the R/W control device  200  via the communication unit  302 . Also, the transmission unit  310  encrypts the authentication information for causing the R/W control device  200  to authenticate the R/W  300  in the encryption type temporarily changed in the R/W  300 , and transmits the encrypted authentication information to the R/W control device  200  via the communication unit  302 . Also, the transmission unit  310  transmits the response to the setting request transmitted by the transmission unit  208  of the R/W control device  200  to the R/W control device  200  via the communication unit  302 . 
     The reception unit  312  of the control unit  306  is an example of a change request reception unit, an authentication information reception unit, and a setting request reception unit of the present disclosure, and receives the change request for temporarily changing the encryption type of the R/W  300  transmitted by the transmission unit  208  of the R/W control device  200  via the communication unit  302 . Also, the reception unit  312  receives the authentication information for causing the R/W  300  to authenticate the R/W control device  200  encrypted in the encryption type temporarily changed in the R/W  300  from the R/W control device  200  via the communication unit  302 . Also, the reception unit  312  receives the setting request for setting the encryption type of the R/W  300  to the temporarily changed encryption type from the R/W control device  200  via the communication section  302 . 
     The authentication unit  314  of the control unit  306  authenticates the R/W control device  200  on the basis of the authentication information received by the reception unit  312  of the R/W  300 . 
     The encryption type change unit  316  of the control unit  306  temporarily changes the encryption type of the R/W  300  on the basis of a change request received by the reception unit  312  of the R/W  300 . 
     The encryption type setting unit  318  of the control unit  306  sets the encryption type of the R/W  300  to the encryption type temporarily changed by the encryption type change unit  316  on the basis of the setting request received by the reception unit  312  of the R/W  300 . 
     [3. Encryption Switching Processing (First Embodiment)] 
     Next, the encryption switching processing to be executed by the R/W control device  200  and the R/W  300  of  FIG. 1  will be described.  FIG. 3  is a sequence diagram of the encryption switching processing to be executed by the R/W control device  200  and the R/W  300  of  FIG. 1 . 
     In  FIG. 3 , first, the transmission unit  208  of the R/W control device  200  transmits a change request for temporarily changing the encryption type of the R/W  300  from an old encryption type, for example, a DES type, to a new encryption type, for example, an AES type, to the R/W  300  via the communication unit  202  (step S 102 ). For example, in step S 102 , the transmission unit  208  of the R/W control device  200  transmits the change request to the R/W  300  without encrypting the change request. The DES type is an example of a first encryption type of the present disclosure, and the AES type is an example of a second encryption type of the present disclosure. 
     Then, the reception unit  312  of the R/W  300  receives the change request for temporarily changing the encryption type of the R/W  300  transmitted in step S 102  from the old encryption type to the new encryption type via the communication unit  302 , and the encryption type change unit  316  of the R/W  300  temporarily changes the encryption type of the R/W  300  from the old encryption type to the new encryption type on the basis of the change request received by the reception unit  312  of the R/W  300  (step S 104 ). 
     Then, the transmission unit  310  of the R/W  300  transmits a response to the change request transmitted in step S 102  to the R/W control device  200  via the communication unit  302  (step S 106 ). 
     Then, after the reception unit  210  of the R/W control device  200  receives the response transmitted in step S 106 , the transmission unit  208  of the R/W control device  200  encrypts the authentication information for causing the R/W  300  to authenticate the R/W control device  200  in the new encryption type temporarily changed in step S 104 , and transmits the encrypted authentication information to the R/W  300  via the communication unit  202  (step S 108 ). 
     Then, the reception unit  312  of the R/W  300  receives the authentication information transmitted in step S 108 , and the transmission unit  310  of the R/W  300  encrypts the authentication information for causing the R/W control device  200  to authenticate the R/W  300  in the new encryption type temporarily changed in step S 104 , and transmits the encrypted authentication information to the R/W control device  200  via the communication unit  302  (step S 110 ). 
     Then, the reception unit  210  of the R/W control device  200  receives the authentication information transmitted in step S 110 , and the authentication unit  212  of the R/W control device  200  authenticates the R/W  300  on the basis of the authentication information received by the reception unit  210  of the R/W control device  200  (step S 112 ). 
     Then, the transmission unit  208  of the R/W control device  200  encrypts the authentication information for causing the R/W  300  to authenticate the R/W control device  200  in the new encryption type temporarily changed in step S 104 , and transmits the encrypted authentication information to the R/W  300  via the communication unit  202  (step S 114 ). 
     Then, the reception unit  312  of the R/W  300  receives the authentication information transmitted in step S 114 , and the authentication unit  314  of the R/W  300  authenticates the R/W control device  200  on the basis of the authentication information received by the reception unit  312  of the R/W  300  (step S 116 ). 
     Then, the transmission unit  310  of the R/W  300  transmits a response indicating that the authentication of the R/W control device  200  has been completed to the R/W control device  200  via the communication unit  302  (step S 118 ). 
     Then, the transmission unit  208  of the R/W control device  200  transmits a setting request for setting the encryption type of the R/W  300  to the new encryption type temporarily changed in step S 104  to the R/W  300  via the communication unit  202  (step S 120 ). 
     Then, the reception unit  312  of the R/W  300  receives the setting request transmitted in step S 120 , and the encryption type setting unit  318  of the R/W  300  sets the encryption type of the R/W  300  to the new encryption type temporarily changed in step S 104  on the basis of the setting request received by the reception unit  312  of the R/W  300  (step S 122 ). For example, in step S 122 , the encryption type setting unit  318  of the R/W  300  sets a parameter of the encryption type stored in the storage unit  308  of the R/W  300  from a parameter of the old encryption type to a parameter of the new encryption type. Thereby, it is possible to permanently set the encryption type of the R/W  300  to the new encryption type. 
     Then, the transmission unit  310  of the R/W  300  transmits a response to the setting request transmitted in step S 120  to the R/W control device  200  via the communication unit  302  (step S 124 ), and the reception unit  210  of the R/W control device  200  terminates this processing after receiving the response transmitted in step S 124 . 
     According to the encryption switching processing of  FIG. 3 , the R/W control device  200  sets the encryption type of the R/W  300  from the old encryption type to the new encryption type after mutual authentication is performed on the basis of the authentication information encrypted in the new encryption type by temporarily changing the encryption type of the R/W  300  from the old encryption type to the new encryption type. Thereby, because it is not necessary for the R/W control device  200  and the R/W  300  to perform the mutual authentication in the old encryption type, it is not necessary to set the R/W control device  200  to one corresponding to both the old encryption type and the new encryption type, and it is possible to reduce the burden of a developer of the R/W control device  200 . 
     For example, in switching of the encryption type of the R/W system including an old correspondence R/W control device corresponding to the old encryption type and an old correspondence R/W corresponding to the old encryption type as shown in  FIG. 4A , the R/W is first replaced by an old and new correspondence R/W corresponding to the new encryption type and the old encryption type as shown in  FIG. 4B . As shown in  FIG. 4C , the R/W control device is replaced by the new correspondence R/W control device corresponding to the new encryption type. In an R/W system including the new correspondence R/W control device corresponding to the new encryption type and the old and new correspondence R/W corresponding to the new encryption type and the old encryption type shown in  FIG. 4C , the switching of the encryption type of the R/W system is completed by executing the encryption switching processing of  FIG. 3  described above and switching the encryption type of the R/W from the old encryption type to the new encryption type. Thereby, in switching of the encryption type of the R/W system, it is not necessary to replace the R/W control device with the old and new correspondence R/W control device corresponding to the new encryption type and the old encryption type, and it is possible to reduce the burden of the developer of the R/W control device. 
     In this embodiment, if the change request received by the reception unit  312  of the R/W  300  is a change request for temporarily changing the encryption type of the R/W  300  from a current encryption type to another encryption type having a higher security strength than the current encryption type, the encryption type change unit  316  of the R/W  300  temporarily changes the encryption type of the R/W  300  from the current encryption type to the other encryption type. Thereby, it is possible to prevent the R/W  300  from being changed to another encryption type having a lower security strength than the current encryption type. 
     In this embodiment, the transmission unit  208  of the R/W control device  200  can transmit a setting request for returning the encryption type of the R/W  300  from the new encryption type set in step S 118  to the original old encryption type to the R/W  300  via the communication unit  202 . 
     [4. Configuration of Information Processing System (Second Embodiment)] 
     Next, the information processing system according to the second embodiment of the present disclosure will be described.  FIG. 5  is an illustrative diagram schematically showing the configuration of the information processing system according to this embodiment. Hereinafter, an example in which the information processing system is a camera system constituted by a camera device and a battery will be described. 
     In  FIG. 5 , a camera system  500 , which is the information processing system, includes a camera device  600  and a battery  700 . The camera device  600  is an example of the information processing device of the present disclosure. The battery  700  is an example of the communication device of the present disclosure. The camera device  600  can acquire power from the battery  700  after the authentication of the battery  700  is performed. 
     [4. Functional Configurations of Camera Device and Battery] 
     Next, the functional configurations of the camera device  600  and the battery  700  of  FIG. 5  will be described.  FIG. 6  is a block diagram schematically showing the functional configurations of the camera device  600  and the battery  700  of  FIG. 5 . 
     In  FIG. 6 , the camera device  600  includes a communication unit  602 , a control unit  604 , and a storage unit  606 . The control unit  604  includes a transmission unit  608 , a reception unit  610 , and an authentication unit  612 . The camera device  600  has various functional configurations to function as a camera, but description thereof is omitted because they are not directly related to the present disclosure. 
     The communication unit  602  is communicable with a communication unit  702  of the battery  700 , and exchanges information. The control unit  604  controls the entire camera device  600 . The storage unit  606  stores an encryption key of an encryption type of the camera device  600 , or the like. 
     The transmission unit  608  of the control unit  604  transmits a change request for temporarily changing the encryption type of the battery  700  to the battery  700  via the communication unit  602 . 
     The reception unit  610  of the control unit  604  receives a response to the change request transmitted by the transmission unit  608  from the battery  700  via the communication unit  602 . Also, the reception unit  610  receives authentication information for causing the camera device  600  to authenticate the battery  700  encrypted in the encryption type temporarily changed in the battery  700  from the battery  700  via the communication unit  602 . 
     The authentication unit  612  of the control unit  604  authenticates the battery  700  on the basis of the authentication information received by the reception unit  610  of the camera device  600 . 
     On the other hand, the battery  700  includes a communication unit  702 , an encryption type change unit  704 , and a storage unit  706 . Also, the battery  700  has various functional configurations to function as a battery, but description thereof is omitted because they are not directly related to the present disclosure. 
     The communication unit  702  is communicable with the communication unit  602  of the camera device  600 , and exchanges information. The encryption type change unit  704  is an example of a change request reception unit and an authentication information transmission unit, and receives the change request for temporarily changing the encryption type of the battery  700  transmitted by the transmission unit  608  of the camera device  600  via the communication unit  702 . Also, the encryption type change unit  704  temporarily changes the encryption type of the R/W  300  on the basis of the change request received by the reception unit  312  of the R/W  300 . Also, the encryption type change unit  704  transmits a response to the change request transmitted by the transmission unit  608  of the camera device  600  to the camera device  600  via the communication unit  702 . Also, the encryption type change unit  704  encrypts the authentication information for causing the camera device  600  to authenticate the battery  700  in the encryption type temporarily changed in the battery  700 , and transmits the encrypted authentication information to the camera device  600  via the communication unit  702 . The storage unit  706  stores an encryption key of the encryption type of the battery  700 , or the like. 
     [6. Encryption Switching Processing (Second Embodiment)] 
     Next, the encryption switching processing to be executed by the camera device  600  and the battery  700  of  FIG. 5  will be described.  FIG. 7  is a sequence diagram of the encryption switching processing to be executed by the camera device  600  and the battery  700  of  FIG. 5 . 
     In  FIG. 7 , first, the transmission unit  608  of the camera device  600  transmits a change request for temporarily changing the encryption type of the battery  700  from an old encryption type, for example, a DES type, to a new encryption type, for example, an AES type, to the battery  700  via the communication unit  602  (step S 202 ). For example, in step S 202 , the transmission unit  608  of the camera device  600  transmits the change request to the battery  700  without encrypting the change request. The DES type is an example of a first encryption type of the present disclosure, and the AES type is an example of a second encryption type of the present disclosure. 
     Then, the encryption type change unit  704  of the battery  700  receives the change request for temporarily changing the encryption type of the battery  700  transmitted in step S 202  from the old encryption type to the new encryption type via the communication unit  702 , and temporarily changes the encryption type of the battery  700  from the old encryption type to the new encryption type on the basis of the received change request (step S 204 ). 
     Then, the encryption type change unit  704  of the battery  700  transmits a response to the change request transmitted in step S 202  to the camera device  600  via the communication unit  702  (step S 206 ). 
     Then, after the response is transmitted in step S 206 , the encryption type change unit  704  of the battery  700  encrypts authentication information for causing the camera device  600  to authenticate the battery  700  in the new encryption type temporarily changed in step S 204 , and transmits the encrypted authentication information to the camera device  600  via the communication unit  702  (step S 208 ). 
     Then, the reception unit  610  of the camera device  600  receives the authentication information transmitted in step S 208 , and the authentication unit  612  of the camera device  600  terminates this processing by authenticating the battery  700  on the basis of the authentication information received by the reception unit  610  of the camera device  600  (step S 210 ). 
     According to the encryption switching processing of  FIG. 7 , one-sided authentication is performed on the basis of the authentication information encrypted in the new encryption type by temporarily changing the encryption type of the battery  700  from the old encryption type to the new encryption type. Thereby, it is not necessary to replace the camera device  600  with one corresponding to the old encryption type and the new encryption type because it is not necessary for the camera device  600  to authenticate the battery  700  in the old encryption type, and it is possible to reduce the burden of a developer of the camera device  600 . 
     For example, in switching of the encryption type of the camera system including an old correspondence camera device corresponding to the old encryption type and an old correspondence battery corresponding to the old encryption type as shown in  FIG. 8A , the battery is first replaced with an old and new correspondence battery corresponding to the new encryption type and the old encryption type as shown in  FIG. 8B . As shown in  FIG. 8C , the camera device is replaced with a new correspondence camera device corresponding to the new encryption type. In a camera system including the new correspondence camera device corresponding to the new encryption type and the old and new correspondence battery corresponding to the new encryption type and the old encryption type shown in  FIG. 8C , the switching of the encryption type of the camera system is completed by executing the encryption switching processing of  FIG. 7  described above and switching the encryption type of the battery from the old encryption type to the new encryption type. Thereby, in switching of the encryption type of the camera system, it is not necessary to replace the camera device with the old and new correspondence camera device corresponding to the new encryption type and the old encryption type, and it is possible to reduce the burden of the developer of the camera device. Furthermore, because the new correspondence camera device authenticates the battery in the new encryption type as shown in  FIG. 8C , the authentication of the old correspondence battery fails in the new correspondence camera device. Thereby, the use of the old correspondence battery can be inhibited in the new correspondence camera device. 
     In this embodiment, if the received change request is a change request for temporarily changing the encryption type of the battery  700  from a current encryption type to another encryption type having a higher security strength than the current encryption type, the encryption type change unit  704  of the battery  700  temporarily changes the encryption type of the battery  700  from the current encryption type to the other encryption type. Thereby, it is possible to prevent the battery  700  from being changed to another encryption type having a lower security strength than the current encryption type. 
     An object of the present disclosure is attained by supplying a storage medium storing the program codes of the software for performing the functions of the above-described embodiments to a system or device, and reading and executing the program codes stored in the storage medium by a computer (or a CPU or MPU) of the system or device. 
     In this case, the program codes themselves read from the storage medium implement the functions of the above-described embodiments, and the program codes and the storage medium storing the program codes constitute the present disclosure. 
     As the storage medium for supplying the program codes, for example, a floppy (registered trademark) disk, a hard disk, a magneto-optical disc, an optical disc such as a CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, or DVD+RW, a magnetic tape, a nonvolatile memory card, a ROM, and the like may be used. Alternatively, the program codes may be downloaded via a network. 
     The functions of the above-described embodiments may be implemented not only by executing the program code read by the computer, but also by part or all of actual processing executed by an operating system (OS) or the like running on the computer on the basis of an instruction of the program code. 
     Furthermore, after the program code read from the storage medium is written to a memory provided in a function extension board inserted into the computer or a function extension unit connected to the computer, its extension function may be executed by part or all of actual processing by a CPU or the like provided in the extension board or the extension unit on the basis of an instruction of the program code, and the functions of the above-described embodiments may be implemented by the processing. 
     The preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, but the present disclosure is not limited thereto. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof. 
     An example in which the present disclosure is applied to an R/W system or a camera system has been described above, but the present disclosure is applicable to any system in which it is necessary to switch an encryption type. 
     The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2010-182999 filed in the Japan Patent Office on Aug. 18, 2010, the entire content of which is hereby incorporated by reference.