JP2020191581A - Communication apparatus, communication system, rfid tag and control method for communication apparatus - Google Patents

Abstract

To provide a reader writer capable of achieving secure communication with an RFID tag without complicating management.SOLUTION: A reader writer (2) includes an optical reading section (24) for optically reading an encrypted image showing an encrypted key from an RFID tag (4) which has the encrypted image displayed on a surface of the RFID tag (4), and an RF communication section (23) for transmitting or receiving the data encrypted using an encrypted key to/from the RFID tag (4).SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a reader / writer that performs wireless communication with an RFID tag, a communication device that performs wireless communication by Wifi (registered trademark) or Bluetooth (registered trademark), a communication system, and an RFID tag.

A wireless communication system using a reader / writer and an RFID (Radio Frequency Identifier) tag is known as a prior art. Such a wireless communication system is used, for example, in product management in a factory. Here, when a reader / writer having a long communication distance is used, the RFID tag information may be read even from outside the factory, for example.

Japanese Unexamined Patent Publication No. 2005-0188807

In order to enhance the security of communication, it is conceivable to give an RFID tag an encryption key and perform wireless communication with the information encrypted by the encryption key. However, in this method, if the same encryption key is used for all RFID tags, there is a risk that all the information will be read once the encryption key is decrypted. On the other hand, if the encryption key is changed for each RFID tag, it is necessary to manage it in the host system, which causes a problem that the system itself becomes complicated.

In addition, Patent Document 1 discloses a technique for printing holding information as a number or a bar code on a non-contact card. However, this retained information is used when collating a user using a password, and does not indicate an encryption key.

Further, in Wifi communication, once the encryption key related to the encryption process in the data link layer with the Wifi router is acquired in the communication device, after that, as long as the radio wave reaches from outside the factory, for example, the Wifi router is used. Communication will be possible. Therefore, there is a problem that it is not possible to take measures such as permitting communication only within a predetermined area. A similar problem exists in Bluetooth communication.

One aspect of the present invention is to provide a communication device, a communication system, an RFID tag, and a control method of the communication device that realizes secure communication with the communication device to be communicated without complicating management. To do.

In order to solve the above problems, the communication device according to one aspect of the present invention has an optical reading unit that optically reads an encrypted image showing an encryption key, and the actual data of the payload portion is encrypted by using the encryption key. The configuration includes a first communication unit that wirelessly transmits and receives at least one of the transmitted data frames to the communication device to be communicated.

Further, the control method of the communication device according to one aspect of the present invention includes an optical reading step of optically reading an encrypted image showing an encryption key and a data frame in which the actual data of the payload portion is encrypted using the encryption key. Includes a first communication step of wirelessly transmitting and receiving at least one of the communication devices to be communicated with.

According to the above configuration or method, the communication device can recognize the encryption key of the data wirelessly transmitted and received to and from the communication device to be communicated by optically reading the encrypted image. Therefore, unless the encrypted image can be optically read, the data transmitted and received wirelessly cannot be decrypted, so that more secure communication can be realized by limiting the communication devices capable of communicating.

Further, since the encryption key can be notified to the communication device only by displaying the encrypted image, secure communication can be realized by a simple method without inviting the complexity of the system.

Further, in the communication device according to one aspect of the present invention, the optical reading unit optically reads the encrypted image from the RFID tag on which the encrypted image indicating the encryption key is displayed on the surface of the RFID tag. The first communication unit may be configured to wirelessly transmit or receive data encrypted using the encryption key to the RFID tag.

According to the above configuration, the reader / writer can recognize the encryption key of the data wirelessly transmitted / received to / from the RFID tag by optically reading the encrypted image displayed on the surface of the RFID tag. .. Therefore, unless the encrypted image can be optically read, the data transmitted and received wirelessly cannot be decrypted, so that secure communication with the RFID tag can be realized.

Further, since the encryption key can be notified to the reader / writer only by displaying the encrypted image on the surface of the RFID tag, secure communication can be realized by a simple method without incurring the complexity of the system.

In the above configuration, the communication device according to one aspect of the present invention decrypts the encrypted data received from the first encryption unit that encrypts the data by using the encryption key or the RFID tag. A first decoding unit may be provided.

According to the above configuration, the communication device encrypts or decrypts data using the encryption key acquired from the RFID tag, and transmits or receives data between the RFID tags, thus ensuring security during communication processing. Can be improved.

In the above configuration, the communication device according to one aspect of the present invention has a first mode of receiving the data encrypted from the RFID tag when reading the data from the RFID tag, and encryption from the RFID tag. A mode selection unit for switching between a second mode for receiving unencrypted data and the mode selection unit is provided, and the mode selection unit receives the unencrypted data from the RF communication unit so as to transmit the unencrypted data at least in the second mode. It may be configured to instruct the RFID tag.

According to the above configuration, the data received from the RFID tag by the communication device can be switched between encrypted and unencrypted data, and therefore, as an example, it is usually encrypted. It is possible to receive unencrypted data when the encryption key is lost.

The communication system according to one aspect of the present invention is a communication system including the communication device according to the present invention and the RFID tag, and the RFID tag is a tag communication unit that receives the encrypted data. The configuration includes a storage unit that stores the encrypted data as it is encrypted.

According to the above configuration, since the RFID tag does not need to be subjected to encryption processing or decryption processing, the cost of the RFID tag can be suppressed.

The communication system according to one aspect of the present invention is a communication system including the communication device and the RFID tag, and the RFID tag includes a tag communication unit for receiving the encrypted data and the encryption key. It is configured to include a second decoding unit that decrypts the encrypted data and a storage unit that stores the decrypted data.

According to the above configuration, the RFID tag stores the unencrypted data. Therefore, in the event that the encryption key is lost, for example, the unencrypted data can be stored by some means. It can be taken out.

In the above configuration, the communication system according to one aspect of the present invention may include a second encryption unit that encrypts the data read from the storage unit by using the encryption key. Often, the tag communication unit may have a function of transmitting the encrypted data to the communication device.

According to the above configuration, the RFID tag can encrypt the data inside the tag and transmit the encrypted data to the communication device.

The communication system according to one aspect of the present invention is the communication system according to the present invention and the communication system including the RFID tag, and the RFID tag includes the tag communication unit for transmitting the encrypted data and the RFID tag. A mode switching unit that switches between a first mode in which data transmitted by the tag communication unit is transmitted in an encrypted state and a second mode in which data is transmitted in an unencrypted state may be provided.

According to the above configuration, it is possible to switch the data transmitted from the RFID tag to the communication device between encrypted and unencrypted data. Therefore, even if the encryption key is lost, for example, the unencrypted data can be transmitted from the RFID tag to the communication device.

In the communication system according to one aspect of the present invention, in the above configuration, the encrypted image may be formed as a one-dimensional or two-dimensional code image on the surface of the RFID tag.

According to the above configuration, the communication device can obtain an encryption key for encrypting / decrypting data by optically reading it from the surface of the RFID tag.

The RFID tag according to one aspect of the present invention is a configuration provided in the communication system according to the present invention.

The RFID tag according to one aspect of the present invention uses a tag communication unit for receiving data encrypted with the encryption key and the encryption key, in which an encryption image showing an encryption key is displayed on the surface of the RFID tag. A second decoding unit that decrypts the encrypted data and a storage unit that stores the decrypted data may be provided.

According to the above configuration, the communication device can recognize the encryption key of the data wirelessly transmitted and received to and from the RFID tag by optically reading the encrypted image displayed on the surface of the RFID tag. .. Therefore, unless the encrypted image can be optically read, the data transmitted and received wirelessly cannot be decrypted, so that secure communication with the RFID tag can be realized.

Further, since the encryption key can be notified to the communication device only by displaying the encryption image on the surface of the RFID tag, secure communication can be realized by a simple method without incurring the complexity of the system.

In the above configuration, the communication device according to one aspect of the present invention is from the first encryption unit that encrypts the actual data of the payload portion of the transport layer using the encryption key, or the communication device to be communicated. The configuration may include a first decoding unit that decodes the actual data of the received payload portion of the encrypted transport layer.

According to the above configuration, even if the encryption key related to the encryption process in the data link layer is acquired, the actual data of the payload part of the transport layer cannot be decrypted unless the encrypted image is optically read. It will be. Therefore, it is possible to limit the communication device capable of realizing effective communication to the communication device within the range in which the encrypted image can be optically read.

Further, the communication device according to one aspect of the present invention may be configured to perform wireless communication by Wifi (registered trademark) or Bluetooth (registered trademark) in the above configuration.

According to the above configuration, even in wireless communication by Wifi or Bluetooth, it is possible to set an area narrower than the range in which radio waves can reach as a communicable area.

According to one aspect of the present invention, it is possible to simultaneously realize simplification and improvement of security of a communication system.

It is a block diagram which shows the structure of the communication system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the RFID tag which concerns on Embodiment 1 of this invention. It is a figure which shows typically the situation which the reader / writer which concerns on Embodiment 1 of this invention and an RFID tag communicate with each other. It is a flowchart which shows the flow of processing in the communication system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the schematic structure of the communication system which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the RFID tag which concerns on Embodiment 2 of this invention. It is a flowchart which shows the flow of processing in the communication system which concerns on Embodiment 2 of this invention. It is a flowchart which shows the flow of the mode switching process in the communication system which concerns on this invention. It is a schematic diagram which shows the outline of an example of the communication system which concerns on Embodiment 3 of this invention. It is a perspective view which shows the example which the 2D code is provided on the surface of a Wifi router. It is a schematic diagram which shows the example which the 2D code is provided on the desk arranged in the communication target space of the Wifi router. It is a schematic diagram which shows the example which the one-to-one Wifi communication is performed between the 1st notebook PC and the 2nd notebook PC. It is a flowchart which shows the flow of the processing of Wifi communication in this embodiment. It is a schematic diagram which shows the outline of an example of the communication system which carries out Bluetooth communication. It is a flowchart which shows the flow of process of Bluetooth communication in this embodiment. It is a block diagram which shows the schematic structure of the communication system which includes a notebook PC and a Wifi router.

(Embodiment 1)
Hereinafter, embodiments according to one aspect of the present invention (hereinafter, also referred to as “the present embodiment”) will be described with reference to the drawings.

§1 Application example First, an example of a situation in which the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a communication system 100 according to the present embodiment. As shown in the figure, the communication system 100 includes a reader / writer (communication device) 2 that reads and writes data to an RFID tag 4 as a communication device to be communicated.

The reader / writer 2 has an optical reading unit 24 that optically reads the two-dimensional code 41 from the RFID tag 4 on which the two-dimensional code 41 indicating the encryption key is displayed on the surface, and data encrypted by using the encryption key. Is provided with an RF (Radio Frequency) communication unit (first communication unit) 23 that wirelessly transmits or receives the RFID tag 4.

In this way, the reader / writer 2 recognizes the encryption key of the data wirelessly transmitted / received to / from the RFID tag 4 by optically reading the two-dimensional code 41 displayed on the surface of the RFID tag 4. Can be done. Therefore, unless the two-dimensional code 41 can be optically read, the data transmitted and received wirelessly cannot be decoded. That is, for example, since it is possible to prevent unauthorized reading of information from outside the factory, secure communication with the RFID tag 4 can be realized.

Further, since the encryption key can be notified to the reader / writer 4 only by displaying the two-dimensional code 41 on the surface of the RFID tag 4, secure communication can be realized by a simple method without complicating the system. be able to.

§2 Configuration example (communication system configuration)
The configuration of the communication system 100 will be described in more detail below. As shown in FIG. 1, the communication system 100 includes a reader / writer 2, a PLC (Programmable Logic Controller) 1, which is a higher-level system that comprehensively manages the entire communication system 100, and an RFID tag 4 that transmits / receives data to / from the reader / writer 2. And have. The PLC 1 and the reader / writer 2 are communicated and connected via a communication network. Although not shown, the PLC 1 may be communicated with one or more reader / writers other than the reader / writer 2 and various other control devices. Further, the reader / writer 2 may actually communicate with a plurality of RFID tags 4.

The reader / writer 2 includes an upper communication unit 21, a data processing unit 22, an RF communication unit 23, an optical reading unit 24, and an antenna 25. The host communication unit 21 controls communication with the PLC 1, transmits an instruction from the PLC 1 to the data processing unit 22, and transmits an output from the data processing unit 22 to the PLC 1.

The output destination from the reader / writer 2 is not limited to the PLC 1, and may be any information processing device capable of communicating with the reader / writer 2 via any communication means.

The data processing unit 22 includes a first encryption unit 31 and a first decryption unit 32. The first encryption unit 31 uses an encryption key to perform a process of encrypting the data transmitted to the RFID tag 4. More specifically, the first encryption unit 31 encrypts the actual data of the payload portion of the data frame transmitted to the RFID tag 4.

The first decryption unit 32 performs a process of decrypting the encrypted data received from the RFID tag 4. More specifically, the first decoding unit 32 decodes the actual data of the payload portion of the data frame received from the RFID tag 4. The RF communication unit 23 controls communication of radio waves transmitted and received by the antenna 25.

The optical reading unit 24 performs a process of optically reading the two-dimensional code 41 displayed on the surface of the RFID tag 4. More specifically, the optical reading unit 24 includes an imaging unit 26, and the imaging unit 26 captures the two-dimensional code 41 and captures it as image data. Then, the optical reading unit 24 acquires the encryption key indicated by the image data and transmits it to the data processing unit 22.

The optical reading unit 24 itself or the imaging unit 26 may be provided in a device separate from the main body of the reader / writer 2 and may be arranged at a position away from the main body. In this case, the separate device and the main body of the reader / writer 2 are connected by a wired or wireless communication means. According to such a configuration, the optical reading unit 24 itself or the imaging unit 26 is installed near the place where the RFID tag 4 is arranged, while the main body of the reader / writer 2 is separated from the place where the RFID tag 4 is arranged. It can be installed in a position.

Further, in the present embodiment shown below, an example in which the two-dimensional code 41 is used will be described, but the present invention is not limited to this, and any encrypted image showing the encryption key may be used. For example, the encrypted image may be a one-dimensional barcode, in which case the optical reader 24 serves as a barcode reader. Further, the encrypted image may be an image showing the encryption key as characters, and the optical reading unit 24 may acquire the encryption key by recognizing the captured image data as characters. Further, the encrypted image may be printed on the surface of the RFID tag 4, or a sticker on which the encrypted image is printed may be attached to the surface of the RFID tag 4.

FIG. 2 is a block diagram showing the configuration of the RFID tag 4. As shown in the figure, the RFID tag 4 has a two-dimensional code 41 displayed on its surface, and includes a tag storage unit 42, a tag communication unit (second communication unit) 43, and a tag antenna 44.

The tag storage unit 42 stores data to be held in the RFID tag 4, and is composed of, for example, a non-volatile memory. The tag communication unit 43 controls communication of radio waves transmitted and received by the tag antenna 44.

FIG. 3 is a diagram schematically showing a situation in which the reader / writer 2 and the RFID tag 4 communicate with each other. As shown in the figure, the reader / writer 2 reads the two-dimensional code 41 displayed on the RFID tag 4 located in the readable range by the optical reading unit 24 (not shown in FIG. 3), thereby encrypting. Get the key. Then, the reader / writer 2 performs encryption processing and decryption processing on the data transmitted / received in the wireless communication by using the acquired encryption key. Although not shown, the RFID tag 4 is attached to, for example, a product produced in a factory or a component constituting the product.

Further, the reader / writer 2 is applied to, for example, a gate R / W (reader / writer), a shelf management R / W, and the like. The gate R / W communicates with, for example, an RFID tag 4 attached to a product conveyed by a belt conveyor. That is, the gate R / W has its own arrangement position fixed and communicates with the RFID tag 4 passing through the communication area. This makes it possible to recognize the products conveyed by the belt conveyor. The gate R / W may also have a form in which when a transport vehicle for transporting a product or the like passes through the gate, it communicates with an RFID tag 4 attached to the product loaded on the transport vehicle.

The shelf management R / W communicates with the RFID tag 4 attached to the product placed on the shelf. That is, the shelf management R / W communicates with the RFID tag 4 that has not moved by moving itself by being transported by the user. This makes it possible to recognize what kind of products are placed on the shelves.

(Flow of communication processing)
FIG. 4 is a flowchart showing a processing flow in the communication system 100. (A) in the figure shows the flow of processing in which the reader / writer 2 reads the information stored in the RFID tag 4, and (b) in the figure shows the flow of the process in which the reader / writer 2 reads the information stored in the RFID tag 4 with respect to the RFID tag 4. It shows the flow of the process of writing information.

First, the reading process will be described. The reading process is started when the reader / writer 2 receives a reading instruction command from the PLC1. In step 1 (hereinafter referred to as S1), the reader / writer 2 reads the two-dimensional code 41 displayed on the RFID tag 4 by the optical reading unit 24. Then, the optical reading unit 24 acquires the encryption key by analyzing the read two-dimensional code 41, and transmits the encryption key to the data processing unit 22.

Further, in S2, the reader / writer 2 communicates with the RFID tag 4 by the RF communication unit 23, and receives the data stored in the RFID tag 4 (communication processing). Here, in the RFID tag 4, the tag communication unit 43 reads predetermined data from the tag storage unit 42 and transmits it to the reader / writer 2 in response to a read instruction from the reader / writer 2. In the reader / writer 2, the received data is transmitted to the data processing unit 22. The processes of S1 and S2 may be performed in parallel, or one process may be performed first and the other process may be performed later.

After that, the reader / writer 2 decrypts the received data with the encryption key in S3 (decryption process). More specifically, the first decoding unit 32 of the data processing unit 22 performs a process of decoding the received data received from the RF communication unit 23 by the encryption key received from the optical reading unit 24. The decrypted data decoded by the first decoding unit 32 is transmitted from the data processing unit 22 to the upper communication unit 21, and is transmitted to the PLC 1 by the upper communication unit 21. This completes the reading process.

In the above description, the reading process has been described as an example in which the reader / writer 2 is started by receiving the reading instruction command from the PLC 1, but the reading process is not limited to this. For example, the reading process may be started by receiving an arbitrary trigger signal from an external device. Examples of the arbitrary trigger signal include a signal generated when a button or switch is pressed by a user, a signal based on the detection result of a sensor that detects a predetermined object, and a signal transmitted periodically. .. Further, the reader / writer 2 may be provided with a member that generates the trigger signal as described above.

Next, the writing process will be described. The writing process is started when the reader / writer 2 receives a writing instruction command from the PLC1. In S11, the reader / writer 2 reads the two-dimensional code 41 displayed on the RFID tag 4 by the optical reading unit 24. Then, the optical reading unit 24 acquires the encryption key by analyzing the read two-dimensional code 41, and transmits the encryption key to the data processing unit 22.

Next, in S12, the reader / writer 2 performs a process of encrypting the data to be written in the RFID tag 4 with the acquired encryption key. More specifically, the higher-level communication unit 21 performs encryption processing on the data to be written received from the PLC 1 based on the encryption key acquired by the first encryption unit 31.

Next, in S13, the reader / writer 2 communicates with the RFID tag 4 by the RF communication unit 23, and transmits the encrypted data to which the encryption processing has been performed to the RFID tag 4 (communication processing). In S14, the RFID tag 4 receives the encrypted data and records the received encrypted data as it is (recording process). More specifically, the tag communication unit 43 performs a process of recording the received encrypted data in the tag storage unit 42. This completes the writing process.

(Embodiment 2)
Other embodiments of the present invention will be described below. For convenience of explanation, the same reference numerals will be added to the members having the same functions as the members described in the above embodiment, and the description will not be repeated.

FIG. 5 is a block diagram showing a schematic configuration of the communication system 100 according to the present embodiment. As shown in the figure, the data processing unit 22 further includes a mode selection unit 33. When reading data from the RFID tag 4, the mode selection unit 33 instructs the RFID tag 4 to transmit the encrypted data, the first mode (encryption mode), and the RFID tag 4. Selects one of a second mode (unencrypted mode) instructing the RFID tag 4 to transmit unencrypted data.

The switching to the second mode is executed, for example, when the two-dimensional code 41 in the RFID tag 4 is in a state where it cannot be optically read due to dirt or the like. If the two-dimensional code 41 cannot be optically read, the encrypted data transmitted from the RFID tag 4 cannot be decrypted. For example, when the two-dimensional code 41 can be recovered by cleaning or when the encryption key is backed up by another means, it is possible to take measures for decrypting the encrypted data. However, if the encryption key cannot be recovered by such measures, it becomes impossible to recognize the information recorded on the RFID tag 4.
As a countermeasure against this, the above mode switching function is implemented. That is, when the encryption key cannot be recovered, the above problem can be solved by switching to the second mode and transmitting the unencrypted data from the RFID tag 4. However, in the second mode, unencrypted data is transmitted and received, so that it can be intercepted by a third party. Therefore, the second mode is only for emergency measures, and it is usually preferable that communication is performed in the first mode.

FIG. 6 is a block diagram showing the configuration of the RFID tag 4 according to the present embodiment. As shown in the figure, the RFID tag 4 further includes a second encryption unit 45, a second decryption unit 46, and a mode switching unit 47. The second encryption unit 45 reads unencrypted data (unencrypted data) recorded in the tag storage unit 42 and performs encryption processing with an encryption key. The data (encrypted data) encrypted by the second encryption unit 45 is transmitted to the reader / writer 2 by the tag communication unit 43. That is, the second encryption unit 45 encrypts the actual data of the payload portion of the data frame transmitted to the reader / writer 2.

The second decryption unit 46 performs a process of decrypting the encrypted received data received by the tag communication unit 43 with the encryption key. More specifically, the second decoding unit 46 decodes the actual data of the payload portion of the data frame received from the reader / writer 2. The data decrypted by the second decryption unit 46 (unencrypted data) is recorded in the tag storage unit 42.

The mode switching unit 47 switches whether the transmission data to be transmitted to the reader / writer 2 is encrypted data or unencrypted data based on the instruction from the reader / writer 2. More specifically, when the reader / writer 2 receives an instruction in the first mode, that is, an instruction to transmit encrypted data, the mode switching unit 47 reads the data encrypted by the second encryption unit 45. It is controlled to transmit to the writer 2. Further, when the reader / writer 2 receives an instruction in the second mode, that is, an instruction to transmit unencrypted data, the mode switching unit 47 stores the tag without performing the encryption process by the second encryption unit 45. The unencrypted data recorded in the unit 42 is controlled to be transmitted to the reader / writer 2.

The mode selection unit 33 of the reader / writer 2 may give a transmission instruction in the first mode every time a read process is performed, but the communication system 100 may determine that the default is transmission / reception in the first mode. Good. In this case, transmission / reception may normally be performed in the first mode, and unencrypted data may be transmitted / received only when the reader / writer 2 issues a transmission instruction in the second mode.

(Flow of communication processing)
FIG. 7 is a flowchart showing a processing flow in the communication system 100 according to the second embodiment. (A) in the figure shows the flow of processing in which the reader / writer 2 reads the information stored in the RFID tag 4, and (b) in the figure shows the flow of the process in which the reader / writer 2 reads the information stored in the RFID tag 4 with respect to the RFID tag 4. It shows the flow of the process of writing information.

First, the reading process will be described. The reading process is started when the reader / writer 2 receives a reading instruction command from the PLC1. In S21, the reader / writer 2 reads the two-dimensional code 41 displayed on the RFID tag 4 by the optical reading unit 24. Then, the optical reading unit 24 acquires the encryption key by analyzing the read two-dimensional code 41, and transmits the encryption key to the data processing unit 22.

Next, in S22, the reader / writer 2 transmits a reading instruction to the RFID tag 4 by the RF communication unit 23. In S23, when the RFID tag 4 receives a read instruction from the reader / writer 2, the second encryption unit 45 reads predetermined data from the tag storage unit 42 and performs encryption processing. After that, in S24, the reader / writer 2 communicates with the RFID tag 4 by the RF communication unit 23, and receives the encrypted data subjected to the encryption process from the RFID tag 4 (communication process). Here, in the RFID tag 4, the tag communication unit 43 transmits the encrypted data encrypted by the second encryption unit 45 to the reader / writer 2. In the reader / writer 2, the received data is transmitted to the data processing unit 22. The processes of S21 and S22 to S24 may be performed in parallel, or one process may be performed first and the other process may be performed later.

After that, the reader / writer 2 decrypts the received data with the encryption key in S25 (decryption process). More specifically, the first decoding unit 32 of the data processing unit 22 performs a process of decoding the received data received from the RF communication unit 23 by the encryption key received from the optical reading unit 24. The decrypted data decoded by the first decoding unit 32 is transmitted from the data processing unit 22 to the upper communication unit 21, and is transmitted to the PLC 1 by the upper communication unit 21. This completes the reading process.

Next, the writing process will be described. The writing process is started when the reader / writer 2 receives a writing instruction command from the PLC1. In S31, the reader / writer 2 reads the two-dimensional code 41 displayed on the RFID tag 4 by the optical reading unit 24. Then, the optical reading unit 24 acquires the encryption key by analyzing the read two-dimensional code 41, and transmits the encryption key to the data processing unit 22.

Next, in S32, the reader / writer 2 performs a process of encrypting the data to be written in the RFID tag 4 with the acquired encryption key. More specifically, the higher-level communication unit 21 performs encryption processing on the data to be written received from the PLC 1 based on the encryption key acquired by the first encryption unit 31.

Next, in S33, the reader / writer 2 communicates with the RFID tag 4 by the RF communication unit 23, and transmits the encrypted data to which the encryption processing has been performed to the RFID tag 4 (communication processing). In S34, the RFID tag 4 receives the encrypted data and performs a process of decrypting the received encrypted data (decryption process). More specifically, the tag communication unit 43 transmits the received encrypted data to the second decryption unit 46, and the second decryption unit 46 performs a process of decrypting the encrypted data. After that, in S35, the second decoding unit 46 performs a process of recording the decoded data in the tag storage unit 42. This completes the writing process.

(Mode switching process)
FIG. 8 is a flowchart showing the flow of the mode switching process. First, in S41, the reader / writer 2 receives an instruction to switch from the PLC1 to the second mode, which is the non-encryption mode.

Here, the instruction for switching from the PLC 1 to the second mode is transmitted from the PLC 1 to the reader / writer 2 together with a predetermined password. The mode selection unit 33 of the reader / writer 2 confirms that the received password is a predetermined valid one, and performs the following mode selection process. In this way, by confirming the validity of the mode switching instruction by the password, it is possible to prevent the transmission / reception of unencrypted data by a third party arbitrarily issuing the mode switching instruction.

Upon receiving the instruction to switch to the second mode, the mode selection unit 33 in the reader / writer 2 instructs the RFID tag 4 to transmit unencrypted data in the second mode (unencrypted). The mode) is selected, and the RF communication unit 23 transmits the message to the RFID tag 4 (S42).

When the RFID tag 4 receives the instruction to switch to the second mode (non-encrypted mode), the mode switching unit 47 records it in the tag storage unit 42 without performing the encryption process by the second encryption unit 45. The unencrypted data is controlled to be transmitted to the reader / writer 2. The reader / writer 2 communicates with the RFID tag 4 by the RF communication unit 23, and receives the unencrypted data from the RFID tag 4 (communication process) (S43).

After that, the reader / writer 2 acquires the unencrypted data in S44 and transmits the acquired unencrypted data to the upper communication unit 21. Then, the unencrypted data is transmitted to the PLC1 by the upper communication unit 21. This completes the reading process.

(Modification example)
In the second embodiment described above, the configuration in which the first mode and the second mode can be switched has been described, but the system may not have this mode switching function. That is, the mode selection unit 33 in the reader / writer 2 and the mode switching unit 47 in the RFID tag 4 may not be provided. In this case, secure communication can be realized by transmitting and receiving encrypted data only in the first mode. Further, since the non-encrypted data is recorded in the tag storage unit 42 of the RFID tag 4, when the two-dimensional code 41 cannot be optically read, the tag storage unit 42 is directly read or otherwise recorded. It is possible to read the data that has been created.

Further, in the first embodiment, the RFID tag 4 includes the mode switching unit 47 and the second decoding unit 46 according to the second embodiment, and the reader / writer 2 includes the mode selection unit 33 according to the second embodiment. It may be configured. In this case, normally, the encrypted data is stored in the tag storage unit 42, and the encrypted data is transmitted and received. However, when the encryption key shown in the second embodiment is lost, the mode can be switched to the non-encryption mode. It will be possible. That is, when the mode is switched to the non-encryption mode, the second decryption unit 46 of the RFID tag 4 decrypts the encrypted data stored in the tag storage unit 42 and transmits the unencrypted data to the reader / writer 2. .. As a result, even if the encryption key is lost, the information stored in the RFID tag 4 can be read out.

(Embodiment 3)
Other embodiments of the present invention will be described below. For convenience of explanation, the same reference numerals will be added to the members having the same functions as the members described in the above embodiment, and the description will not be repeated.

(Outline of communication system)
FIG. 9 is a schematic diagram showing an outline of an example of a communication system according to the present embodiment. As shown in the figure, the communication system includes a Wifi (registered trademark) router 150 and a notebook PC 110 as communication devices to be communicated. The notebook PC 110 includes a camera 111 (see FIG. 11), which captures the two-dimensional code 120. The notebook PC 110 can communicate with the Wifi router 150 by Wifi communication.

Here, in the present embodiment, the Wifi router 150 and the notebook PC 110 represent the actual data (hereinafter, referred to as the payload portion) of the payload portion of the transport layer in the data frame transmitted by the Wifi communication by the two-dimensional code 120. It is encrypted with an encryption key. Then, the notebook PC 110 and the Wifi router 150 decrypt the payload portion of the transport layer in the data frame received by the Wifi communication by the encryption key.

On the other hand, as shown in FIG. 9, the notebook PC 110x arranged in the space where the two-dimensional code 120 cannot be visually recognized can receive the radio wave from the Wifi router 150, but the two-dimensional code 120 is used. Cannot be seen. Therefore, it is not possible to decode the payload portion of the transport layer in the data frame received from the Wifi router 150.

That is, according to the above communication system, only the terminal capable of visually recognizing the two-dimensional code 120 can decode the payload portion of the transport layer in the data frame received by the Wifi communication, so that the Wifi communication is more secure. Can be realized.

(Communication system configuration)
FIG. 16 is a block diagram showing a schematic configuration of a communication system 200 including a notebook PC 110 and a Wifi router 150. As shown in the figure, the notebook PC 110 includes a slave unit side control unit 115, a slave unit side communication unit 117, and an optical reading unit 118. Further, the Wifi router 150 includes a master unit side control unit 155 and a master unit side communication unit 157.

The slave unit side control unit 115 is a block that controls processing in the notebook PC 110, and includes a slave unit side encryption unit 1160 and a slave unit side decryption unit 1161. The slave unit side encryption unit 1160 performs a process of encrypting the payload portion of the transport layer in the data frame transmitted to the Wifi router 150 by using the encryption key. The slave unit side decoding unit 1161 performs a process of decrypting the payload portion of the transport layer in the data frame received from the Wifi router 150 by using the encryption key. The slave unit side communication unit 117 performs Wifi communication with the Wifi router 150.

The optical reading unit 118 performs a process of optically reading the two-dimensional code 120. More specifically, the optical reading unit 24 includes a camera 111 (see FIG. 11), which captures the two-dimensional code 120 and captures it as image data. Then, the optical reading unit 118 acquires the encryption key indicated by the image data and transmits it to the slave unit side control unit 115.

The optical reading unit 118 itself or the camera 111 may be provided in a device separate from the main body of the notebook PC 110 and may be arranged at a position away from the main body. In this case, the separate device and the main body of the notebook PC 110 are connected by a wired or wireless communication means. According to such a configuration, the optical reading unit 118 itself or the camera 111 is installed near the place where the two-dimensional code 120 is arranged, while the main body of the notebook PC 110 is separated from the place where the two-dimensional code 120 is arranged. It can be installed in a position.

The master unit side control unit 155 is a block that controls processing in the Wifi router 150, and includes a master unit side encryption unit 1560 and a master unit side decryption unit 1561. The master unit-side encryption unit 1560 uses an encryption key to perform a process of encrypting the payload portion of the transport layer in the data frame transmitted to the notebook PC 110. The base unit side decryption unit 1561 performs a process of decrypting the payload portion of the transport layer in the data frame received from the notebook PC 110 by using the encryption key. The master unit side communication unit 157 performs Wifi communication with the notebook PC 110.

The two-dimensional code 120 indicates an encryption key used when performing encryption processing on the Wifi router 150 and the notebook PC 110, and is arranged in the communication target space together with the Wifi router 150.

(Example)
FIG. 10 shows an example in which the two-dimensional code 120 is provided on the surface of the Wifi router 150. In the case of this example, the payload portion of the transport layer in the received data frame can be decoded only by the notebook PC 110 located at a position where the two-dimensional code provided on the surface of the Wifi router 150 can be imaged by the camera 111. it can.

The two-dimensional code 120 may be printed on the surface of the Wifi router 150, or a sticker on which the two-dimensional code 120 is printed may be attached to the surface of the Wifi router 150. This also applies to the examples shown in FIGS. 11, 12, and 14 below.

FIG. 11 shows an example in which the two-dimensional code 120 is provided on a desk arranged in the communication target space of the Wifi router 150. In the case of this example, the payload portion of the transport layer in the received data frame can be decoded only by the notebook PC 110 existing at a position where the two-dimensional code provided on the desk can be imaged by the camera 111.

In the above example, an example of Wifi communication between the Wifi router 150 and the notebook PC 110 has been described, but it can also be applied to the case where one-to-one ad hoc communication is performed. FIG. 12 shows an example in which one-to-one Wifi communication is performed between the first notebook PC 110A and the second notebook PC 110B. In the example shown in the figure, the two-dimensional code 120 is provided on the surface of the second notebook PC 110B, and the second notebook PC 110B functions as a master unit.

(Flow of communication processing)
FIG. 13 is a flowchart showing the flow of Wifi communication processing in the present embodiment. First, in S51, a handshake is performed between the Wifi router 150 and the notebook PC 110 as a preprocessing for normal Wifi communication. Next, in S52, the notebook PC 110 optically reads the two-dimensional code 120. By this process, the notebook PC 110 acquires the encryption key.

After that, in S53, communication processing is performed between the Wifi router 150 and the notebook PC 110. In the communication process here, the payload portion of the transport layer in the transmitted / received data frame is encrypted by the encryption key. Then, both the Wifi router 150 and the notebook PC 110 recognize the contents of the received data and perform processing by decrypting the payload portion of the transport layer in the received data frame with the encryption key.

In the decryption process of the notebook PC 110 here, it is essential to use the encryption key obtained by the optical reading performed immediately before. This makes it impossible to reuse the encryption key acquired in the past.

When a series of communication processes are completed, the communication disconnection process between the Wifi router 150 and the notebook PC 110 is performed in S54. When the communication is started again, the process from S51 is executed.

(Example of application to Bluetooth (registered trademark) communication)
In the above, the communication system that implements Wifi communication has been described, but it can also be applied to a communication system that implements Bluetooth communication. FIG. 14 is a schematic diagram showing an outline of an example of a communication system that implements Bluetooth communication. As shown in the figure, the communication system includes a Bluetooth master unit 130 and a mobile terminal 140. The mobile terminal 140 includes a camera (not shown), which captures the two-dimensional code 120. The mobile terminal 140 can communicate with the Bluetooth master unit 130 by Bluetooth communication.

Here, the Bluetooth master unit 130 and the mobile terminal 140 encrypt the payload portion of the transport layer in the data frame transmitted by the Bluetooth communication with the encryption key indicated by the two-dimensional code 120. Then, the Bluetooth master unit 130 and the mobile terminal 140 decrypt the payload portion of the transport layer in the data frame received by the Bluetooth communication by the encryption key.

On the other hand, as shown in FIG. 14, the mobile terminal 140x arranged in the space where the two-dimensional code 120 cannot be visually recognized can receive the radio wave from the Bluetooth master unit 130, but the two-dimensional code 120 cannot be visually recognized. Therefore, it is not possible to decode the payload portion of the transport layer in the data frame received from the Bluetooth master unit 130.

That is, according to the above communication system, only the terminal capable of visually recognizing the two-dimensional code 120 can decode the payload portion of the transport layer in the data frame received by Bluetooth communication, so that more secure Bluetooth communication can be performed. Can be realized.

Since the configurations of the Bluetooth master unit 130 and the mobile terminal 140 are basically the same as the configurations of the notebook PC 110 and the Wifi router 150 described with reference to FIG. 16, the description thereof will be omitted here.

(Flow of communication processing)
FIG. 15 is a flowchart showing a flow of processing of Bluetooth communication in the present embodiment. First, in S61, pairing is performed between the Bluetooth master unit 130 and the mobile terminal 140 as a pre-process for normal Bluetooth communication. Next, in S62, the mobile terminal 140 performs optical reading of the two-dimensional code 120. By this process, the mobile terminal 140 acquires the encryption key.

After that, in S63, a communication process is performed between the Bluetooth master unit 130 and the mobile terminal 140. In the communication process here, the payload portion of the transport layer in the transmitted / received data frame is encrypted by the encryption key. Then, both the Bluetooth master unit 130 and the mobile terminal 140 recognize the contents of the received data and perform processing by decrypting the payload portion of the transport layer in the received data frame with the encryption key.

In the decryption process of the mobile terminal 140 here, it is essential to use the encryption key obtained by the optical reading performed immediately before. This makes it impossible to reuse the encryption key acquired in the past.

When a series of communication processes are completed, the communication disconnection process between the Bluetooth master unit 130 and the mobile terminal 140 is performed in S64. When the communication is started again, the process from S61 is executed.

In the above, an example applied to wireless communication by Wifi and Bluetooth is shown, but the present invention is not limited to these, and can be applied to, for example, TransferJet (registered trademark).

[Example of realization by software]
The data processing unit 22 of the reader / writer 2, the master unit side control unit 155 of the Wifi router 150, and the slave unit side control unit 115 of the notebook PC 110 are logic circuits (hardware) formed in an integrated circuit (IC chip) or the like. It may be realized by software, or it may be realized by software.

In the latter case, the reader / writer 2, the Wifi router 150, and the notebook PC 110 include a computer that executes program instructions that are software that realizes each function. The computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. Then, in the computer, the object of the present invention is achieved by the processor reading the program from the recording medium and executing the program. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a “non-temporary tangible medium”, for example, a ROM (Read Only Memory) or the like, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) or the like for expanding the program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 PLC
2 Reader / writer (communication device)
4 RFID tag 21 Upper communication unit 22 Data processing unit 23 RF communication unit (1st communication unit)
24, 118 Optical reading unit 25 Antenna 26 Imaging unit 31 First encryption unit 32 First decoding unit 33 Mode selection unit 41, 120 Two-dimensional code 42 Tag storage unit 43 Tag communication unit (second communication unit)
44 Tag antenna 45 Second encryption unit 46 Second decryption unit 47 Mode switching unit 100 Communication system 111 Camera 115 Slave unit side control unit 117 Slave unit side communication unit (first communication unit)
130 Bluetooth master unit (communication device)
140, 140 x mobile terminal 150 Wifi router (communication device)
155 Master unit side control unit 157 Master unit side communication unit (second communication unit)
1160 Handset side encryption unit (1st encryption unit)
1161 Handset side decoding unit (first decoding unit)
1560 Master unit side encryption unit (1st encryption unit)
1561 Master unit side decoding unit (first decoding unit)
110, 110A, 110B notebook PC (communication device)

Claims (14)

An optical reader that optically reads an encrypted image showing an encryption key,
A communication device including a first communication unit that wirelessly transmits and receives at least one of a data frame in which the actual data of the payload portion is encrypted using the encryption key to the communication device to be communicated. The optical reading unit optically reads the encrypted image from the RFID tag on which the encrypted image showing the encryption key is displayed on the surface of the RFID tag.
The communication device according to claim 1, wherein the first communication unit wirelessly transmits or receives data encrypted by using the encryption key to the RFID tag. The communication device according to claim 2, further comprising a first encryption unit that encrypts the data using the encryption key, or a first decryption unit that decrypts the encrypted data received from the RFID tag. .. A mode selection unit that switches between a first mode for receiving the encrypted data from the RFID tag and a second mode for receiving the unencrypted data from the RFID tag when reading the data from the RFID tag. With
The communication according to claim 2 or 3, wherein the mode selection unit instructs the RFID tag from the first communication unit to transmit the unencrypted data at least in the second mode. apparatus. The communication device according to claim 2 or 3,
A communication system including the RFID tag.
The RFID tag is
The second communication unit that receives the encrypted data and
A communication system including a storage unit that stores the encrypted data in an encrypted state. The communication device according to claim 2 or 3,
A communication system including the RFID tag.
The RFID tag is
The second communication unit that receives the encrypted data and
A second decryption unit that decrypts the encrypted data using the encryption key,
A communication system including a storage unit for storing decoded data. The RFID tag includes a second encryption unit that encrypts the data read from the storage unit using the encryption key.
The communication system according to claim 6, wherein the second communication unit transmits the encrypted data to the communication device. The communication device according to claim 4 and
A communication system including the RFID tag.
The RFID tag is
The second communication unit that transmits the encrypted data and
A communication system including a mode switching unit that switches between a first mode in which data transmitted by the second communication unit is transmitted in an encrypted state and a second mode in which data is transmitted in an unencrypted state. The communication system according to any one of claims 5 to 8, wherein the encrypted image is formed as a one-dimensional or two-dimensional code image on the surface of the RFID tag. An RFID tag included in the communication system according to any one of claims 5 to 9. An encrypted image showing the encryption key is displayed on the surface of the RFID tag.
The second communication unit that receives the data encrypted with the encryption key,
A second decryption unit that decrypts the encrypted data using the encryption key,
An RFID tag including a storage unit for storing decrypted data. The actual data of the payload part of the transport layer is the actual data of the payload part of the encrypted transport layer received from the first encryption unit that encrypts the actual data of the payload part of the transport layer using the encryption key or the communication device to be communicated. The communication device according to claim 1, further comprising a first decoding unit that decodes the data. The communication device according to claim 12, wherein wireless communication is performed by Wifi (registered trademark) or Bluetooth (registered trademark). An optical reading step that optically reads the encrypted image showing the encryption key,
A communication device including a first communication step in which the actual data of the payload portion wirelessly transmits and receives a data frame encrypted using the encryption key to the communication device to be communicated. Control method.

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