Connection method

Abstract

A connection method. A PIN code of an output device such as a projector can be prevented from being leaked due to eavesdropping and the like, and an information terminal can be connected with the projector. An information terminal (20), which has acquired identification information for identifying an output device (10A), generates a hash value on the basis of the acquired identification information. The information terminal (20) generates a first PIN code on the basis of the generated hash value. The output device (10A) generates a hash value on the basis of identification information of the output device (10A), and generates and displays a second PIN code on the basis of the hash value. The information terminal (20) receives a first input operation for inputting the second PIN code displayed by the output device (10A) to the own device, and transmits a connection request signal to the output device (10A) when the second PIN code input to the own device matches the first PIN code.

Description

Technical Field

[0001] The present disclosure relates to a method for connecting an information terminal to an output device. Background Art

[0002] The projector disclosed in Patent Document 1 displays its identification code on the projection surface in response to a predetermined operation. In the technology disclosed in Patent Document 1, when the projector's identification code is input to an information terminal executing an application for the display system, the information terminal transmits a connection request containing the identification code to the projector. If the connection request received from the information terminal contains the identification code displayed on the projection surface, etc., the projector disclosed in Patent Document 1 permits connection between the information terminal and the communication unit.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2018-152663

[0004] In the technology disclosed in Patent Document 1, the identification code of the projector may be leaked due to eavesdropping on the communication between the information terminal and the projector. Summary of the Invention

[0005] One aspect of the connection method disclosed herein is to connect an output device and an information terminal, the connection method comprising: obtaining, by the information terminal, identification information for identifying the output device; generating, by the information terminal, a hash value based on the identification information obtained by the information terminal; generating, by the information terminal, a first identification code based on the hash value generated by the information terminal; obtaining, by the output device, the identification information; generating, by the output device, a hash value based on the identification information obtained by the output device; generating, by the output device, a second identification code based on the hash value generated by the output device; and accepting, by the information terminal, a first input operation for inputting the second identification code generated by the output device into the information terminal, and sending a connection request signal to the output device when the second identification code input through the first input operation is consistent with the first identification code. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a diagram showing a configuration example of an information system 1 according to one embodiment of the present disclosure.

[0007] Figure 2 1 is a diagram showing an example of the standby screen G1 displayed by the output device 10 .

[0008] Figure 3 1 is a diagram showing a configuration example of the information terminal 20 .

[0009] Figure 4 This is a diagram showing an example of the UI screen G2 displayed on the display device 230 of the information terminal 20 .

[0010] Figure 5 This is a flowchart showing the flow of processing in the connection method according to this embodiment.

[0011] Label Description

[0012] 1: Information system; 10A, 10B, 10: Output device; 20: Information terminal; NW: Network; 210: Processing device; 211: Display control unit; 212: Acquisition unit; 213: Generation unit; 214: Connection control unit; 220: Communication device; 230: Display device; 240: Input device; 250: Storage device; PRA: Program. DETAILED DESCRIPTION

[0013] Various technically preferred limitations are added to the embodiments described below. However, the embodiments of the present disclosure are not limited to the following embodiments.

[0014] 1. Implementation Method

[0015] Figure 1 1 is a diagram showing a configuration example of an information system 1 according to an embodiment of the present disclosure. Figure 1 As shown, the information system 1 includes an output device 10A, an output device 10B, and an information terminal 20. The output device 10 and the information terminal 20 are connected to a network NW such as a wired or wireless LAN (Local Area Network).

[0016] Output device 10A and output device 10B are both display devices that display images, specifically, projectors. Unless it is necessary to distinguish between output device 10A and output device 10B, output device 10A and output device 10B are referred to as "output device 10." Output device 10 is connected to other devices, such as a personal computer, via network NW. Output device 10 projects an image represented by image data supplied from the other connected device onto a projection surface, such as a projection screen, thereby displaying the image. An example of another device in this embodiment is an information terminal 20.

[0017] When the power supply of the output device 10 (at Figure 1 When the device 10 is turned on (not shown in the figure), the output device 10 displays a standby screen on the projection surface for waiting for connection with other devices. Figure 2 FIG. 1 is a diagram showing an example of a standby screen G1 displayed by the output device 10A. Figure 2 As shown, the standby screen G1 includes a character string indicating the name of the output device 10A and a character string indicating a PIN code which is an identification code used when connecting another device to the output device 10 via the network NW. Figure 2As shown, the identification information of the output device 10A is "EB10000" and the PIN code is "2679".

[0018] In the present embodiment, the identification information of the output device 10 is pre-stored in the storage device 250 of the information terminal 20 (the structure of the information terminal 20 will be described in detail later). The output device 10 obtains the identification information of the output device 10 by reading the identification information from the storage device 250. In addition, the output device 10 generates a PIN code according to the following procedure. The output device 10 first generates a character string (hereinafter referred to as a hashed object character string) by linking a specific inherent character string to the identification information of the output device 10. In the present embodiment, "lcp1" is used as the above-mentioned inherent character string. Therefore, in the present embodiment, the output device 10A generates "EB10000lcp1" as the hashed object character string. The above-mentioned inherent character string is pre-stored in the storage device 250 in the same manner as the identification information. In addition, as a specific inherent character string, a character string that changes each time the power of the output device 10 is turned on may be used. For example, a character string representing a date (for example, if it is March 30, 2024, it is 20240330, etc.) or the cumulative number of connections between the output device 10 and the information terminal 20 (for example, if the cumulative number of connections is 200, it is 200, etc.) may be used. Next, the output device 10 generates a hash value by inputting the hashed character string into a specified hash function. Then, the output device 10 selects a specified number of digits (4 in this embodiment) from the beginning of the hash value and arranges these 4 digits from left to right in the order selected, thereby generating a PIN code. In addition, the identification information and inherent character string of the output device 10 may be stored in a storage device within the output device 10 in addition to the storage device 250. In this case, the output device 10 may also read the identification information and inherent character string from the storage device of the output device 10.

[0019] For example, assume that output device 10A inputs the hash target string "EB10000lcp1" into a predetermined hash function, resulting in a hash value of "abb267b9d8a8ee5b3···0." Output device 10A sequentially selects the four digits "2," "6," "7," and "9" from the beginning of this hash value and arranges these four digits from left to right in the order selected, thereby generating a PIN code "2679." The PIN code generated in this manner is displayed on standby screen G1. The PIN code generated by output device 10A is an example of the second identification code in the present disclosure.

[0020] Information terminal 20 is, for example, a personal computer. In this embodiment, when a user of information terminal 20 wishes to connect information terminal 20 to output device 10A, they must launch an application for information system 1 on information terminal 20 and enter a PIN code displayed on standby screen G1 of output device 10A into information terminal 20. This is similar to the technique disclosed in Patent Document 1. In this embodiment, the ability to connect information terminal 20 to output device 10 via network NW without transmitting the PIN code entered into information terminal 20 to output device 10A via network NW is a unique feature of this embodiment. The following description focuses on information terminal 20, which plays a central role in this embodiment.

[0021] Figure 3 2 is a diagram showing a configuration example of the information terminal 20. Figure 3 As shown, the information terminal 20 has a processing device 210, a communication device 220, a display device 230, an input device 240 and a storage device 250. The processing device 210 is one or more processors. Specifically, the processing device 210 is a CPU (Central Processing Unit). The processing device 210 operates according to the program stored in the storage device 250, thereby functioning as the control center of the information terminal 20. The communication device 220 is a device that performs wireless or wired communication with other devices, for example, it has an interface circuit. As a specific example of other devices that communicate with the communication device 220, the output device 10 can be cited. The display device 230 is a device that displays various images under the control of the processing device 210, for example, a liquid crystal display. The input device 240 has an operating element such as a numeric keypad, and provides data indicating the content of the user's operation on the operating element to the processing device 210.

[0022] The storage device 250 is a recording medium that can be read by the processing device 210. The storage device 250 includes, for example, a non-volatile memory and a volatile memory. The non-volatile memory is, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), or an EEPROM (Electrically Erasable Programmable Read Only Memory). The volatile memory is, for example, a RAM (Random Access Memory). The above-mentioned inherent character string (i.e., "lcp1") and various programs are stored in the non-volatile memory of the storage device 250. As an example of various programs stored in the non-volatile memory, a kernel program and a program PRA can be cited. In Figure 3 The kernel program is omitted in the figure. The kernel program is a program for causing the processing device 210 to implement an OS (Operating System).

[0023] The processing device 210, triggered by the start of power supply to the information terminal 20, reads the kernel program from the non-volatile memory to the volatile memory and starts executing the kernel program that has been read. The processing device 210, which operates according to the kernel program, reads the program that has been instructed to start from the non-volatile memory to the volatile memory by operating the input device 240 and executes the program that has been read. For example, when the start of the program PRA is instructed, the processing device 210 reads the program PRA from the non-volatile memory to the volatile memory and starts executing the program PRA that has been read from the volatile memory. The program PRA is an application program for the information system 1. The processing device 210, which operates according to the program PRA, acts as Figure 3 The display control unit 211, the acquisition unit 212, the generation unit 213, and the connection control unit 214 shown in FIG. Figure 3 The display control unit 211 , the acquisition unit 212 , the generation unit 213 , and the connection control unit 214 shown are software modules implemented by causing the processing device 210 to operate according to the program PRA. Figure 3 The functions of the display control unit 211 , the acquisition unit 212 , the generation unit 213 , and the connection control unit 214 are as follows.

[0024] The display control unit 211 displays a UI screen G2 on the display device 230 , prompting input of various information for connecting the information terminal 20 to the output device 10 . Figure 4 FIG is a diagram showing an example of the UI screen G2. Figure 4 As shown, the UI screen G2 includes an input box A1 and an input box A2. The input box A1 is an input area for inputting identification information of a device to be connected to the information terminal 20. When the user of the information terminal 20 wishes to connect the information terminal 20 to the output device 10A, the user inputs the identification information displayed on the standby screen G1 displayed by the output device 10A into the input box A1 through an input operation on the input device 240. The input operation of inputting the identification information into the input box A1 is an example of the second input operation in the present disclosure. The input box A2 is an input area for inputting the PIN code of the device to be connected to the information terminal 20. When the user wishes to connect the information terminal 20 to the output device 10A, the user inputs the PIN code displayed on the standby screen G1 displayed by the output device 10A into the input box A2 through an input operation on the input device 240. The input operation of inputting the PIN code into the input box A2 is an example of the first input operation in the present disclosure.

[0025] The acquisition unit 212 acquires the identification information and PIN code of the device to which the information terminal 20 is to be connected from the input device 240. In the present embodiment, the acquisition unit 212 acquires the identification information inputted by the user from the input device 240. However, the identification information may be acquired from the output device 10 by communicating with the output device 10 using the communication device 220.

[0026] The generation unit 213 generates a PIN code based on the identification information obtained by the acquisition unit 212 and the above-mentioned inherent character string in the same steps as the case in the output device 10. Specifically, the generation unit 213 first generates a hashed object character string by linking the above-mentioned inherent character string to the identification information obtained by the acquisition unit 212. Next, the generation unit 213 generates a hash value by inputting the generated hashed object character string into the same hash function as the hash function in the output device 10. Then, the generation unit 213 selects a specified number (4 in this embodiment) of digits from the beginning of the hash value, and arranges these 4 digits from left to right in the order selected, thereby generating a PIN code. The PIN code generated by the generation unit 213 is an example of the first identification code in the present disclosure.

[0027] The connection control unit 214 determines whether the PIN code generated by the generation unit 213 matches the PIN code obtained by the acquisition unit 212. If the PIN code generated by the generation unit 213 does not match the PIN code obtained by the acquisition unit 212, the connection control unit 214 displays an error message on the UI screen G2, prompting the user to re-enter the identification information and PIN code. Conversely, if the PIN code generated by the generation unit 213 matches the PIN code obtained by the acquisition unit 212, the connection control unit 214 sends a connection request to the output device 10 indicated by the identification information obtained by the acquisition unit 212, without including the PIN code for the device. Upon receiving the connection request via the network NW, the output device 10 unconditionally responds with a connection response, establishing a communication path with the source of the connection request. Once the communication path is established between the output device 10 and the information terminal 20, the information terminal 20 and the output device 10 are connected. The reason the output device 10 unconditionally establishes a communication path with the source upon receiving the connection request is that authentication using the PIN code has already been completed at the source. Since output device 10 does not perform authentication using a PIN code, it is not necessary to include the PIN code of output device 10 in the connection request sent from information terminal 20 to output device 10. Therefore, in this embodiment, the connection request sent by connection control unit 214 does not include the PIN code. Since the connection request sent from information terminal 20 to output device 10 does not include the PIN code, the PIN code will not be leaked even if the connection request is eavesdropped on.

[0028] The above is the configuration of the information terminal 20 .

[0029] Next, refer to Figure 5 Taking the case of connecting the information terminal 20 to the output device 10A as an example, the actions performed by the information terminal 20 and the output device 10A in the connection method for connecting the information terminal 20 to the output device 10A are described. Figure 5 : is a diagram showing the processing flow in the above-mentioned connection method. Figure 5 As shown in FIG, the connection method includes the first display process SA100, the second display process SA110, the acquisition process SA120, the generation process SA130, the connection request process SA140, and the connection response process SA150. Figure 5As shown, the first display process SA100 and the connection response process SA150 are processes executed in the output device 10, and the second display process SA110, the acquisition process SA120, the generation process SA130, and the connection request process SA140 are processes executed in the information terminal 20. The processing contents of each of the first display process SA100, the second display process SA110, the acquisition process SA120, the generation process SA130, the connection request process SA140, and the connection response process SA150 are as follows.

[0030] The first display process SA100 is executed when the output device 10A is powered on. In the first display process SA100, the output device 10A obtains its identification information by reading the identification information from the storage device 250 and generates a PIN code based on the obtained identification information and a predetermined unique character string. Then, in the first display process SA100, the output device 10 displays a standby screen G1 on the projection surface, which includes the obtained identification information and the generated PIN code. In this example operation, the identification information included in the standby screen G1 is "EB10000" and the PIN code is "2679." The user of the information terminal 20 visually understands the identification information and PIN code by viewing the standby screen G1.

[0031] Second display processing SA110 is executed in response to an input operation on input device 240 instructing the activation of program PRA. In second display processing SA110, processing device 210 functions as display control unit 211, displaying UI screen G2 on display device 230. The user of information terminal 20, through input operation on input device 240, inputs the identification information of output device 10A and the PIN code, which they have learned by viewing standby screen G1, into input box A1 and input box A2, respectively. As described above, the user of information terminal 20 has learned the identification information "EB10000" from standby screen G1, and the PIN code "2679" from standby screen G1. Therefore, the user enters "EB10000" into input box A1 and "2679" into input box A2.

[0032] In acquisition process SA120, which is executed following second display process SA110 in information terminal 20, processing device 210 functions as acquisition unit 212. In acquisition process SA120, processing device 210 acquires identification information and a PIN code of the device to which information terminal 20 is connected from input device 240. In this operational example, "EB10000" is entered in input box A1 and "2679" is entered in input box A2. Therefore, processing device 210 acquires "EB10000" as identification information and "2679" as PIN code.

[0033] In generation process SA130, executed following acquisition process SA120 in information terminal 20, processing device 210 functions as generation unit 213. In generation process SA130, processing device 210 concatenates the aforementioned unique character string with the identification information acquired in acquisition process SA120 to generate a hashed character string. As described above, in this example operation, the identification information acquired in acquisition process SA120 is "EB10000" and the unique character string is "lcp1." Therefore, "EB10000lcp1" is generated as the hashed character string. Next, processing device 210 generates a hash value by inputting the hashed character string into the same hash function as that used in output device 10. Processing device 210 then selects a predetermined number (four in this embodiment) of digits from the beginning of the hash value and arranges these four digits from left to right in the order selected to generate a PIN code. In this action example, the hash value "abb267b9d8a8ee5b3···0" is obtained by inputting "EB10000lcp1" as the hash object character string into the specified hash function, and four numbers "2", "6", "7" and "9" are selected from the beginning of the hash value in sequence. These four numbers are arranged from left to right in the order selected to generate the PIN code "2679".

[0034] In connection request processing SA140, executed following generation processing SA130 in information terminal 20, processing device 210 functions as connection control unit 214. In connection request processing SA140, a determination is made as to whether the PIN code generated in generation processing SA130 matches the PIN code obtained in acquisition processing SA120. If they do not match, an error message is displayed on UI screen G2. If they do match, a connection request, excluding the PIN code of the device, is sent to the device indicated by the identification information obtained in acquisition processing SA120. In this example operation, the PIN code obtained in acquisition processing SA120 is "2679," and the PIN code generated in generation processing SA130 is also "2679," so the two PIN codes match. Therefore, in connection request processing SA140 in this example operation, a connection request is sent to the device with identification information "EB10000."

[0035] Connection response processing SA150 is executed by the output device 10 upon receipt of a connection request via the network NW. In connection response processing SA150, the output device 10 unconditionally establishes a communication path with the source of the connection request, establishing a connection between the source and the output device 10. The output device 10 then displays an image represented by image data transmitted from the information terminal 20 via the network NW on the projection surface.

[0036] According to this embodiment, the PIN code generated by the output device 10 is not transmitted or received via the network NW, eliminating the risk of the PIN code being leaked due to eavesdropping on the network NW. Furthermore, according to this embodiment, as long as the identification information of the output device 10, the specific unique character string, and the hash function are not leaked, the PIN code of the output device 10 cannot be accurately generated, thereby preventing the fabrication of the PIN code.

[0037] 2. Deformation

[0038] The above-mentioned embodiment can be modified as follows.

[0039] (1) The output device 10 in the above embodiment is a projector, but it may also be a printer or a scanner. In addition, the information terminal 20 in the above embodiment is a personal computer, but it may also be a smartphone or a tablet terminal. In addition, in the above embodiment, the output device 10 and the information terminal 20 each generate a PIN code based on the identification information and inherent character string of the output device 10. However, it is also possible that the output device 10 and the information terminal 20 each generate a PIN code based only on the identification information of the output device 10, in other words, using the identification information of the output device 10 itself as the hash object character string. Even if the PIN code is generated based only on the identification information of the output device 10, as long as the identification information of the output device 10 and the hash function are not leaked, the PIN code of the output device 10 cannot be accurately generated, and thus the fabrication of the PIN code can be avoided.

[0040] (2) In the above embodiments, the display control unit 211, acquisition unit 212, generation unit 213, and connection control unit 214 are software modules. However, any one, any two, any three, or all of the display control unit 211, acquisition unit 212, generation unit 213, and connection control unit 214 may be hardware modules such as an ASIC (Application Specific Integrated Circuit). Even if at least one of the display control unit 211, acquisition unit 212, generation unit 213, and connection control unit 214 is a hardware module, the same effects as those in the above embodiments can be achieved.

[0041] (3) The program PRA may be manufactured independently or provided for a fee or free of charge. Specific methods for providing the program PRA include providing the program PRA by writing it on a computer-readable recording medium such as a flash ROM, or providing the program PRA by downloading it via a telecommunication line such as the Internet. By operating a general computer according to the program PRA provided in these methods, the computer can function as the information terminal 20 of the above-described embodiment.

[0042] 3. Summary of the Disclosure

[0043] The present disclosure is not limited to the above-mentioned embodiments and variations, and can be implemented in various ways without departing from its main purpose. For example, the present disclosure can also be implemented in the following ways. In order to solve part or all of the problems of the present disclosure, or to achieve part or all of the effects of the present disclosure, the technical features in the above-mentioned embodiments corresponding to the technical features in the various methods described below can be appropriately replaced or combined. In addition, if its technical features are not described as necessary features in this specification, they can be appropriately deleted.

[0044] The following is a summary of the present disclosure.

[0045] Note 1

[0046] The present disclosure provides a connection method for connecting an output device and an information terminal, comprising: obtaining identification information for identifying the output device by the information terminal; generating a hash value by the information terminal based on the identification information obtained by the information terminal; generating a first identification code by the information terminal based on the hash value generated by the information terminal; obtaining the identification information by the output device; generating a hash value by the output device based on the identification information obtained by the output device; generating a second identification code by the output device based on the hash value generated by the output device; and receiving a first input operation for inputting the second identification code generated by the output device into the information terminal, and transmitting a connection request signal to the output device when the second identification code input by the first input operation matches the first identification code. According to this connection method, the second identification code generated by the output device is not transmitted to the information terminal via a communication network, eliminating the risk of the second identification code being leaked due to eavesdropping on the communication network.

[0047] Note 2

[0048] In a more preferred embodiment of the connection method described in Supplementary Note 1, generating a hash value by the information terminal based on the identification information obtained by the information terminal includes: obtaining a unique character string by the information terminal; and generating a hash value based on the identification information obtained by the information terminal and the unique character string obtained by the information terminal; and generating a hash value by the output device based on the identification information obtained by the output device includes: obtaining a unique character string by the output device; and generating a hash value based on the identification information obtained by the output device and the unique character string obtained by the output device. This embodiment improves security compared to a method of generating a hash value based solely on identification information.

[0049] Note 3

[0050] In another preferred embodiment of the connection method according to Supplementary Note 1 or Supplementary Note 2, the output device is a display device that outputs the image by displaying an image, and the connection method further includes: displaying the identification information on the output device; and receiving a second input operation by the information terminal for inputting the identification information displayed by the output device into the information terminal, wherein the information terminal obtains the identification information for identifying the output device by obtaining the identification information input by the second input operation. According to this embodiment, the user can connect the information terminal to the display device by inputting two pieces of information displayed on the display device.

Claims

1. A connection method for connecting an output device and an information terminal, wherein: The connection method comprises: obtaining, by the information terminal, identification information for identifying the output device; Based on the identification information obtained by the information terminal, the information terminal generates a hash value; Based on the hash value generated by the information terminal, the information terminal generates a first identification code; obtaining the identification information by the output device; generating a hash value by the output device based on the identification information obtained by the output device; generating a second identification code by the output device based on the hash value generated by the output device; and The information terminal receives a first input operation for inputting a second identification code generated by the output device into the information terminal, and transmits a connection request signal to the output device when the second identification code input by the first input operation matches the first identification code.

2. The connection method according to claim 1, wherein: Generating a hash value by the information terminal based on the identification information obtained by the information terminal includes: Obtaining a unique character string from the information terminal; and Generate a hash value based on the identification information obtained by the information terminal and the unique character string obtained by the information terminal, Generating a hash value by the output device based on the identification information obtained by the output device includes: Obtaining a unique character string from the output device; and A hash value is generated based on the identification information acquired by the output device and the unique character string acquired by the output device.

3. The connection method according to claim 1, wherein: The output device is a display device that outputs the image by displaying the image, The connection method further comprises: displaying the identification information by the output device; and The information terminal accepts a second input operation for inputting the identification information displayed by the output device into the information terminal, Acquiring identification information for identifying the output device by the information terminal includes acquiring identification information input by the second input operation.

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