QR code display device with one-time password generation function

Abstract

The objective of this invention is to provide a device that operates offline and ensures high security by displaying information including one-time passwords as QR codes. [Solution] This QR code display device 11 with a one-time password generation function comprises a microcomputer 11 that generates one-time passwords, a real-time clock unit 12 that supplies the current time, a display unit 13 that displays authentication information including the one-time password as a QR code, and a storage unit 17 that stores a private key, and is characterized in that it generates a one-time password based on the private key stored in storage unit 17 and the current time, and generates a URL including the one-time password and displays it on display unit 13. With this configuration, this device has the effect of being able to perform authentication with excellent security even though it is a device used in an offline environment not connected to a communication means such as the Internet.

Description

[Technical Field]

[0001] The present invention relates to a device that displays authentication information, and more particularly to a low-power display device that generates a one-time password (TOTP) and displays it as a QR code on electronic paper. [Background technology]

[0002] Conventionally, QR codes (a registered trademark of Denso Wave Inc.) used for authentication have often been provided as printed materials or statically displayed codes, which users would read with a smartphone or other device and authentication would be processed on the server side. However, statically displayed QR codes are easily copied and forwarded by third parties, posing a high risk of fraudulent use. Patent Document 1 describes a technology that uses an authentication method incorporating a one-time password. However, there has been no device capable of sequentially generating and displaying QR codes that can maintain a certain level of security offline. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-71745 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention was devised to solve the problems inherent in the above-mentioned background art, and aims to provide a device that operates offline and ensures high security by displaying information including a one-time password as a QR code. Another challenge is to use low-power electronic paper displays to enable long-term battery-powered use, and to transmit BLE beacons as needed to enable location notifications and app integration. Furthermore, it is an object of the present invention to provide a device that is more convenient by making it possible to transmit the same authentication information as the QR code via NFC communication. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention has the following configuration. a microcomputer having a function of generating a one-time password; a real-time clock unit that supplies the current time to the microcomputer; an electronic paper that displays authentication information including the one-time password as a QR code; a storage unit that stores information including a private key processed by the microcomputer; a power supply unit, The microcomputer generates a one-time password based on the private key stored in the memory unit and the current time, and generates a URL including the one-time password and controls the display of the URL on the electronic paper.

[0006] In addition, in the above QR code display device, The device is characterized by being equipped with an NFC communication unit and an NFC antenna that transmit the authentication information to an external device via NFC communication.

[0007] In addition, in the above QR code display device, The microcomputer generates a URL that includes the authentication information, as well as a serial number, a generation time, and a remaining battery level.

[0008] In addition, in the above QR code display device, The microcomputer controls the BLE transmitter to periodically transmit a BLE beacon signal in which a UUID, transmission intensity, and transmission interval are set.

[0009] In addition, in the above QR code display device, The authentication information is encrypted using the private key. [Effects of the Invention]

[0010] This device is used in an offline environment that is not connected to a communication means such as the Internet, but the generated authentication URL can be read by a user terminal (such as a smartphone) and the server can be accessed via that terminal. In this case, by generating authentication information using time information generated by a real-time clock supply means and including it in the URL, it has the effect of enabling highly secure authentication on the server side connected by the URL. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an external view of a QR code display device with a one-time password generation function according to the present embodiment. [Figure 2] FIG. 2 is a block diagram showing the internal configuration of the device. [Figure 3] 3 is a flowchart showing the operation flow of the present device. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes an embodiment of the present invention with reference to the drawings. Fig. 1 is an external view of a QR code display device (hereinafter referred to as "device") 1 with a one-time password generation function according to this embodiment, and Fig. 2 is a block diagram showing the internal configuration of device 1. The device 1 is configured to provide authentication information used for user authentication and access control in a safe and convenient manner. The device 1 includes a microcomputer 11, an RTC (real-time clock supply means) 12, an electronic paper display unit 13, an electronic paper driving IC 14, an NFC antenna 15, an NFC communication unit 16, a memory unit 17, power supply units 18 and 19, an input voltage monitor 20, and a BLE transmission unit 21.

[0013] The microcontroller 11 periodically generates a one-time password (TOTP) conforming to the RFC6238 standard using time information from the RTC 12 and a private key stored in the memory unit 17. It then generates a URL that embeds the generated TOTP along with the device serial number, the time of generation, remaining battery power, and other information, converts this into a QR code, and displays it on the display unit 13. The display unit 13 is made of electronic paper and does not consume power while displaying the information, enabling long-term battery operation. Furthermore, the same authentication information is stored in the NFC communication unit 16 and can be transmitted to the user's smartphone or other device via the NFC antenna 15. Additionally, the BLE transmitter 21 emits a beacon signal that can be used to notify location information or trigger the activation of a smartphone app. In this way, device 1 is equipped with dual authentication information presentation means, namely, QR code display and NFC transmission, thereby achieving both security and convenience, and is configured as an information display device that can be used for a wide range of purposes thanks to its low-power consumption design.

[0014] The microcomputer 11 is a core component responsible for controlling the device 1, and is a processor that oversees each step of the operation flow shown in Figure 3, which will be described later. The nRF52 / nRF54 series used is a low-power microcontroller that supports Bluetooth Low Energy (BLE), and utilizes its built-in computing power and communication functions to centrally process the generation, conversion, display, and transmission of authentication information ("Bluetooth" is a registered trademark of Bluetooth SIG, Inc.). Specifically, the microcomputer 11 first reads time information from the real-time clock supply means 12 and combines it with the private key stored in the memory unit 17 to calculate a TOTP that complies with the RFC6238 standard.

[0015] The obtained TOTP is converted into a URL along with the serial number, generation time, remaining battery level, etc. The TOTP or information including the serial number, generation time, remaining battery level, etc., in addition to the TOTP is encrypted as necessary. In this embodiment, encryption is performed when the URL template exemplified as an encryption format is used. The microcontroller 11 then converts the URL into a QR code and transmits a drawing command to the display unit 13 via the electronic paper driving IC 14. The same information is also transmitted to the NFC communication unit 16 as a write command, and can be transmitted to an external device via the NFC antenna 15. The microcontroller 11 then instructs the BLE transmission unit 21 to transmit a beacon signal, thereby realizing location information notification and app linkage. In this way, the microcomputer 11 is responsible for sequentially executing a series of processes, such as time synchronization, TOTP generation, data structure conversion, encryption, display control, and communication control, using a software program. The program has a periodic management function and has a loop structure that repeats the above processes at set update intervals. Therefore, the microcomputer 11 is the key to integrating each hardware component in the device 1 and achieving both security and low power consumption.

[0016] The real-time clock (RTC) 12 is a component that provides the current time as the time reference for the device 1, ensuring the accuracy of TOTP generation and operation schedule control. The RTC is configured on an external chip and is constantly powered by a coin battery 18, so the internal time information is maintained even when the main power is off. This allows seamless resumption of operation without losing time information, even after battery replacement or long periods of standby. In the operation flow, the RTC 12 provides the current time in response to a request from the microcomputer 11, and the microcomputer calculates the TOTP based on this time and controls operation by comparing it with the set operation start and end times. The RTC 12 is also a core component essential for maintaining the validity of TOTP authentication and controlling the operation time period, and the accuracy of the RTC is important for consistency with the authentication process on the server side, directly contributing to the security and power saving of the entire device 1.

[0017] The display unit 13 is a device configured with electronic paper that visually presents the generated QR code to the user, and has the major feature of being able to operate with low power consumption. Electronic paper does not require power to maintain the displayed content, and consumes drive power only when updating. Therefore, when a display update command is sent from the microcontroller 11, a new QR code is drawn via the electronic paper driving IC 14, and the display is then maintained while reducing power consumption. In the operation flow, the microcontroller generates and encrypts a URL including the TOTP and accompanying information, converts it into a QR code, and outputs it to the display unit 13. Users can access the server by reading this QR code with a smartphone or other device. Electronic paper is highly visible even in direct sunlight and has a long display life, making it suitable for use in a variety of environments, such as outdoors or at store entrances. Furthermore, its low power consumption allows it to be used for long periods on battery power, contributing to reduced maintenance frequency in industrial applications. The display unit 13 is an important element of the user interface in the device 1 and plays an important role in achieving both security and power saving.

[0018] The electronic paper driver IC 14 is a circuit that receives drawing commands sent from the microcontroller 11 and supplies the appropriate drive voltage and control signals to the display unit 13. Because electronic paper uses a special electrophoretic phenomenon to form images, the drive sequence requires a specific voltage waveform and timing. This driver IC is designed to handle this complex control, so that the microcontroller only needs to send simple display data. In the operation flow, the microcontroller transfers bitmap data in the form of a QR code containing a URL to the driver IC, which then updates the electronic paper. This configuration reduces the processing load on the microcontroller and also reduces power consumption.

[0019] NFC antenna 15 radiates a high-frequency signal output from NFC communication unit 16 into the air, enabling contactless communication with an external terminal. In the operation flow, microcomputer 11 writes authentication information to NFC communication unit 16, which then generates a modulated signal, which is then transmitted to the outside via NFC antenna 15. By simply holding their smartphone over device 1, the user can receive the same authentication information as the QR code, dramatically improving the convenience of authentication.

[0020] The storage unit 17 utilizes the non-volatile memory area of ​​the microcomputer 11 to store various setting information such as the private key, serial number, operating time zone, QR code update cycle, and URL template. This information is the basis for TOTP generation and encryption processing, and plays an important role in the operation of the device 1. The program reads the contents of the storage unit at startup and reflects this information in cycle control and authentication information generation. Due to the non-volatile characteristics of the storage unit, setting information is retained even when the power is turned off, enabling stable long-term operation.

[0021] The storage unit 17 uses a non-volatile area of ​​the microcomputer 11 (e.g., the nRF52 / 54 series built-in Flash) to store various settings that define the operation of the device 1. Examples of setting information include: Serial number (12 digits): 6 digits + 6 digits (e.g., 000001000001) Start time (6 digits): Example: 090000 (starts at 9:00) or 000000 (always on) Operation end time (6 digits): Example: 180000 (ends at 6 p.m.) or 000000 (operates continuously) QR code update cycle (6 digits): Example: 003000 (Updated every 30 minutes) Secret key (31 characters): Common secret key for generating TOTP (e.g., ZG5TFN9UN0VK7N86D540TPM7YYMQSCX) etc.

[0022] In addition, URL templates in the following two formats are also stored. Format (1) Parameter format https: / / www.example.com / view.php?sn1={sn1}&sn2={sn2}&TOTP={TOTP}&ts={ts}&bt={bt} Format (2) Encryption format https: / / www.example.com / view / {encrypt}※ / The {encrypt}* part is a string that combines the serial number, TOTP, time, and remaining battery level, and is XORed with the secret and base64url encoded.

[0023] The power supply unit 18 is a coin battery that keeps the real-time clock supply means 12 running at all times. Because the RTC disables TOTP generation if it stops keeping time, a dedicated independent power supply ensures stable operation. This power supply configuration allows the RTC to continue to keep accurate time even when the device 1 is stopped, and allows for seamless authentication processing even when the device is restarted.

[0024] The power supply unit 19 is the main power source that supplies the power required for the entire device to operate, and is composed of three batteries. This power supply supplies relatively high-power processing such as the electronic paper display, NFC communication, and BLE transmission. The adoption of a battery-powered system increases portability and makes it easy to install in places where it is difficult to secure a power source, such as commercial facilities and event venues.

[0025] The voltage monitor 20 is a circuit that monitors the battery voltage and performs DC-DC conversion as necessary. The program embeds remaining battery information in the authentication URL and transmits it via QR code or NFC communication. This allows the server and users to understand the power status of the device 1 and predict when it will need to be replaced. The DC-DC conversion function also supplies a voltage that allows each component to operate stably.

[0026] The BLE transmitter 21 has the function of transmitting BLE beacon signals such as iBeacon (a registered trademark of Apple Inc.) under the control of the microcontroller 11. Beacons are periodically transmitted in parallel with the authentication information generation process, notifying the user terminal of location information and triggering the launch of an app. This makes it possible to apply it not only as a simple authentication device but also to location-linked services and marketing initiatives. By adopting BLE, a low-power communication standard, continuous operation is achieved without compromising battery life.

[0027] Figure 3 is a flowchart showing the operation flow of the device 1 of the present invention. After powering on, the device 1 provides information for authentication by repeatedly generating a one-time password and displaying and transmitting the information while referencing predetermined saved setting information. Each step is explained below.

[0028] First, in step S1, when a battery is attached to the device 1, the microcomputer 11 obtains from the RTC 12 the current time that is the reference for the internal clock. Next, in step S2, the microcomputer 11 reads out the saved setting information stored in the memory unit 17. This saved setting information includes the serial number, the operating time zone, the QR code update cycle, the secret key for generating TOTP, the URL template, the encryption method, the BLE beacon settings, and the like. In step S3, it is determined whether the current time is within the operating time period defined in the saved setting information. If it is outside the operating time period, in step S4, the device goes into a low-power standby mode and periodically performs a re-determination. On the other hand, if it is within the operating time zone, the microcomputer 11 generates a one-time password (TOTP) conforming to the RFC6238 standard based on the current time of the RTC 12 and the private key stored in the storage unit 17 in step S5.

[0029] In step S6, the voltage monitor 20 measures the remaining battery level and reflects this in the remaining battery level information in the URL. At the same time, if the remaining battery level is low, a warning is displayed and sent. Next, in step S7, a URL is generated that embeds the generated TOTP, serial number, generation time, and remaining battery level information. At this time, the URL format is constructed according to the template (format (1) or format (2)) stored in the memory unit 17.

[0030] If the URL format is the above-mentioned format (2), encryption processing is performed in step S8. For example, an encrypted URL is generated by performing an XOR operation on the TOTP or serial number with a secret key and encoding it in base64url format. Next, in step S9, the URL is converted into a QR code and output to display unit 13. The electronic paper display unit consumes low power, and the QR code is held until the next update. Furthermore, in step S10, the same URL information is written to the NFC communication unit 16, and can be transmitted via the NFC antenna 15 to an external device.

[0031] In step S11, the BLE transmitter 21 transmits a beacon signal in a format such as iBeacon (a registered trademark of Apple Inc.), which enables location linkage and notification linkage with a smartphone app or the like. Finally, in step S12, when the QR code update period defined in the saved setting information has elapsed, the process returns to step S3 and the process is repeated from the time determination again. This allows the device 1 to provide the user with periodically updated QR codes and NFC transmission information in a power-saving and highly secure manner. [Industrial Applicability]

[0032] The device of this invention can provide a variety of authentication methods that combine QR code display and NFC transmission while ensuring security through one-time passwords, making it widely applicable to marketing purposes such as identity authentication for online services, entrance and exit management at stores and facilities, content distribution, and reward points for visiting stores. Furthermore, the low power consumption of electronic paper and its long-term battery-powered operation make it extremely useful industrially as a portable terminal or stationary information display device. [Explanation of symbols]

[0033] 1. QR code display device with one-time password generation function (device) 11 Microcomputer 12 RTC (Real Time Clock) 13 Display section 14 Electronic paper driving IC 15 NFC antenna 16 NFC communication unit 17 Memory section 18 Power supply section 19 Power supply section 20 Voltage Monitor 21 BLE transmitter

Claims

1. a microcomputer having a function of generating a one-time password; a real-time clock unit that supplies the current time to the microcomputer; a display unit that displays authentication information including the one-time password as a QR code (a registered trademark of Denso Wave Inc.); a storage unit that stores information including a private key processed by the microcomputer; a power supply unit, A QR code display device with a one-time password generation function, characterized in that the microcomputer generates a one-time password based on the private key stored in the memory unit and the current time, and controls the generation of a URL including the one-time password and displaying it on the display unit.

2. 2. The QR code display device with one-time password generation function according to claim 1, further comprising an NFC communication unit and an NFC antenna for transmitting the authentication information to an external device by NFC communication.

3. The microcomputer generates a URL including the authentication information, a serial number, a generation time, and a remaining battery level.

3. The QR code display device with a one-time password generating function according to claim 1.

4. 4. The QR code display device with one-time password generation function according to claim 3, wherein the microcomputer controls the BLE transmission unit to periodically transmit a BLE beacon signal in which a UUID, transmission strength, and transmission interval are set.

5. 4. The QR code display device with one-time password generation function according to claim 3, wherein the authentication information is encrypted using the private key.

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