Procedure for signing a device report

Abstract

The invention relates to a method for signing a device report (22) of a field device (10) comprising: - Providing a system (100) with a field device (10), a user device (20) and a cloud server (30), wherein the field device 10 has a first communication unit (11), the user device (20) has a second communication unit (21), and the cloud server (30) has an access point (33) and a private key 34, - Reading field device data (FD) and field device information (FI) from the field device (10) by the user device (20), Creating a device report (22) of the field device (10) by the user device (20) based on the field device data (FD) and the field device information (FI), - Connecting the user device (20) to the cloud server (30), - Sending the device report (22) from the user device (20) to the cloud server (30), - Signing the device report (22) with the private key (34) by the cloud server (30) to create a device report certificate (35), - Sending the device report certificate (35) from the cloud server (30) to the user device (20).

Description

The invention relates to a method for signing a device report.Field devices which are used in industrial plants have already become known from the prior art. In process automation technology and in manufacturing automation technology, field devices are frequently used. Field devices are all devices that are used close to the process and supply or process the process-relevant information. Field devices are thus used for detecting and / or influencing process variables. Measuring devices or sensors are used to record process variables. These are used, for example, for pressure and temperature measurement, conductivity measurement, flow measurement, pH measurement, fill level measurement, etc., and record the corresponding process variables pressure, temperature, conductivity, pH value, fill level, flow rate, etc. Actuators are used to influence process variables. These are, for example, pumps or valves which can influence the flow of a liquid in a pipe or the fill level in a container. In addition to the aforementioned measuring devices and actuators, field devices are also understood to mean remote I / Os, radio adapters or generally devices which are arranged at the field level.A large number of such field devices are produced and sold by the Endress+Hauser group.In modern industrial plants, field devices are generally connected to superordinate units via communication networks such as fieldbuses (Profibus® Foundation® fieldbus, HART® etc.). Normally, the superordinate units are control systems (DCS) or control units, such as an PLC (programmable logic controller). The superordinate units serve, inter alia, for process control, process visualization, process monitoring and also for starting up the field devices. The measured values recorded by the field devices, in particular by sensors, are transmitted via the respective bus system to one (or optionally a plurality of) superordinate unit(s). In addition, data transmission from the superordinate unit via the bus system to the field devices is also required, in particular for the configuration and parameterization of field devices and for the actuation of actuators.For operation (for example. Parameterizing or retrieving data) of the field devices are frequently also used as mobile operating devices. These are connected to a field device by cable (for example via a service interface) or wirelessly (for example via Bluetooth). Operating devices used are, for example, laptops, mobile terminals, such as smartphones or tablets, or a central asset management station.For operating the field devices, corresponding operating programs (operating tools) are necessary, which run either independently on the superordinate units or in the mobile operating devices (Endress+Hauser FieldCare, PACTware, AMS Fisher-Rosemount, PWM Siemens) or else are integrated in applications of the control station (Siemens PCS7, ABB Symphony, Emerson Delta V). The term "serving" is understood to mean, inter alia, a parameterization of the field device, an updating of the field device and / or a querying and visualizing of process data and / or diagnostic data of the field device.Field devices are integrated into such operating programs via device drivers or via device descriptions. These are provided by the device manufacturers so that the superordinate units, or the operating programs running on these superordinate units, can recognize and interpret the meaning of the information supplied by the field devices. Such an operating program, into which the device descriptions or device drivers are loaded, is also referred to as a frame application.For full operation of the field devices, special device drivers, so-called DTMs (Device Type Managers), which conform to the FDT (Field Device Tool) specifications or to FDI packages in the FDI environment, are available. Many field device manufacturers supply corresponding DTMs for their field devices. The DTMs encapsulate all variables and functions of the respective field device and usually offer a graphical user interface for operating the devices within the framework application.The device drivers provide the ability to evaluate, diagnose, and / or verify certain device functionalities. Many modern field devices make possible, for example, a self-test, for example in the context of "heartbeat" (a self-test functionality or SIL functionality implemented in the field devices of the applicant). The result of these self tests, evaluation, etc. is output from the device driver in a report. This receiver receives the relevant report parameters, i.e. test results, device status, etc. The report is in particular sent directly to a printer and printed out in physical form. The report is processed, for example, by the service personnel who visually inspect the report and subsequently sign it. After the signature is completed, the report is scanned in or physically maintained.A method for creating such reports is known, for example, from DE 10 2021 124 249 A1. However, a disadvantage of this method is that the creation and storage of physical reports is complicated. The creation of electronic reports is therefore proposed in the prior art. However, it is problematic here that the authenticity of the report cannot be guaranteed up to now.It is therefore an object of the invention to provide a method which enables a secure, authentic and simple creation of a device report.This object is achieved according to the invention by a method for signing a device report of a field device according to claim 1.The method according to the invention comprises:providing a system having a field device, a user device and a cloud server, wherein the field device 10 has a first communication unit, the user device has a second communication unit, and the cloud server has an access point and a private key 34,reading field device data and field device information from the field device by the user device, creating a device report of the field device by the user device based on the field device data and the field device information,connecting the user device to the cloud server,sending the device report from the user device to the cloud server,signing the device report with the private key by the cloud server, so that a device report certificate arises,sending the device report certificate from the cloud server to the user device.The method according to the invention makes it possible to generate a device report whose authenticity can be checked in a reliable manner. In addition, it is achieved that the creation of the device report is safe and simple.According to an embodiment of the invention, an identification of the user device takes place when connecting the user device to the cloud server.According to another embodiment of the invention, the user device further comprises a public key and the user device checks the device report certificate using the public key.According to an embodiment of the invention, the cloud server is integrated into a local area network.The above-mentioned object is furthermore achieved by a method for signing a device report of a field device according to claim 5.The method according to the invention comprises:providing a system having a field device, a user device and a cloud server, wherein the field device has a first communication unit, the user device has a second communication unit, and the cloud server has an access point and a private key,creating a device report of the field device by the field device based on field device data and field device information,connecting the field device to the cloud server,sending the device report from the field device to the cloud server,signing the device report with the private key by the cloud server, so that a device report certificate arises,sending the device report certificate from the cloud server to the user device.The above-mentioned object is furthermore achieved by a method for signing a device report of a field device according to claim 6.The method according to the invention comprises:providing a system having a field device, a user device and a cloud server, wherein the field device has a first communication unit, the user device has a second communication unit, and the cloud server has an access point and a private key,creating a device report of the field device by the field device based on field device data and field device information,connecting the field device to the user device,sending the device report from the field device to the user device,connecting the user device to the cloud server,sending the device report from the user device to the cloud server,signing the device report with the private key by the cloud server, so that a device report certificate arises,sending the device report certificate from the cloud server to the user device.The above-mentioned object is furthermore achieved by a method for signing a device report of a field device according to claim 7.The method according to the invention comprises:providing a system having a field device, a user device and a cloud server, wherein the field device has a first communication unit, the user device has a second communication unit, and the cloud server has an access point and a private key,reading field device data and field device information from the field device by the cloud server,creating a device report of the field device by the cloud server based on the field device data and the field device information,signing the device report with the private key by the cloud server, so that a device report certificate arises,sending the device report certificate from the cloud server to the user device.The invention is explained in more detail with reference to the following description of the figures. The following are shown:FIG. 1 : shows a schematic illustration of a field device, a user device and a cloud server,FIG. 2 is a schematic illustration of the method according to the invention,FIG. 3 : shows a schematic illustration of the interactions between the field device, the user device and the cloud server.FIG. 1 shows a system 100 comprising a field device 10, a user device 20 and a cloud server 30. The system 100 enables a secure and authenticable device report 22 to be generated for the field device 10.The field device 10 includes a sensor, for example a pH sensor, a conductivity sensor or another sensor (not shown). In addition, the field device 10 comprises a transmitter which is connected to the sensor and is suitable for processing the sensor data generated by the sensor (not shown). The field device 10 comprises a first communication unit 11, for example a Bluetooth module, a WLAN module or another communication module, such as a wired communication module, which is suitable for communicating by HART.According to an alternative embodiment, the field device 10 is suitable for creating a device report 22 and for sending it to the cloud server 30 by means of the first communication unit 11 (dashed arrow in FIG. 1 ).The user device 20 is, for example, a tablet, smartphone or else a PC with FieldCare software. The user device 20 comprises a second communication unit 21 which enables an Internet-capable and / or intranet-capable communication. The user device 20 preferably has user information that enables the user of the user device 20 to be identified. Preferably, when starting the user device 20, password input is necessary to prevent an unauthorized user from using the user device 20. The user information comprises, for example, a user number, a user name, or information of the current layer of the maintenance personnel, information about the customer organization of the user. The second communication unit 21 is suitable for connecting to the first communication module of the field device 10 and to the access point 33 of the cloud servers 30, wherein access point 33 is to be understood as meaning only a communication-technology unit which is necessary to access the cloud server 30. For example, the second communication unit 21 is a Bluetooth module, a WLAN module, a mobile radio module such as LTE or the like, or another communication module such as a wired communication module which is suitable for communicating by HART. The second communication unit 21 can also comprise a plurality of communication means, for example a Bluetooth module and an LTE module. The user device 20 is suitable for creating the device report 22 to the field device 10. The method for creating the device report 22 will be discussed in detail below. The user device 20 further comprises a public key 24 to verify the device report 22. The public key 24 is a cryptographic key. The public key 24 is publicly available and can be downloaded, for example, on the Internet site of the manufacturer of the field device 10.The cloud server 30 has an access point 33 and a private key 34. The access point 33 is, for example, a WLAN antenna or a mobile radio antenna or else a cable inlet, which in each case enable access to the Internet or another network. As mentioned above, the access point 33 can also be another communication-technology unit, for example a wired network. The cloud server 30 preferably includes a database (not shown). The database comprises in particular a user bank and a device bank. For example, data for authenticating the user information and user accounts are stored in the user bank. For example, data for authenticating the field device information is stored in the device bank, and a list of the field devices assigned to the user account is stored.The private key 34 is a cryptographic key that is known only to the cloud server 30. The private key 34 is complementary to the public key 24 and makes it possible to sign a document, i.e. in particular a device report 22. The signed device report 22 is called a device report certificate 35. The private key 34 resides in the cloud server 30 at a secure location that is inaccessible by foreign persons. The advantage that the private key 34 is located on the cloud server 30 is that thus an unintentional access to the private key 34 can be prevented.The private key 34 is preferably protected on the cloud server 30 by an HSM module, so the private key 34 is never in plain text on the cloud server 30, which is special hardware which stores the keys in a secure memory and makes them usable only from the outside, but the key itself never leaves the secure memory.In addition, role-based access restrictions are preferably implemented on the cloud server 30, which prevent unauthorized persons from being able to access the private key 34.The private key 34 is provided by the manufacturer of the field device 10 in the cloud server 30, so that authentication of the device report 22 of the field device 10 is possible using the private key 34.The method according to the invention for creating the device report 22 of the field device 10 is discussed below. An exemplary embodiment of the method is shown in FIG. 2.First, it goes without saying that the system 100 described above is provided with the field device 10, the user device 20 and the cloud server 30. All components of the system 100 are ready for function in this case. The user has enabled the user device 20, i.e. logged in there, if the user device 20 has such a log-in function. The user is preferably also logged in, i.e. identified or authenticated, in the cloud server 30.The user device 20 is then connected to the field device 10 (see FIG. 2, S 1 ). The connection is established via the second communication unit 21 and the first communication unit 11. This is preferably a wireless connection, in particular a Bluetooth connection. Alternatively, communication is established between user device 20 and field device 10 via a cable connection.The device report 22 of the field device 10 is then created by the user device 20.The generation of the device report 22 comprises a reading of field device data FD and the field device information FI from the field device 10 by the user device 20 (see FIG. 2, S 2). The reading out of the data is also illustrated, for example, by the arrow between the field device 10 and the user device 20 in FIG. 1. The user device 20 evaluates the field device data FD and the field device information FI and then creates the device report 22, which provides information about the current status of the field device 10. For example, the device report 22 includes whether calibration is necessary due to sensor drift or other reasons that have occurred.The device report 22 is thus created by the user device 20 according to this first embodiment.Next, the user device 20 is connected to the cloud server 30 (see FIG. 2, S 3). The connection is established by means of the above-described second communication unit 21 and the access point 33 of the cloud server 30. The connection is preferably a wireless Internet connection via a mobile radio network, or else a wired connection, for example via a local network or an intranet. When the user device 20 is connected to the cloud server 30, an identification, i.e. a logging-in of the user into the user account thereof, is preferably carried out in the database of the cloud server 30.The device report 22 is then sent from the user device 20 to the cloud server 30 (see FIG. 2, S 4) and the double arrow in FIG. 1.The device report 22 is subsequently signed using the private key 34 by the cloud server 30, so that a device report certificate 35 arises (see FIG. 2, S 5). The device report certificate 35 includes the device report 22 signed by the private key 34. The device report certificate 35 together with the public key 24 enables a user to identify that the device report certificate 35 is an authentic document which actually originates from the field device 10. In this case, a user uses the public key 24 and decrypts the device report certificate 35 created using the private key 34.The device report certificate 35 is then sent from the cloud server 30 to the user device 20 (see FIG. 2, S 6) and the double arrow in FIG. 1.The advantage of a signature with the private key 34 is that this signature proves that the device report 22 or the device report certificate 35 originates from the manufacturer of the field device 10, and the device report certificate 35 is thus suspect.According to an alternative embodiment, the device report 22 is created on the field device 10 and sent to the cloud server 30 by means of the first communication unit 11 (see dashed arrow in FIG. 1 ). All subsequent steps until reception on the user equipment 20 are identical to the first embodiment described above.According to an alternative embodiment, the device report 22 is created on the field device 10 and sent to the user device 20 by means of the first communication unit 11. The device report 22 is then sent from the user device 20 to the cloud server 30. All subsequent steps until reception on the user equipment 20 are identical to the first embodiment described above.According to an alternative embodiment, field device data FD and the field device information FI are read out from the field device 10 by the cloud server 30 (dashed arrow in FIG. 1 ). A device report 22 of the field device 10 is then generated by the cloud server 30 on the basis of the field device data FD and the field device information FI. All subsequent steps until reception on the user equipment 20 are identical to the first-described embodiment.List of reference characters10 Field device 11 First communication unit 20 User device 21 Second communication unit 22 Device report 24 Public key 30 Cloud server 31 Database 32 Analysis unit 33 Access point 34 Private key 35 Device report certificate 100 System FI Field device information FD Field device dataReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2021 124 249 A1

[0010]

Claims

Method for signing a device report (22) of a field device (10), comprising: - providing a system (100) having a field device (10), a user device (20) and a cloud server (30), wherein the field device 10 has a first communication unit (11), the user device (20) has a second communication unit (21), and the cloud server (30) has an access point (33) and a private key 34, - reading out field device data (FD) and field device information (FI) from the field device (10) by the user device (20), creating a device report (22) of the field device (10) by the user device (20) based on the field device data (FD) and the field device information (FI), - connecting the user device (20) to the cloud server (30), sending the device report (22) from the user device (20) to the cloud server (30), signing the device report (22) with the private key (34) by the cloud server (30) so that a device report certificate (35) arises, sending the device report certificate (35) from the cloud server (30) to the user device (20).The method of claim 1, wherein upon connecting the user device (20) to the cloud server (30), an identification of the user device (20) takes place.The method according to claim 1 or 2, wherein the user equipment (20) further comprises a public key (24), and the user equipment (20) checks the equipment report certificate (35) using the public key (24).The method of claims 1 to 3, wherein the cloud server (30) is integrated into a local area network.Method for signing a device report (22) of a field device (10), comprising: - providing a system (100) having a field device (10), a user device (20) and a cloud server (30), wherein the field device (10) has a first communication unit (11), the user device (20) has a second communication unit (21), and the cloud server (30) has an access point (33) and a private key (34), - creating a device report (22) of the field device (10) by the field device (10) on the basis of field device data (FD) and a field device information (FI), - connecting the field device (10) to the cloud server (30), - sending the device report (22) from the field device (10) to the cloud server (30), signing the device report (22) with the private key (34) by the cloud server (30), so that a device report certificate (35) arises, sending the device report certificate (35) from the cloud server (30) to the user device (20).Method for signing a device report (22) of a field device (10), comprising: - providing a system (100) having a field device (10), a user device (20) and a cloud server (30), wherein the field device (10) has a first communication unit (11), the user device (20) has a second communication unit (21), and the cloud server (30) has an access point (33) and a private key (34), - creating a device report (22) of the field device (10) by the field device (10) on the basis of field device data (FD) and a field device information (FI), - connecting the field device (10) to the user device (20), - sending the device report (22) from the field device (10) to the user device (20), connecting the user device (20) to the cloud server (30), sending the device report (22) from the user device (20) to the cloud server (30), signing the device report (22) with the private key (34) by the cloud server (30) so that a device report certificate (35) arises, sending the device report certificate (35) from the cloud server (30) to the user device (20).Method for signing a device report (22) of a field device (10), comprising: - providing a system (100) having a field device (10), a user device (20) and a cloud server (30), wherein the field device (10) has a first communication unit (11), the user device (20) has a second communication unit (21), and the cloud server (30) has an access point (33) and a private key (34), - reading out field device data (FD) and field device information (FI) from the field device (10) by the cloud server (30), - creating a device report (22) of the field device (10) by the cloud server (30) based on the field device data (FD) and the field device information (FI), signing the device report (22) with the private key (34) by the cloud server (30), so that a device report certificate (35) arises, sending the device report certificate (35) from the cloud server (30) to the user device (20).

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