Method for signing a device report

Abstract

The invention relates to a method for signing a device report (22) for a field device (10), having the steps of: • - providing a system comprising a field device (10), a user device (20), and a cloud server (30), said cloud server (30) having a private key (34), • - reading field device data and field device information from the field device (10) by means of the user device (20), • - generating a device report (22) for the field device (10) on the basis of the field device data and the field device information by means of the user device (20) , • - connecting the user device (20) to the cloud server (30), • - transmitting the device report (22) from the user device (20) to the cloud server (30), • - signing the device report (22) using the private key (34) by means of the cloud server (30) such that a device report certificate (35) is produced, and • - transmitting the device report certificate (35) from the cloud server (30) to the user device (20).

Description

[0001] Procedure for signing a device report

[0002] The invention relates to a method for signing a device report.

[0003] Field devices used in industrial plants are already known from the state of the art. Field devices are widely used in process automation technology, as well as in manufacturing automation technology. Field devices are all devices used close to the process and that provide or process-relevant information. Field devices are used to record and / or influence 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, level measurement, etc. and record the corresponding process variables such as pressure, temperature, conductivity, pH value, level, flow, etc. Actuators are used to influence process variables.These include, for example, pumps or valves that can influence the flow of a fluid in a pipe or the fill level in a container. In addition to the previously mentioned measuring devices and actuators, field devices also include remote I / Os, wireless adapters, and generally devices located at the field level.

[0004] A large number of such field devices are produced and distributed by the Endress+Hauser Group.

[0005] In modern industrial plants, field devices are usually connected to higher-level units via communication networks such as field buses (Profibus®, Foundation® Fieldbus, HART®, etc.). These higher-level units are usually control systems (DCS) or control units such as a PLC (programmable logic controller). The higher-level units are used, among other things, for process control, process visualization, process monitoring and for commissioning 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 possibly several) higher-level units. In addition, data transmission from the higher-level unit to the field devices via the bus system is also required, in particular for the configuration and parameterization of field devices and for controlling actuators.

[0006] Mobile operating devices are often used to operate field devices (e.g., parameterize or retrieve data). These are connected to a field device either wired (e.g., via a service interface) or wirelessly (e.g., via Bluetooth). Examples of operating devices include laptops, mobile devices such as smartphones or tablets, or central asset management stations.

[0007] To operate the field devices, appropriate operating programs (operating tools) are required. These programs run either independently on the higher-level units or on the mobile operating devices (Endress+Hauser FieldCare, PACTware, AMS Fisher-Rosemount, PDM Siemens) or are integrated into control center applications (Siemens PCS7, ABB Symphony, Emerson Delta V). The term "operating" includes, among other things, parameterizing the field device, updating the field device, and / or querying and visualizing process data and / or diagnostic data from the field device.

[0008] The integration of field devices into such operating programs is achieved via device drivers or device descriptions. These are provided by the device manufacturers so that the higher-level units, or the operating programs running on these higher-level units, can recognize and interpret the meaning of the information provided 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.

[0009] For comprehensive operation of field devices, special device drivers, so-called DTMs (Device Type Managers), are available. These drivers comply with the FDT (Field Device Tool) specifications, or FDI packages in the FDI environment. 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.

[0010] Device drivers offer the ability to evaluate, diagnose, and / or verify specific device functionalities. Many modern field devices, for example, enable self-tests, such as those within the "heartbeat" (a self-test functionality or SIL functionality implemented in the applicant's field devices). The results of these self-tests, evaluations, etc., are output by the device driver in a report. This driver receives the relevant report parameters, i.e., test results, device status, etc. The report is sent directly to a printer and printed out in physical form. The report is processed, for example, by service personnel, who perform a visual inspection of the report and then sign it. After the signature has been received, the report is scanned or physically stored.

[0011] A method for creating such reports is known, for example, from DE 102021 124 249 A1. However, a disadvantage of this method is that creating and storing physical reports is time-consuming. Therefore, the creation of electronic reports is proposed in the prior art. However, the problem with this approach is that the authenticity of the report cannot currently be guaranteed.

[0012] It is therefore an object of the invention to provide a method which enables a secure, authentic and simple creation of a device report.

[0013] This object is achieved according to the invention by a method for signing a device report of a field device according to claim 1.

[0014] The method according to the invention comprises:

[0015] Providing a system with 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,

[0016] Connecting the user device to the cloud server,

[0017] Sending the device report from the user device to the cloud server,

[0018] Signing the device report with the private key by the cloud server, creating a device report certificate,

[0019] Sending the device report certificate from the cloud server to the user device.

[0020] The method according to the invention makes it possible to create a device report whose authenticity can be reliably verified. Furthermore, the creation of the device report is secure and simple.

[0021] According to one embodiment of the invention, identification of the user device takes place when connecting the user device to the cloud server.

[0022] According to a further embodiment of the invention, the user device further comprises a public key and the user device verifies the device report certificate using the public key.

[0023] According to one embodiment of the invention, the cloud server is integrated into a local network.

[0024] The above-mentioned object is further achieved by a method for signing a device report of a field device according to claim 5.

[0025] The method according to the invention comprises:

[0026] Providing a system with 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,

[0027] Connecting the field device to the cloud server,

[0028] Sending the device report from the field device to the cloud server,

[0029] Signing the device report with the private key by the cloud

[0030] Server, so that a device report certificate is created,

[0031] Sending the device report certificate from the cloud server to the user device.

[0032] The above-mentioned object is further achieved by a method for signing a device report of a field device according to claim 6.

[0033] The method according to the invention comprises:

[0034] Providing a system comprising 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,

[0035] Creating a device report of the field device by the field device based on field device data and field device information,

[0036] Connecting the field device to the user device,

[0037] Sending the device report from the field device to the user device,

[0038] Connecting the user device to the cloud server,

[0039] Sending the device report from the user device to the cloud server,

[0040] Signing the device report with the private key by the cloud

[0041] Server, so that a device report certificate is created,

[0042] Sending the device report certificate from the cloud server to the user device.

[0043] The above-mentioned object is further achieved by a method for signing a device report of a field device according to claim 7.

[0044] The method according to the invention comprises:

[0045] Providing a system comprising 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,

[0046] Reading field device data and field device information from the field device by the cloud server,

[0047] Creating a device report of the field device by the cloud server based on the field device data and the field device information,

[0048] Signing the device report with the private key by the cloud server, creating a device report certificate,

[0049] Sending the device report certificate from the cloud server to the user device.

[0050] The invention is explained in more detail with reference to the following description of the figures. They show:

[0051] - Fig. 1 : a schematic representation of a field device, a user device and a cloud server,

[0052] - Fig. 2: a schematic representation of the method according to the invention,

[0053] - Fig.3: a schematic representation of the interactions between the field device, the user device and the cloud server.

[0054] Figure 1 shows a system 100 comprising a field device 10, a user device 20, and a cloud server 30. The system 100 enables the creation of a secure and authenticatable device report 22 for the field device 10.

[0055] The field device 10 comprises a sensor, for example a pH sensor, a conductivity sensor, or another sensor (not shown). Furthermore, the field device 10 comprises a transmitter connected to the sensor and 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 via HART. According to an alternative embodiment, the field device 10 is suitable for creating a device report 22 and sending it to the cloud server 30 via the first communication unit 11 (dashed arrow in Figure 1).

[0056] The user device 20 is, for example, a tablet, smartphone, or a PC with FieldCare software. The user device 20 comprises a second communication unit 21, which enables internet-capable and / or intranet-capable communication. The user device 20 preferably has user information, which makes it possible to identify the user of the user device 20. When starting the user device 20, a password must preferably be entered to prevent an unauthorized user from using the user device 20. The user information includes, for example, a user number, a user name, or information about the current shift of the maintenance personnel, or information about the user's customer organization.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 server 30, whereby the access point 33 is understood to mean merely a communication unit 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 similar, or another communication module, such as a wired communication module suitable for communicating via HART. The second communication unit 21 can also comprise multiple communication means, for example a Bluetooth module and an LTE module. The user device 20 is suitable for creating the device report 22 for the field device 10. The method for creating the device report 22 will be discussed in detail below.The user device 20 further includes a public key 24 for verifying the device report 22. The public key 24 is a cryptographic key. The public key 24 is publicly accessible and can be downloaded, for example, from the website of the manufacturer of the field device 10.

[0057] The cloud server 30 has an access point 33 and a private key 34.

[0058] The access point 33 is, for example, a WLAN antenna or a cellular antenna, or a cable input, each of which enables access to the Internet or another network. As mentioned above, the access point 33 can also be another communications unit, for example, a wired network. The cloud server 30 preferably has a database (not shown). The database particularly comprises a user database and a device database. The user database stores, for example, data for authenticating user information and user accounts. The device database stores, for example, data for authenticating field device information and a list of the field devices assigned to the user account.

[0059] The private key 34 is a cryptographic key known only to the cloud server 30. The private key 34 is complementary to the public key 24 and enables the signing of a document, in particular a device report 22. The signed device report 22 is called the device report certificate 35. The private key 34 is stored on the cloud server 30 in a secure location that is inaccessible to third parties. The advantage of storing the private key 34 on the cloud server 30 is that it prevents unauthorized access to the private key 34.

[0060] The private key 34 is preferably protected on the cloud server 30 by an HSM module, so the private key 34 is never stored in plain text on the cloud server 30. This is a special hardware that stores the keys in a secure memory and only makes them usable from outside, but the key itself never leaves the secure memory.

[0061] In addition, role-based access restrictions are preferably implemented on the cloud server 30, which prevent unauthorized persons from accessing the private key 34.

[0062] The private key 34 is provided by the manufacturer of the field device 10 in the cloud server 30, enabling authentication of the device report 22 of the field device 10 using the device report 22 signed with 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 Figure 2.

[0063] First, the system 100 described above, including the field device 10, the user device 20, and the cloud server 30, is deployed. All components of the system 100 are operational. The user has activated the user device 20, i.e., logged in if the user device 20 has such a login function. Preferably, the user is also logged in to the cloud server 30, i.e., identified or authenticated.

[0064] Subsequently, the user device 20 is connected to the field device 10 (see Figure 2, S1). 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 between the user device 20 and the field device 10 is established via a cable connection.

[0065] The device report 22 of the field device 10 is then created by the user device 20.

[0066] Creating the device report 22 involves reading the field device data FD and the field device information Fl from the field device 10 by the user device 20 (see Figure 2, S2). The data reading is also represented, for example, by the arrow between the field device 10 and the user device 20 in Figure 1. The user device 20 evaluates the field device data FD and the field device information Fl 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.

[0067] According to this first embodiment, the device report 22 is thus created by the user device 20. Next, the user device 20 is connected to the cloud server 30 (see Figure 2, S3). The connection is established by means of the second communication unit 21 described above and the access point 33 of the cloud server 30. The connection is preferably a wireless internet connection via a mobile network, or a wired connection, for example, via a local network or an intranet. When the user device 20 is connected to the cloud server 30, identification preferably occurs, i.e., the user logs into their user account in the database of the cloud server 30. This prevents a device report certificate from being created for counterfeit field devices.

[0068] Then the device report 22 is sent from the user device 20 to the cloud server 30 (see Figure 2, S4) and double arrow in Figure 1 .

[0069] The device report 22 is then signed with the private key 34 by the cloud server 30, creating a device report certificate 35 (see Figure 2, S5). The device report certificate 35 includes the device report 22, which was signed with the private key 34. The device report certificate 35, together with the public key 24, enables a user to recognize that the device report certificate 35 is an authentic document that actually originates from the field device 10. A user uses the public key 24 to decrypt the device report certificate 35 created with the private key 34. The signature created by the private key 34 is preferably visible in the file properties of the device report certificate 35.

[0070] The device report certificate 35 is then sent from the cloud server 30 to the user device 20 (see Figure 2, S6) as well as the double arrow in Figure 1. A copy of the device report certificate 35 can, of course, remain on the cloud server 30 and, for example, be assigned to the user's user account.

[0071] 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 credible. According to an alternative embodiment, the device report 22 is created on the field device 10 and sent to the cloud server 30 via the first communication unit 11 (see dashed arrow in Figure 1). All subsequent steps up to receipt on the user device 20 are identical to the embodiment first described above.

[0072] According to an alternative embodiment, the device report 22 is created on the field device 10 and sent to the user device 20 via 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 up to receipt on the user device 20 are identical to the embodiment first described above.

[0073] According to an alternative embodiment, field device data FD and field device information Fl are read from field device 10 by cloud server 30 (dashed arrow in Figure 1). Subsequently, a device report 22 of field device 10 is created by cloud server 30 based on field device data FD and field device information Fl. All subsequent steps up to receipt on user device 20 are identical to the first-described embodiment.

[0074] List of reference symbols

[0075] 10 field device

[0076] 11 first communication unit

[0077] 20 user devices

[0078] 21 second communication unit

[0079] 22 Device report

[0080] 24 public keys

[0081] 30 cloud servers

[0082] 31 Database

[0083] 32 Analysis Unit

[0084] 33 access points

[0085] 34 private keys

[0086] 35 Device Report Certificate

[0087] 100 systems

[0088] Fl field device information

[0089] FD field device data

Claims

Patent claims 1. 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 (Fl) 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 (Fl), - 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).

2. The method according to claim 1, wherein an identification of the user device (20) takes place when the user device (20) is connected to the cloud server (30).

3. The method according to claim 1 or 2, wherein the user device (20) further comprises a public key (24) and the user device (20) verifies the device report certificate (35) using the public key (24).

4. The method according to claim 1 to 3, wherein the cloud server (30) is integrated into a local network.

5. 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), - creating a device report (22) of the field device (10) by the field device (10) based on field device data (FD) and field device information (Fl), - 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) to create a device report certificate (35), - Sending the device report certificate (35) from the cloud server (30) to the user device (20).

6. 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), - creating a device report (22) of the field device (10) by the field device (10) based on field device data (FD) and field device information (Fl), - 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) to create a device report certificate (35), - Sending the device report certificate (35) from the cloud server (30) to the user device (20).

7. 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 (Fl) from the field device (10) by the cloud server (30), - Creation of 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 (Fl), - 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).

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