# Green Care Achievement Based on Aquaponics Combined with Human-Computer Interaction
## 3 The Proposed System
### Security of SGCS  
[PERSON] et al. [51] pointed out that the security of IoMT equipment includes the two categories of medical equipment and health information. The information security risk levels of these two categories should be distinguished, and varying degrees of risk control should be established. The risk control of medical equipment should be stricter and precise, mainly because if the medical equipment is hacked and the equipment is interrupted, the patient's life may be at risk. The fuzzy AHP-TOPSIS method proposed by [PERSON] et al. can classify medical devices and health information, establishing varying degrees of risk control. Although the SGCS equipment described in this study is not medical equipment,  
Figure 4: The integration of SGCS. we used the MQTT server account, password and release MQTT Topic for security control, with health information protected with token key, timestamp, and API key signature. The cloud server security, communication information security, push notification security, data packet format, and data packet verification procedures of the proposed SGCS are explained below. * Security of Cloud Servers: SGCS cloud hosting includes a firewall server, API service server, database server, and MQTT server. All sensor data in the SGCS environment must call the RESTful API on the cloud for transmission, and only after filtering the approved IP through the firewall can the data be sent to the API service host to access the database host. Every RESTful API service on the cloud will be checked for communication security. * Security of Communication Information and Data: The sensor data in the SGCS environment must call the RESTful API on the cloud through the Wi-Fi or NB-IoT communication protocol, and the transmitted data packet must contain a token key, call timestamp, API key signature, and data. The token key is the universally unique identifier (UUID) of the microcontroller unit (MCU) device, the call timestamp is the timestamp associated with a call to the RESTful API, and the API key signature is the result of SHA512 hashing with data after formatting as a string. Data are expressed in the JavaScript object notation (JSON) data interchange format, and the content contains the information to be transmitted. A salt key is the key agreed upon in advance between the cloud server and the edge device MCU. These data exist in the database server and edge device MCU and are mainly used to obfuscate the information during transmission to avoid being obtained by someone with malicious intentions through the packet capture program; then, the RESTful API is called on the cloud according to the packet. * Security of Push Notifications: In this research, the MQTT communication protocol is used to send user message notifications. Any edge device connected to the MQTT server needs to provide an account and password for verification to ensure communication security. The release of different edge device messages will be distinguished according to the difference of MQTT Topic; for example, the format of Topic is \(/SGCS/Device/1118\), which represents the edge device with a UUID of 1118 in the SGCS environment. In order ensure that the published message can be delivered to the edge device, the quality of service (QoS) of the message publication will be executed only once. * Structure of the Data Packet: The data packet is transmitted in JSON data interchange format as follows: \(\{\) _\"Token_Key\" = \(TK\), _\"Call_Timestamp\" = \(TS\), _\"API_Key_Signature\" = \(S\), _\"Data\" = DC_ \(\}\)  
The format is standardized with reference to the principles of communication information and data security. The propose SGCS adopts JSON data interchange format as the packet format, mainly because this format has the advantages of high compatibility, easy reading and modification, and support for multiple data types.