# Privacy-Aware Cloud Architecture for Collaborative Use of Patients' Health Information
## 3 Proposed Architecture
### Architectural Design and Components
There are two methods of requesting and obtaining temporary consent: via mobile phone in the form of a text message or via email confirmation. More information about patient consent is provided further in the paper. **StandardUser Application**  
The proposed system architecture requires a standard application that is installed and runs locally on users' machines. Accessing patients' information stored on the cloud can only happen through a standard user application (UA). Having a unified platform to access patients' information was identified in the case study findings as a desired characteristic of healthcare information systems; therefore, the proposed architecture design employs a standard UA through which users can access information that is stored on the cloud. The UA plays a key role in the proposed system architecture; it facilitates means of standardization in the process of storing, accessing, categorizing, and structuring information. There are three main functions that UA is responsible for: storing, accessing, and updating patient information on the cloud. These functions are performed using buttons that are available on the UA interface; these buttons are ENROL, REQUEST, UPDATE, and RESEARCH. Further explanation about these functions is presented further in the paper. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Full Name** & **D.O. Birth** & **NHI Number** \\ \hline \multirow{3}{*}{ID} & & \multirow{3}{*}{\(S_{\text{KR}}\)} & doc-1 Index \\  & & & doc-2 Index \\  & & & doc-3 Index \\ \hline \multirow{3}{*}{User ID} & \(\square\) & Email \\  & \(\square\) & Phone Number \\ \cline{1-1}  & & User ID \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Information stored on the Requesting Agent for every patient. There are a number of characteristics that UA has that enable it to store, access, and update patients' information on the system. The following are the main characteristics of the UA employed in the proposed system design:  
* Standard presentation and categorization of information  
Categorizing information is one of the UA's functionalities. The application organizes patient information files into three documents (doc-1, doc-2, and doc-3) before they are stored on the cloud. The UA has a standard user interface for all users. Information is accessible when it appears in predetermined fields on the user interface. Information is presented in its associated fields only when it is decrypted. Information fields remain blank when their corresponding files are not decrypted. For example, if a field on the application interface is predetermined for information related to patient mental health, this field remains blank when the logged-in user is not authorized to access the document in which the mental health file exists. * Information pre-processing, encrypting, and decrypting  
The properties of the searchable symmetric encryption (SSE) approach employed in the proposed architectural design are achieved by operations, performed by the UA. The pre-processing operations, together with encryption and decryption operations, are all performed by the UA. The UA is responsible for pre-processing the information by organizing it and encrypting it following the SSE approach before it is sent for storage. It is also responsible for requesting access information and decrypting it when it is received. * Characteristics related to accessing patients' information for research purposes  
The UA has important characteristics that are related to accessing patients' information for research purposes in a privacy-preserving manner. Entering kiosk mode, disabling certain functionalities such as copy-paste functionality, and allowing and prohibiting communication channels are all important characteristics of the UA. These characteristics aim to ensure the privacy of patients' information when used for research purposes. Further details about the characteristics related to using patients' information for research purposes are provided further in this paper.