## 3 Methodology and Implementation
### Mobile Application  
The use of a mobile app in a DVI procedure is particularly useful in the event of a disaster or terrorist incident, where postmortem forms are completed. Unlike the anemoterm form, where data can be filled in anywhere with easy access to the network, during such an event there is not always access to the Internet. This means that the data and images collected have to be stored in a different location from the final destination, which is the ID Victim database, and only transferred when the main database is accessed. In addition, it allows for easier collection of information without having to move around the scene with a computer. In addition, the use of a mobile phone enables taking pictures of bodies or parts of bodies using the built-in camera, without the need for an additional camera.  
Another advantage of this solution is the ability to store data in the internal memory of the mobile phone without having to immediately write the data to the main database. Such a solution is not possible with a computer, where data can only be written in real time to an external database. The entire process of using a mobile application in the event of a disaster or terrorist incident is illustrated in the figure below--Figure 14.  
Figure 14: The scheme of operation of the mobile application.  
The mobile application is only used once the scene of a disaster or terrorist attack is secured by the relevant services. This allows the DVI team to enter the scene and collect data. Before using the mobile application, the first step is to log into the system to verify the identity of the person responsible for collecting the data. This means gaining access only to top-down fields depending on the role of the DVI team member concerned. Only after the system is accessed and assigned to an event by the person overseeing the entire process is it possible to proceed to the data collection stage.  
The principle of the mobile application is to create a postmortem form and collect data along with photos at the scene of the incident. Internet access plays a key role in the operation of the application. In the event that this access is restricted, the storage of collected data relating to the postmortem form takes place in the device memory--the database of the Android operating system. This is due to the need to store the collected data in order to synchronize it at a later stage with the main server that collects the data. The next stage is to set up and configure an ad hoc architecture operating with lower throughput parameters and possible signal outages. This will allow data to be collected not only in the phone's memory but also on a temporary server. Once the architecture is set up, it is possible for the application to connect to the local ID Victim server. As a first step, this requires authentication using the details of the person using the mobile application. After authentication, synchronization with the local ID Victim system server takes place. This means transferring the collected data and images stored in the Android system's memory to the LSI. This server systematically attempts to access the WAN. When connected to a WAN, it automatically synchronizes the local database with the main ID Victim server accessible directly from the Internet. If you access the network directly from your phone, there is no need to use the local ID Victim system server. In this case, the collected data are automatically saved on the target server. The final stage is the transfer of the remains to a storage facility and the completion of data on the site and the people involved.  
To address the challenges of data security in disaster victim identification, the ID Victim system integrates robust mechanisms such as WPA2-PSK encryption for secure data transmission and watermarking of photo data to ensure its integrity and prevent unauthorized use.