# Secure and Privacy-Protected Bioinformation Implementation in Air Passenger Transport Based on DLT
## 5 Scenario II: iAPIS Based on Corda
### Solution  
This research uses facial information from bioinformation along with the implementation of DLT to improve the iAPIS system. The improved iAPIS process designed in this research is shown in Figure 5. When a passenger checks in for a flight, the camera at the counter records real-time facial information and saves the corresponding information features according to the technical specifications. At this point, the facial information feature data and other identity information listed in the passport form an identity information packet. The airline sends the field containing the identity information and a field indicating the acceptance status to form the PassengerInfoState to the border control agency of the arriving country and proposes a transaction to consume the state. Since the information is not sent in batches, the border control agency can instantly verify and compare the passenger in the database. The border control agency should use a flow to update the acceptance status field based on the results of the inspection. The earliest time window that can be set is before the end of the check-in process to end and return the feedback. Based on the feedback, the airline can deny boarding passes to non-compliant passengers during the check-in process and conduct a secondary inspection during the boarding process. Passengers board the plane via facial recognition during the boarding process, avoiding the need to double-check documents. At the end of the boarding process, the airline sends an updated list to the relevant parties, such as border control agencies, of all passengers who have boarded the aircraft. The agencies can pre-mark the key persons and process them  
\begin{table}
\begin{tabular}{c c} \hline \hline
**APIS Type** & **Properties** \\ \hline \multirow{8}{*}{Non-interactive batch style APIs} & Description: The complete manifest for all passengers needs to be transmitted before departure at the appointed time.Advantages: \\  & - & Batch processing of large amounts of passenger information. \\  & - & Reducing the frequency and system burden of communications. \\  & - & Disadvantages: \\  & - & Limited ability to prevent inadmissible persons from boarding. \\  & - & Description: The API data are transmitted on a per-person basis in real time.Advantages: \\  & - & Real-time data transmission and greater control over the allowance of passenger boarding. \\  & - & More complex to implement. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Comparisons of two types of APIS.  
during border control clearance. All these transactions are recorded in the respective airline and border control agency databases. Transactions belonging to the same flight number and arrival city can be linked in the blockchain to improve traceability.  
The structure of the CorDapp, which shares passenger information between airlines and border control agencies, is shown in Figure 6. Passengers enter facial information during the check-in process, the flow is invoked by the node of the airline to issue a PassengerInfoState, which contains all information of passenger. The issued PassengerInfoState is verified by the corresponding InfoContract to ensure its validity, which is the response of border control agencies. Similar to the principle of the previous scenario, this process only requires validation at the board control agencies and confirmation at the airlines. The list sent by the airlines the second time can be processed in a non-interactive batch style since it is only matched at the agency databases and does not need to receive feedback, and the agencies can have enough time to process the data during the flight.