For decades now automated border control systems, popularly known as eGates, have been used at the border crossing points primarily to speed up clearance process. A significant benefit that the system delivers is that it quickly scans and verifies identities of the travellers entering the borders, thus restricting illegal entry into countries.  This proves effective in preventing terrorism and human trafficking to a large extent. The system is geared to verify the travellers’ identities through biometric parameters without Physical or human intervention.   This ultimately enables organization and management of people traversing the borders more effectively and efficiently.

According to Mordor Intelligence, “the automated border control market is expected to witness a CAGR of 16.25% over the forecast period (2021-2026).  The increasing threat of terrorist attacks and the security standards that have been set by the international authorities that include IATA, ICAO and ACI are among the two most influential drivers sustaining the market.”

Machine Readable Formats Make It Possible

Governments have made significant investments and implemented multiple innovative solutions to strengthen border security control. A machine-readable passport (MRP) is a foundational pillar of cross-border security. MRP is a type of machine-readable travel document (MRTD) that has identification data encoded in optical character recognition (OCR) format.

MRTD is an official travel document, standardized across the globe, issued by a state or organization for international travellers. This OCR-based document makes it easier for automated systems to scan the travel document and its interoperability allows authorities to check visitors against a criminal database to restrict entry.

MRTD contains a standardized format of various identification details of the traveller that includes a picture or a digital image along with mandatory and optional identification elements. The mandatory elements apart from the photograph, are reflected in a two or three-line machine readable zone (MRZ). The MRTD standards are defined in the ICAO 9303 document published by the International Civil Aviation Organization (ICAO) and have been implemented by many countries around the world. MRTD and biometric passports have significantly improved the efficiency of the border control management system.

A widely used MRTD is the machine readable passport (MRP) and each MRP contains various biometric elements to identify the right owner. These elements include retina scans, fingerprints and facial recognition. It also has ICAO-specified features including MRZ and other text attributes that are visible on the first page of the passport.

The key issue with the current border control management system is its centralization.  The systems are controlled by a single entity. As a result, data is not readily shared among different law enforcement agencies. This makes it rather difficult to track down suspected individuals. Also, currently there are no systems available to immediately track, control, blacklist or revoke a suspected passport.

Blockchain for border security controls

Blockchain technology is proposed as an effective solution to mitigate the existing border control management challenges. A list of blacklisted or flagged travel documents can be stored and maintained in a smart contract (one of the features of Blockchain technology). This list can be updated as and when required. Any incremental change made to this list will immediately be visible to all law enforcement agencies and border control points, thus enabling immediate control over the movement of a suspected traveller.

Arguably, traditional mechanisms like PKIs and P2P networks can also be used for tracking down suspected travellers. However, it would fall short of what Blockchain can provide.

Blockchain can simplify the whole system without complex networks and PKI setups, and therefore result in significant cost reduction. Border control management system backed by Blockchain can provide cryptographically guaranteed immutability that helps in auditing and preventing fraudulent activity. A complete database with all travel documents perhaps cannot be effectively maintained or stored in a blockchain network currently due to scalability issues. However, a distributed backend database such as BigChainDB, interplanetary file system (IPFS), or Swarm can be a good substitute.

How to Make It Work?

A hash of the travel document that has the biometric ID of an individual can be stored in a simple smart contract and another hash of the same document can be used to refer to detailed information that is available on the distributed file system such as IPFS. This ensures that when a travel document is blacklisted anywhere on the network, that information will be available immediately with the cryptographic guarantee of its authenticity and integrity throughout the distributed ledger. This functionality can effectively support anti-terrorism activities, thus playing a vital role in the homeland security function of a government.

A smart contract will have a defined array for storing individual details, their respective biometric records and other critical details of identification. These identifying details can be a hash of the MRZ of the passport or travel document that is concatenated with the biometric record derived from the RFID chip. A simple boolean field can be used to identify blacklisted passports. Further detailed biometric verification can be done by traditional systems after the traveller passes all the checks done by the blockchain solution. Eventually, when the decision is finally made regarding the permission for entry status of the traveller, it can then be propagated back to the blockchain network to inform all the stakeholders on the network immediately.

Building blocks of Blockchain-based control system

A high-level approach to building a blockchain-based border control system is illustrated below, for quick understanding:

Here, the passport is initially inspected twice: once with a page scanner and once with an RFID reader. The page scanner reads the data on the page and extracts machine-readable information along with a hash of the biometric data stored in the RFID chip. A live photo and retina scan of the traveller are taken at the time and stored in the database. This information is then passed on to the blockchain network for further checks. A smart contract from the blockchain network will verify the legitimacy of the travel document in two steps. It will first scan through its list of blacklisted passports and then it would request more data from the backend IPFS database to complete the check for flagged passport holders. Note that biometric data such as photo or retina scans are not directly stored on the blockchain network. Instead, only a reference to this data from the backend (IPFS or BigChainDB) is stored in the blockchain.             

Conclusion

To strengthen the border security control system, the gate is programmed to allow access to the traveller only if the travel document data passes two main checks. Firstly, the data presented in the passport should match that of the IPFS/Bigchain DB files. Secondly, it should pass the smart contract logical check. If the data fails to meet one or both checks, access to the gate will be denied and respective authorities will be alerted. After the verification process, the information is propagated throughout the blockchain network and is instantly available to all stakeholders on border control. These stakeholders can be a worldwide consortium of homeland security departments of various nations.

To know more, talk to our Blockchain expert – Dr. Arvind Deenadayalan, Global Head of Blockchain Practice