Electronic Passport Security: What Happens Inside?

Electronic passport security sits at an interesting point between embedded hardware, border control, NFC, biometrics, and public-key cryptography. In a new Elektor TV clip from Elektor Academy Pro’s Post-Quantum Cryptography conference, Nouri Alnahawi discusses what happens when an electronic passport is read, building on an earlier eeNews Europe interview about PACE, PQC, and electronic Machine Readable Travel Documents. For readers following our recent look at post-quantum crypto migration, this is a very concrete example of the problem: a small, standardized, long-lived device that has to keep secrets while talking wirelessly to inspection systems.

Electronic Passport Security: Watch the Clip

An electronic passport, or eMRTD, is not only a paper booklet with a chip tucked inside. The chip stores structured data used to authenticate the document and help verify the holder. That can include the holder’s biographical data and biometric information, while the inspection system performs checks to decide whether the chip data is genuine, whether it has been altered, and whether the chip itself appears to be authentic.
 

In the clip, Nouri Alnahawi walks through the passport-chip side of the story rather than treating an ePassport as a magic black box. The useful bit is the sequence: contactless access, stored data, authentication, and the cryptographic assumptions sitting underneath the whole system.

From NFC Reading to Trust Decisions

The interesting part for engineers is that “reading the passport” is only the beginning. According to ICAO guidance, ePassport validation includes passive authentication, which checks the digital signature to confirm that chip data was written by the issuing state and has not been tampered with. Additional mechanisms can help detect substitution or cloning.

That means a border gate or inspection terminal is doing more than displaying stored data. It is participating in a protocol sequence. It must access the chip, authenticate data, interpret the result, and present a simple decision to a human officer or automated gate. All of that depends on cryptographic assumptions that were reasonable when today’s eMRTD infrastructure was designed.

Electronic Passport Security and PQC Migration

The complication is post-quantum cryptography. Current electronic passport systems rely on classical cryptographic building blocks, while post-quantum migration introduces larger keys, larger signatures, different protocol structures, and new performance constraints. NIST finalized its first PQC standards in 2024, including ML-KEM for key encapsulation and ML-DSA and SLH-DSA for digital signatures, but standards alone do not make a constrained passport chip faster or roomier.

A 2025 IACR Cryptology ePrint paper by Alnahawi and co-authors looked at the practical impact of adding PQC to eMRTD protocols. Its conclusion is not a cartoonish “impossible” or “solved.” Instead, the picture is more engineering-shaped: feasible in some cases, but with real penalties in performance, storage, certificate size, and implementation complexity.

Engineering Around the Passport Chip

This is where the clip becomes useful beyond travel documents. A passport chip is an unusually visible example of a broader embedded security problem. The device is constrained, standardized, deployed globally, expected to last for years, and exposed to hostile environments. That is not so different from secure elements, industrial credentials, vehicle keys, smart meters, medical devices, or long-life IoT nodes.

For embedded designers, electronic passport security is a reminder that cryptographic migration is not just a software-library update. It touches protocol design, certificate chains, memory, timing, interoperability, certification, and the awkward reality that millions of deployed devices cannot be casually replaced. PQC is coming to embedded systems one constrained chip at a time, and passports show just how much work hides behind a quick tap at a smart gate.