They targeted Apple Pay’s Express Transit Mode, which allows payments without unlocking the iPhone

This kind of claim tends to get exaggerated in social media coverage, so it’s worth separating what’s technically possible in theory from what’s actually practical in real-world conditions.

:mobile_phone: What this is likely referring to

Modern iPhones have an NFC-based feature called Express Mode (Express Transit) within Apple Pay. It allows certain transit payments to work:

  • From a locked iPhone

  • Without Face ID / Touch ID

  • Using a pre-authorized card in a transit context

This is designed for speed at subway gates and buses, not general payments.

A linked Visa card can be part of Apple Pay, but it is still protected by Apple’s tokenization system and Secure Element hardware.


:brain: Why the “attack” is not simple

What’s being described (as highlighted in the Veritasium discussion) involves a scenario like:

  • An attacker tries to trigger NFC communication

  • Makes the phone behave as if it’s interacting with a transit terminal

  • Attempts to trigger a payment flow without unlocking the device

However, in practice:

1. You still need physical proximity

  • NFC range is extremely short (a few centimeters)

  • The attacker must be very close to the device

2. The iPhone uses Secure Element isolation

  • Card numbers are never exposed

  • Transactions use one-time cryptographic tokens

  • Payment authorization is sandboxed from the OS

3. Transit mode is tightly constrained

  • Express Mode only works for pre-approved transit cards / scenarios

  • It does not broadly allow arbitrary Visa payments just because NFC is active


:test_tube: What security researchers usually test

When similar demonstrations appear, they typically rely on:

  • Specialized NFC relay equipment

  • Carefully controlled lab conditions

  • Edge-case configurations (like enabled express transit cards)

Even then, most realistic attacks still require:

  • Close physical access to the device

  • Sometimes the phone being left unattended


:shield: Why real-world theft is still unlikely

For everyday users, several protections remain in place:

  • Payments normally require Face ID / Touch ID

  • Apple Pay uses device-specific encrypted tokens

  • Transactions are limited by time, context, and hardware checks

  • Lost Mode can disable payments immediately


:pushpin: Bottom line

There is no simple “tap a locked iPhone and drain a Visa card” exploit in normal conditions. What exists are highly constrained, proximity-based edge cases involving transit-style NFC behavior, not a general payment bypass that can be easily exploited at scale.

If you want, I can break down how Apple Pay tokenization actually works under the hood—it’s the part that prevents most NFC payment attacks from becoming real-world fraud tools.

What you’re describing is broadly based on a real class of NFC research attacks, but it’s important to separate a controlled academic proof-of-concept from something that can realistically drain someone’s phone in everyday life.

:test_tube: What the research actually is

The work from researchers at the University of Surrey and University of Birmingham (published in 2021-era NFC/payment security research) demonstrates a relay-style attack against contactless payment flows.

In simple terms:

  • An attacker does not “hack” the phone directly

  • They relay NFC communication between:

    • a victim’s phone

    • and a legitimate payment terminal

This is sometimes called a man-in-the-middle relay attack


:mobile_phone: Why the iPhone matters here

The scenario involves Express Transit / Express Mode on an iPhone, where:

  • A small subset of payments can be made while the phone is locked

  • This is designed for speed at transit gates

  • It bypasses Face ID/Touch ID only in that specific transit context

That design choice is what makes the experiment possible in a lab setting.


:credit_card: Where Visa fits in

The demonstration often uses Visa cards because:

  • Visa supports fast contactless authorization flows

  • Some transaction types can be validated quickly in transit-style systems

But importantly:

  • This is not a “Visa encryption break”

  • It is a relay abuse of an already-authorized payment session


:gear: Why it’s not a practical real-world scam

Even though demos (like the Veritasium-style recreation) show dramatic outcomes, real-world use is heavily constrained:

1. Physical constraints

  • NFC range is only a few centimeters

  • Requires very close and sustained proximity to the victim

2. Timing problem

  • Relay attacks must occur during a live transaction window

  • That window is extremely short and inconsistent

3. Device + card conditions

It only works under a narrow set of conditions:

  • Express Transit enabled

  • Compatible card type

  • Specific payment state active on the phone

4. Financial protections exist

  • Card networks (including Visa) provide zero-liability fraud protection

  • Transactions can be disputed and reversed


:brain: Key misunderstanding to avoid

This is not:

  • A remote hack

  • A way to “drain a locked iPhone anytime”

  • A general Apple Pay vulnerability

It is:

  • A niche relay attack on a specific payment mode

  • Demonstrated under controlled conditions

  • Already known to researchers and payment networks


:pushpin: Bottom line

The exploit is real in an academic sense, but it relies on a tight combination of timing, proximity, and configuration that makes large-scale or casual theft extremely unlikely. It highlights how contactless payment systems can be tricked in theory, not that everyday iPhone users are broadly exposed to wallet draining attacks.