What Actually Happens When You Tap? The Tech Behind NFC Payments

What Actually Happens When You Tap? The Tech Behind NFC Payments

Near-Field Communication (NFC) is a short-range radio protocol operating at 13.56 MHz within ~4 cm. That limitation is its strength—ensuring security, speed, and accuracy.

When a guest taps their TapNex wristband on a reader:

1. Wake-Up Signal: The reader emits a low-power signal; the tag harvests this energy and responds with a UID.
2. Authentication Begins: An AES-based challenge–response handshake verifies both tag and reader with a session salt.
3. Token Exchange: A one-time-use token tied to the user’s balance is shared—useless if intercepted.
4. Edge Authorization: A local chip checks the token against a hashed valid list—approval is instant, even offline.
5. Cloud Syncing: When online, encrypted logs sync; balances and analytics update in real time.

Why NFC Works Better Than QR or UPI in Crowded Events

Avg transaction time: NFC ~0.3s vs QR/UPI 4–7s. Works offline, with far lower fraud risk and much shorter queues.

Secure by Design

• Physical key storage on the chip prevents extraction.
• AES-256 and TLS 1.3 protect data in transit.
• One-time tokens prevent replay or duplication.
• Role-based access keeps vendor views scoped.

Works Without Internet

Readers handle tens of thousands of offline taps and sync seamlessly later without duplicates.

What Organizers Gain

• Real-time dashboards
• Automatic settlements
• Customizable branding

What Guests Experience

No scan. No wait. No OTP. Just a tap, a green light, and done.