WT Week 11

Wireless PAN II - NFC

tldr - NFC operations modes, NFC & QR code mobile payment

Near Field Communication (NFC)

Short range contactless technology which makes use of interacting electromagnetic radio fields

NFC vs RFID

• NFC is a subset of RFID
  • Both uses radio waves for identification purposes
• NFC device works as both a reader and a tag
• NFC only works at very short ranges

Operation Modes

1. Reader-writer mode
   • e.g. Smart phone reads info from an NFC tag embedded in a poster
2. Peer-to-peer mode
   • e.g. 2 smart phones exchanging data
3. Card-emulation mode
   • Mobile payment

Applications

Mobile Payment using NFC

Apple Pay Process

1. Adding card to the phone
   • User enters credit card info. Encrypted info is sent to Apple servers
   • Server sends encrypted message to credit card provider requesting for token and cryptogram
   • Credit card provider forwards encrypted message request to bank
   • Bank issues token and cryptogram back to the phone
   • Token and cryptogram stored in Secure Element (chip inside iPhone)
2. Making a purchase
   • At POS, NFC reader recognises NFC chip in iPhone
   • Secure element sends token and cryptogram to retailer, which is then sent to the credit card network
   • Credit card network determines the authenticity. If it is, the token is sent to the authorising bank
   • Authorising bank decrypts token. It recognises the token, authorises the transaction and sends authorisation back to retailer

Security

• Only works across short distances
• Credit card number never stored on the device
• Credit card number never sent to retailer during payment

Comparison

Mobile Payment using QR Code

Quick Response Code (QR Code)

A 2-dimensional image of black squares that can be decoded by the barcode reader

• Most camera phones can scan and read QR codes

WeChat Pay Process

Method 1

• Open wallet in WeChat
• Select Quick Pay. A QR code and barcode will appear
• Select payment mode (select credit card or WeChat balance)
• Retailer scans QR code to complete the payment

Method 2

• Use WeChat app to scan retailer’s QR code

Security

Method 1

• Payment QR code is generated by the app
• If this QR code is obtained by a third-party, money can be deducted from the owner’s account easily

Method 2

• Payment made by scanning merchant’s QR code
• Phishing QR code can replace genuine QR code
• Scanning this can lead to malware being imported to the device

NFC vs QR Code mobile payment

Advantages of NFC over QR code

• NFC has a very short transmission range, ∴ difficult to hack
• QR code prone to malware attack
• NFC payment only requires a single touch on the reader
• QR code takes longer - open app to scan

Advantages of QR code over NFC

• Not everyone has an NFC-enabled phone
• NFC scanners and tags costly to procure ∴ lower penetration of NFC enabled POS terminals
• QR code more cost effective solution

fin