Credit: Twitter / Nitter (Sept 21, 2022)
Alex Xu said:The diagram below shows the differences. Both approaches are very secure, but the implementations are different. To understand the difference, we break down the process into two flows.
Steps 1 to 3 - Registration of the card
Step 4 to 6 - Tapping the 'Pay' button
- Apple Pay: It doesn’t store any card info. It passes the card info to the bank. Bank returns a token called DAN (device account number). iPhone then stores DAN into a special hardware chip.
- Google Pay: When you register the credit card with Google Pay, the card info is stored in the Google server. Google returns a payment token to the phone.
In the diagram, the red arrow means the credit card info is available on the public network, although it is encrypted
- Apple Pay: For iPhone, the e-commerce server passes the DAN to the bank.
- Google Pay: The e-commerce server passes the payment token to the Google server. Google server looks up the card info and passes it to the bank.
Apple needs to discuss the DAN details with banks. It takes time and effort, but the benefit is that the credit card info is on the public network only once.