Author: Andreas Schildbach 2014-03-07 10:23:28
Published on: 2014-03-07T10:23:28+00:00
In an email conversation between Johannes Zweng and an unknown recipient, the topic of NFC (Near Field Communication) payment applications is addressed. Zweng mentions that in current phone implementations, the screen must be on already for NFC to be active and it must be unlocked. However, newer OSes are hoped to allow payment apps on the lock screen similar to music players. Zweng goes on to mention Android 4.4's new host card emulation (HCE) feature where the phone emulates a Smartcard and processes ISO7816-4 APDU commands like a Smartcard would do. He notes that this feature works even when the screen is locked and provides a detailed specification of this feature. Moreover, any app that registers itself for HCE and sets its category to CATEGORY_PAYMENT in the Manifest automatically shows up in Adroid's system settings under "Tap & Pay. "However, he also points out that Category_Payment is credit card-centric and covers only the payer side, questioning if there is an API for "reader emulation" which they would need for apps to support the payee side. Since Android 4.4 market penetration is quite far off, Zweng suggests to focus on the already established NFC payment protocols for now.Additionally, it is recommended by Zweng to keep messages transmitted via NFC to not exceed 1 KB in order for a snappy experience. This raises questions regarding bulky X.509 certificates in payment request messages. Lastly, Zweng notes that Bitcoin Wallet currently does not sign payment requests, so he could not try how it would feel.
Updated on: 2023-06-08T14:19:41.327956+00:00