I am working for the Company which produces smart lock devices. We want our lock device to support Apple VAS protocol inside. Then our customers just be able to use their smartphones with "Apple Wallet" and our digital key as Wallet Pass to unlock our devices. The problem here is that official spec. on Apple VAS protocol is confidential. I find out that some Companies like ELATEC or IDTech which produces RFID and NFC readers implements Apple VAS in their devices and have so called "Apple’s Value-Added Services (VAS) Certification". But what is an official way to do that? How to get specification of Apple VAS protocol?