I'm new in this arduino world and I would like to know if anybody could help me out building a prototype to switch a relay based on a successfull transaction made through Android and Apple Pay.
Is this possible?... If so, anyone is interested in helping me solve this issue?
I would strongly recommend that you use an approved app or web page for the payments and then use something like a JSON "web service" to present the response which could be accessed via an ESP, though your web service needs to be encrypted and readable by the ESP.
You could make a basic Diffie Hellman key exchange and then MD5 the data and salt it according to the key as a basic 2 way encryption. FYI in real life these numbers generated would be extremely large prime numbers.
Lol sorry for the childish picture but it explains the basic process well.