nfc means near field communication that means the data transfer will be taking place only when there is a short range b/w the phone and reciever part. one main problem we encounter is about security measures, that can be solved by using secure authentification protocols and adding some user name and all.
i think y can't we use the imei number and imsi number for authetification
by decoding both the numbers and storing in to that app in the phone which will solve the authetification problem .... i request ur help .....