I want to make a mobile application where by people can send payments by authorization of finger prints. An email id will be registered and their finger print(unique for everyone) will be stored on our server.Person A and Person B are already registered and have installed the app.A and B deposit some money through our app from their credit card. When a person(Person A) want to send money to other people(person B), person B will ask person A to authorize his/her finger print on person B's mobile.The finger print will be retrieved from our servers and the payment will be made to person B. Person A will open the app (later or at that time) and confirm that yes he/she has authorized his/her finger print for the transaction.If person A has actually done the transaction,no problem.If person A has unknowingly or forcibly and opts that he/she has not authorized his/her finger print,money will be deducted from person B's account. What are the problems/vulnerabilities here,how can it be solved. Any other ways you can suggest to facilitate the transaction