Writing security code and develop partially android mobile application

1- I want to design an android application that include the important part for me is the setting interface —> privacy setting interface ( programmed with security code) 2- Type of app: proximity based mobile social network 3- Details of the app: ( communication between adjacent mobile users through Wi-Fi interface, find who are could be friends among nearby strangers through matching operation, the matching performed based on 2 factors to decide whether they could be friends or not. a) interests,and its priority level. b) encounter factor, denotes to the proximity of two users for any desired continuous period of time. Friendship achieved according to the matched profiles using Weighted Euclidean Distance formula to measure the similarity degree between any two users). 3- programming language: java 4- Development environment: android 5- algorithms: private set intersection scheme and partially blind signature algorithm. 6- project objectives: discover potential friends in privacy-preserving fashion. matching should be done securely