A specialized program to be installed in mobile devices to make secure communication with limited group of people. The application shall enables encrypted full duplex speech conversation, encrypted SMS messages and encrypted file exchange. It shall not require any hardware upgrades on the mobile phone itself. For the encryption, 4096 bit RSA public and 256 bit AES private keys shall be used where the AES key is changed for every session/conversation. It shall protect: 1. Voice calls 2. Files Exchange 3.SMS messages. The software shall support following features 1. Encrypted Voice Calls, 2. Encrypted Text Messages, 3. Encrypted Files Exchange,