A method of establishing secure communication between a first mobile computing device and a second mobile computing device includes generating a first self-signed key at the first mobile computing device, pairing the first device with a second device, the pairing including receiving user input of a passcode and after receiving the user input sending the first public key to the second mobile computing device and receiving a second public key from the second mobile computing device, storing the second public key in a database of trusted devices, the database of trusted devices being stored in the first mobile computing device, receiving in the first mobile computing device a list of mobile computing devices connected to a mobile network, matching the list of mobile computing device against the database of trusted devices, and establishing secure communication between the first mobile computing device and the second mobile computing device.