Abstract: The present invention relates generally to mechanisms for securing a communication system by using one-time pads. One-time pads may be generated and exchanged in person using proximity based mechanisms including optical communication mechanisms on mobile devices. In particular examples, a quick response (QR) code on one party's mobile device is scanned by the other party's mobile device to securely exchange a randomly-generated symmetric key. The symmetric key is used to encrypt a randomly generated one-time pad transmitted from one party's mobile device to the other party's mobile device. The one-time pad may be shared in encrypted form using proximity based mechanisms including Bluetooth, WiFi, etc.