Portable Wireless Devices (PWDs) and Portable Medical Devices (PMDs) are rapidly becoming an integral part of our lives, and even our bodies. Security issues raise great concerns among customers, manufacturers, regulating bodies and civil rights organizations. Another grave concern of PWDs manufacturers is extending the battery life of these systems by reducing power consumption and computing requirements. For this reason, simple but yet highly secure cryptosystems are absent from present day PWDs. The research presented herein addresses this dilemma by combining the most secure cryptography system available -the onetime pad cipher- with a novel key distribution and authentication scheme. The result is a system with military-grade security and PWD-grade power and processing capabilities.