In recent year, the increasing number of wearable sensors on human can serve for many purposes like emergency care, health care remote monitoring, personal entertainment and communication etc. The healthcare application is used for 24 hours constant monitoring without disturbing day to day activities. The WBAN enables the medical applications to be developed using electronic devices and sensors. The WBAN is created by wearing small sensors on the human body. In this paper we propose a low cost and high quality electro cardiography and diagnostic system for healthcare applications . A major issue is how to preserve security and privacy of patient’s medical healthcare information over wireless communication. The energy consumption and data security are still major challenges in healthcare applications. This paper based on light weight security algorithm. Skipjack is the secret key encryption algorithm which provide the secure communication between sensor node and mobile node. The proposed algorithm protect the patient data against eavesdropping attack.