The Wireless Body Area Network (WBAN) is one of the promising wireless sensor technologies that improve healthcare and constantly exchange health information during authentic time. However, in such a novel system paradigm, a require of a clearly-defined defense line would cause potential users to be concerned about the reveal of their personal information, especially for unauthorized or level malevolent opponents. This article describes the Elliptic Curve Cryptography (ECC) based encryption method for protecting the patient's medicinal information in WBAN. This method uses the symmetric encryption algorithm toward encrypt otherwise decrypt the secret data of secretive patients, and then ECC is the key to distributing, updating, and undoing.