Now-a-days various In-body Medical Sensors (IBMS) are used to treat and monitor patient’s medical condition continuously, so it has become mandatory to attach a wireless module to these IBMS. This allows the doctors to re-program the IBMS with programming devices wirelessly. This makes it easy for the attackers to take control of the highly protected In-Body Medical Sensor. A normal high computational, more complex and more memory consuming cryptographic code cannot be used in devices like wireless sensor nodes. This IBMS is a tiny wireless device with very limited memory. It must be provided with device compatible security code, to be protected from attacks. Thus, fuzzy vault scheme in Biometric cryptosystem is used in protecting user medical data in real world with a wide range of attacks, but the main demerit is the user medical data is highly visible and the randomly generated chaff points are also easily identified by the attackers who want to hack the data for illegal purposes. A fuzzy vault is chosen because of its infeasibility of reconstructing the polynomial at the receiving end. In order to improve the vault performance, more number of chaff (noise) points is added in a shorter duration. This paper uses a Bio-inspired Flower Pollination Algorithm (FPA) for generating more chaff points in a short duration. Studies show that, using the FPA for the chaff point generation with least input information and can start generating the chaff points in just 0.49 msec. We have presented the simulation result for the proposed fast chaff point generation using Bio- inspired Flower Pollination algorithm in fuzzy vault for WBAN and observed faster chaff point generation and a good acceptable level of ROC.