Distributed Denial-of-Service (DDoS) is one of the major threats to the cloud environment. Traditional security schemes cannot be used in cloud because of their low efficiency and multi-tenancy challenges. In this paper, we propose an enhanced packet filtering method called ECBF (Enhanced Content Based Filtering) to detect a DDoS attack.This approach is based onentropy value analysis technique. Simulation results show thatour approach is more efficient with acceptable filtering accuracy, supporting real time filtering specifically required for the cloud. © Research India Publications.