The deliberation of interloper is to interrupt the communication or to invade the location of sender and receiver. One of the primary concerns of wireless sensor networks is the privacy of sender and receiver. There is always a threat of eavesdropper. The chief objective of this paper is to achieve a high degree of security for both source and sink. Due to an open characteristic of wireless sensor network an adversary can easily detect the location of source or sink by eavesdropping on the sensor nodes. In this paper four protection schemes are discussed that can protect the location of both sink and source. These schemes are forward random walk, bidirectional tree scheme, dynamic bidirectional tree scheme and zigzag bidirectional tree scheme. Also in this paper problems associated with both these scheme are also discussed