  Generally traffic and the sensor network security have many challenges in the
transmission of data in the network. The existing schemes consider homogeneous
sensor networks which have poor performance and scalability. Due to many-to-one
traffic pattern, sensors may communicate with small portion of its neighbours.
Key management is the critical process in sensor nodes to secure the data. Most
existing schemes establish shared keys for all the sensors no matter whether
they are communicating or not. Hence it leads to large storage overhead.
Another problem in sensor network is compromised node attack and denial of
service attack which occurs because of its wireless nature. Existing multi path
routing algorithms are vulnerable to these attacks. So once an adversary
acquires the routing algorithm, it can compute the same routes known to the
source, and hence endanger all information sent over these routes. If an
adversary performs node compromise attack, they can easily get the encryption/
decryption keys used by that node and hence they can intercept the information
easily. In this paper we are proposing a key management scheme which only
establishes shared keys with their communicating neighbour and a mechanism to
generate randomized multipath routes for secure transmission of data to the
sink. Here we are adopting heterogeneous sensor networks and we are utilizing
elliptic curve cryptography for efficient key management which is more
efficient, scalable, and highly secure and reduces communication overhead. The
routes generated by our mechanism are highly dispersive, energy efficient and
making them quite capable of bypassing the back holes at low energy cost.
