Both symmetric and asymmetric key algorithms are used to secure a network. Asymmetric key approach involves greater time complexity and hence prone to higher power consumption. Symmetric key cryptography, on the other hand, involves a key exchange phase. In this paper, we propose an authentication technique for new nodes to an ad-hoc network that would also extract the advantages of both symmetric and asymmetric key cryptography while avoiding the adversities. In the proposed collaborative technique, the new node is not only authenticated, but the request-reply messages have been used to generate a secret key at the two ends. The proposed algorithm estimates the distance of a node X from the power loss of a message from X. Both the sender and the receiver separately compute the same secret key based on this distance. The proposed algorithm does not use GPS and identifies location of nodes by distance and direction only.