In MANETs, providing the security to the network from the routing attacks like black hole and gray hole is a big challenge. To resolve the above issues, in this paper, the authors implement a Cross Layer based Detection and Authentication technique for Secure multi-path Routing (CLDASR). In the authentication method, when a source wants to send a data packet or a RREQ packet, it generates a hash value also encrypts the hash with the path using the shared symmetric key with the destination. In the black hole or gray hole detection method, every node observes the next hop in current route path.