  In this paper, we present a novel encryption-less algorithm to enhance
security in transmission of data packets across mobile ad hoc networks. The
paper hinges on the paradigm of multipath routing and exploits the properties
of polynomials. The first step in the algorithm is to transform the data such
that it is impossible to obtain any information without possessing the entire
transformed data. The algorithm then uses an intuitively simple idea of a
jigsaw puzzle to break the transformed data into multiple packets where these
packets form the pieces of the puzzle. Then these packets are sent along
disjoint paths to reach the receiver. A secure and efficient mechanism is
provided to convey the information that is necessary for obtaining the original
data at the receiver-end from its fragments in the packets, that is, for
solving the jigsaw puzzle. The algorithm is designed to be secure so that no
intermediate or unintended node can obtain the entire data. An authentication
code is also used to ensure authenticity of every packet.
