A Novel Relay Encryption Scheme for Mobile Ad hoc Networks

Security has become a primary concern for providing communication in mobile ad hoc networks(MANET). Compared with a fixed network, a MANET is more vulnerable to attacks such as passive eavesdropping, data tampering and so on, so it is necessary to encrypt transmitted data to ensure its confidentiality. However, in a resource-constrained MANET, the mobile devices have limited capabilities in computation, storage and power, a single source node can not afford the whole encryption task. In this paper, we propose a relay encryption scheme based on threshold secret sharing algorithm, to enhance the data confidentiality, reliability and integrality in MANET. The basic idea is to distribute the whole encryption task to all nodes along the route, every node completes part of the encryption task instead of the single source node encrypting the whole data. In the relay encryption scheme, we divide the whole data into N shares by (T,N) threshold secret sharing algorithm. On the routing path, every node chooses several unencrypted shares and encrypts them separately. With the appropriate value of (T,N) and allocation principle for the number of shares encrypted on each node along the route, the relay encryption scheme can effectively alleviate the burden of the source node and reduce the transmission delay, meanwhile it provides a high level of security, and also improves the reliability of MANET.