SATS: Secure Data-Forwarding Scheme for Delay-Tolerant Wireless Networks

In this paper, we propose a secure data-forwarding scheme, called SATS, for delay-tolerant wireless networks. SATS uses credits (or micropayment) to stimulate the nodes' cooperation in relaying other nodes' messages and to enforce fairness. SATS also makes use of a trust system to assign a trust value for each node. A node's trust value is high when the node actively forwards others' messages. The highly trusted nodes are preferable in data forwarding to avoid the Black-Hole attackers that drop messages intentionally to degrade the message delivery rate. In this way, SATS can stimulate the nodes' cooperation not only to earn credits but also to maintain high trust values to increase their chances to participate in future data forwarding. Our security evaluation demonstrates that SATS can secure the payment and trust calculation. The performance evaluation demonstrates that SATS can significantly improve the message delivery rate due to avoiding the Black-Hole attackers in message forwarding and stimulating the nodes' cooperation.