Abstract:Recently, Delay Tolerant Networks (DTNs) have been intensively researched to overcome unstable communication due to the intermittent link connection in wireless communications. In wireless DTNs, to enable continuous connectivity, data are exchanged through intermediate nodes in the path toward the destination node by store-andforward approach. However, since the participating nodes in the network are not fully trusted, a secure data exchange mechanism in the DTNs would be strongly desirable. In this paper, we propose a secure data exchange system in the wireless DTNs using Attribute-Based Encryption (ABE) to provide two properties: (i) content data can be accessed by only authorized nodes that are dynamically defined by a policy on the attributes while keeping its integrity from alteration during transmission, and (ii) routing messages are encrypted and authenticated such that only the attributebased authorized nodes can exchange the routing messages, where multi-hop routing messages are encrypted and authenticated by the ABE. Our experimental results show the practicality of our system.