We have considered a UASN composed of both AUVs and fixed underwater sensor nodes that cooperate towards the same application. Nodes may move as well as dynamically join and leave the system. A node joins the system when its mission starts and leaves when its missions finishes. A node may also be forced to leave when suspected of being compromised. The reference application scenario was a distributed surveillance system. The secure communication suite is composed of two integrated components��a secure routing protocol and a set of cryptographic primitives (cipher, digest, and re-keying)��and aims at protecting confidentiality and integrity of the application and network control messages while taking into account the peculiarities of the underwater acoustic medium.

The paper provides the following novel contributions. First of all, the paper presents a practical and efficient solution to secure communication in UASNs. The proposed suite (i) protects end-to-end confidentiality and integrity; (ii) supports both the one-to-one and one-to-many communication paradigm; (iii) allows secure reconfiguration due to nodes mobility, joining, and leaving. The resulting suite introduces limited communication overhead and negligible energy consumption. We show that these claims are well founded by means of sea trials and simulations based on real data. To the best of our knowledge, this is the first secure communication suite that has been implemented and tested in the field.

Second, by means of experiments and real data, the paper proves that the resulting security suite is indeed suitable for an underwater acoustic networking environment.

We believe that reporting design choices and field performance is valuable in itself because it may allow the research community to orient towards either refinements of the proposed approach or different approaches altogether, however with the long-term objective of achieving operational implementations of secure underwater acoustic networks.The paper is organized as follows. Section 2 discusses related work. Section Carfilzomib 3 and Section 4 describe the system and threat model, respectively. Anacetrapib Section 5 describes the cryptographic suite whereas Section 6 describes the secure routing.

Section 7 presents performance evaluation carried out by means of experiments in the field and simulations with real data. Finally, Section 8 reports our final considerations.2.?Related WorkThe problem of secure underwater acoustic communication is quite a new research field [1,2]. Domingo presents a survey of security issues, and possible countermeasures. Similarly, [6,7] analyze the security and threats of UASN. Dong et al. make a taxonomy of the attacks against a UASN [8].