On Securing Underwater Acoustic Networks: A Survey

Underwater acoustic networks (UWANs) are often deployed in unattended and untransparent or even hostile environments and face many security threats, while many applications based on UWANs require secure communication, such as costal defense, submarine communication and harbor security. Peculiar features of UWANs such as very constrained resources pose big challenges in defending UWANs against security threats, and many research results are published to address these issues along with several brief surveys available in the literature. This paper aims to provide a comprehensive survey on UWAN security by first discussing the fundamental of network security in general and the main UWAN security threats faced by the physical layer to the transport layer. Then the paper reviews countermeasure schemes against the typical UWAN security threats, securing UWAN protocols and cryptographic primitives designed for UWANs as well as UWAN security structures that address several security issues systematically. The research of UWAN security is still in an early stage, and the paper discusses several important issues necessarily for further studies at the end.