A Secure and Efficient Cluster-Based Authentication Scheme for Internet of Things(IoTs)

IPv6 over Low PowerWireless Personal Area Network(6LoWPAN)provides IP connectivity to the highly constrained nodes in the Internet of Things(IoTs).6LoWPANallows nodeswith limited battery power and storage capacity to carry IPv6 datagrams over the lossy and error-prone radio links offered by the IEEE 802.15.4 standard,thus acting as an adoption layer between the IPv6 protocol and IEEE 802.15.4 network.The data link layer of IEEE 802.15.4 in 6LoWPAN is based on AES(Advanced Encryption Standard),but the 6LoWPANstandard lacks and has omitted the security and privacy requirements at higher layers.The sensor nodes in 6LoWPANcan join the network without requiring the authentication procedure.Therefore,from security perspectives,6LoWPAN is vulnerable to many attacks such as replay attack,Man-in-the-Middle attack,Impersonation attack,and Modification attack.This paper proposes a secure and efficient cluster-based authentication scheme(CBAS)for highly constrained sensor nodes in 6LoWPAN.In this approach,sensor nodes are organized into a cluster and communicate with the central network through a dedicated sensor node.The main objective of CBAS is to provide efficient and authentic communication among the 6LoWPAN nodes.To ensure the low signaling overhead during the registration,authentication,and handover procedures,we also introduce lightweight and efficient registration,de-registration,initial authentication,and handover procedures,when a sensor node or group of sensor nodes join or leave a cluster.Our security analysis shows that the proposed CBAS approach protects against various security attacks,including Identity Confidentiality attack,Modification attack,Replay attack,Man-in-the-middle attack,and Impersonation attack.Our simulation experiments show that CBAS has reduced the registration delay by 11%,handoff authentication delay by 32%,and signaling cost by 37%compared to the SGMS(Secure GroupMobility Scheme)and LAMS(Light-Wight Authentication&Mobility Scheme).

Low-cost binding update scheme based on pointer forwarding in HMIPv6 network

By introducing a mobility anchor point （MAP）, hierarchical mobile IPv6 （HMIPv6） reduces the binding update signaling cost associated with mobile IPv6, but there still exist deficiencies. For instance, a mobile node （MN） needs to orderly accomplish two binding updates with the MAP and home agent （HA） when the MN performs inter-MAP mobility. This results in a high signaling cost, thus affecting network performance. To reduce the inter-MAP binding update cost of idle MN in HMIPv6, an optimization scheme based on pointer forwarding with a threshold is proposed. The scheme can reduces the binding update cost of idle MN by using the binding update between MAP to replace several home binding updates. The signaling cost difference is derived by analyzing the cost of the basic scheme and the optimization scheme between two successive sessions. Simulation results show that, the optimization scheme can reduce the binding update signaling cost and improve the network performance as long as a suitable threshold is chosen. The discussions on the sensitivity of tele-parameters are also given.

Calling underwater is a costly signal： size-related differences in the call rates of Antarctic leopard seals

It is proposed that where sexually selected vocal communication is an honest signal, the call production rate is predicted to change throughout the breeding season. Male leopard seals call underwater for many hours each day over their three- to four-month breeding season, and it is hypothesized that a decrease in calling rate would be associated with the declining body condition of smaller males. The calling rates of leopard seals were measured （N= 49 recordings） and com- pared between seals of different size classes throughout the breeding season. Male leopard seals produce their calls at more stable rates as they become larger. In this study, larger male leopard seals adopted a strategy of consistent underwater calling throughout the breeding season, whereas there was a breakdown in the calling stereotypy of the smaller males at its height. Toward the end of the breeding season, the smaller seals produced fewer calls in shortened calling bouts, and they took more rest periods. Therefore, underwater calling may represent an honest signal in the leopard seal. For marine mammals that call underwater, the production of repetitive sequences advertises the breath-holding ability of the caller to the listeners, and this ability may be related to male stamina and endurance, thus representing an honest signal that could be widespread in other species.

Single-shot incoherent optical processing of microwave signals： opening the path to low cost high performance analog photonics

Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwave photonics filtering[1–3],arbitrary generation[4–6]and analog to digital conversion[7]。