Research On Key Security Technology Of Underwater Wireless Communication Networks

The development and design of low-cost, energy efficiency, high reliability, high securityunderwater wireless communication nestworks(UWCNs) has important theoretical significanceand economic value for the research of marine environmental monitoring and marine resourcesdevelopment. Due to the inherent characteristics of UWCNs and the constraints of underwateracoustic channel, UWCNs are vulnerable to various threats and attacks. Almost all the exisitingresearches on UWCNs are desigened for the purpose of saving energy to prolong the networklifetime. However, the security issues of UWCNs are neglected in these researches. It is importantto study the potential security risks of exisiting technologies and design security system forUWCNs. Therefore, the key security technologies are studied and a security system designed forUWCNs is proposed in this paper. The major contents of this paper can be described as follow:(1) Exisiting researches and the potential security risks are introduced in brief; in addition,exisiting security researches of UWCNs are introduced and studied. The threats and attacks andthe corresponding defending technique are studied. A security system which is suitable for cluster–based UWCNs is designed based on the secure requirement. The security system is composed ofcluster-based security management mechanism, secure clustering scheme based on energy andtrust (SCS-BET), and cluster based secure MAC (CBS-MAC).(2) A cluster-based security management mechanism is proposed for cluster–based UWCNs inthis thesis. The security management mechanism includes: hierarchical hybrid encryptionmechanism, hierarchical hybrid key management mechanism, hierarchical trust managementmechanism, and trust-based malicious node detection mechanism. The hierarchical hybridencryption mechanism is composed of intra-cluster secure communication and inter-cluster securecommunication. The intra-cluster secure communication uses symmetric encryption algorithms,and the inter-cluster secure communication utilizes hybrid encryption mechanism. Thehierarchical hybrid key management mechanism is composed of intra-cluster key managementscheme and intra-cluster key management scheme. The hierarchical trust management mechanismdivides the trust computing to three levels: trust computing at member node, trust computing atcluster-head, and trust computing at sink node. The trust-based malicious node detectionmechanism takes the trust value for detecting maliciou nodes’behaviors, determines the attackedregion and builts routing tree to detect the malicious node.(3) A secure clustering scheme based on energy and trust (SCS-BET) is proposed for cluster–based UWCNs. The secure clustering scheme consists of initialization phase, cluster-head (CH)reselection phase, and topology maintain phase. In the initialization phase, a minimum costclusting scheme is utilized. After the initialization phase, the network topology is fixed. In the CHreselection phase, the trust value and the residual energy are used as evaluation factors. The newCH is assigned by current CH with the highest evaluation values. In the topology maintain phase,the nodes’ status are monitored by CH. Once the network topology changes, correspondingstrategies are used to matain the network topology.(4) A cluster based secure MAC protocol (CBS-MAC) is proposed to solove the security problems in MAC layer. The CBS-MAC protocol is composed of intra-cluster secure MACprotocol and inter-cluster secure MAC protocol.1) The TDMA protocol is used in intra-clustercommunication, and an optimized time slot assignment mechanism is proposed to enhance thechannel utilization. To satisfy the requirment of bursting and high-level data transmission, abursting communication mechanism is proposed. The handshake CDMA protocol is uese ininter-cluster communication to enhance the channel utilization. The protocol utilizes CDMAtechnology to assign different spreading code to each cluster.2) Security mechanism is utilized toenhancethe security of the MAC protocol. The pseudo-random sequences are replaced by chaoticspread-spectrum sequence to improve the security of CDMA system. The symmetric encryptionmechanism is used to ensure the confidentiality of data, and the message authentication code isused to ensure the integrity. The identity–based encryption mechanism is uesed to encrypt thecontrol frames (RTS/CTS) to guarantees the security of establishing links between CHs. The keyagreement phase is combined with the establishment of link to save energy and prolong thenetwork lifetime.