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CHAOS: An SDN-Based Moving Target Defense System

Published in Security and Communication Networks, 2017


Moving target defense (MTD) has provided a dynamic and proactive network defense to reduce or move the attack surface that is available for exploitation. However, traditional network is difficult to realize dynamic and active security defense effectively and comprehensively. Software-defined networking (SDN) points out a brand-new path for building dynamic and proactive defense system. In this paper, we propose CHAOS, an SDN-based MTD system. Utilizing the programmability and flexibility of SDN, CHAOS obfuscates the attack surface including host mutation obfuscation, ports obfuscation, and obfuscation based on decoy servers, thereby enhancing the unpredictability of the networking environment. We propose the Chaos Tower Obfuscation (CTO) method, which uses the Chaos Tower Structure (CTS) to depict the hierarchy of all the hosts in an intranet and define expected connection and unexpected connection. Moreover, we develop fast CTO algorithms to achieve a different degree of obfuscation for the hosts in each layer. We design and implement CHAOS as an application of SDN controller. Our approach makes it very easy to realize moving target defense in networks. Our experimental results show that a network protected by CHAOS is capable of decreasing the percentage of information disclosure effectively to guarantee the normal flow of traffic.

A Security-Enhanced vTPM 2.0 for Cloud Computing

Published in International Conference on Information and Communications Security, 2017


Virtual Trusted Platform Module is required in cloud due to the scalability and migration of virtual machine. Through allocating a vTPM (Virtual Trusted Platform Module) to a VM (Virtual Machine), users of VM can use the vTPM’s crypto and measurement function, like using the physical TPM. However, current vTPM still faces some key challenges, such as lacking runtime protection for the vTPM keys and code, lacking the mechanism of vTPM keys management, and lacking the support for the new TPM 2.0 specification. To address these limitations, we design vTPM 2.0 system and then propose a runtime protection approach for vTPM 2.0 based on SGX. Furthermore, we present vTPM key distribution and protection mechanism. We have implemented vTPM 2.0 system and the security-enhanced protection mechanism. As far as we know, the vTPM 2.0 system based on KVM and its security-enhanced mechanism are designed and implemented for the first time.