Guohua Shen

Chao Wang, Zhiqiu Huang, Shuren Qi et al.

Copy-move forgery is a manipulation of copying and pasting specific patches from and to an image, with potentially illegal or unethical uses. Recent advances in the forensic methods for copy-move forgery have shown increasing success in detection accuracy and robustness. However, for images with high self-similarity or strong signal corruption, the existing algorithms often exhibit inefficient processes and unreliable results. This is mainly due to the inherent semantic gap between low-level visual representation and high-level semantic concept. In this paper, we present a very first study of trying to mitigate the semantic gap problem in copy-move forgery detection, with spatial pooling of local moment invariants for midlevel image representation. Our detection method expands the traditional works on two aspects: 1) we introduce the bag-of-visual-words model into this field for the first time, may meaning a new perspective of forensic study; 2) we propose a word-to-phrase feature description and matching pipeline, covering the spatial structure and visual saliency information of digital images. Extensive experimental results show the superior performance of our framework over state-of-the-art algorithms in overcoming the related problems caused by the semantic gap.

Yunfei Meng, Zhiqiu Huang, Guohua Shen et al.

Aiming at the privacy preservation of dynamic Web service composition, this paper proposes a SDN-based runtime security enforcement approach for privacy preservation of dynamic Web service composition. The main idea of this approach is that the owner of service composition leverages the security policy model (SPM) to define the access control relationships that service composition must comply with in the application plane, then SPM model is transformed into the low-level security policy model (RSPM) containing the information of SDN data plane, and RSPM model is uploaded into the SDN controller. After uploading, the virtual machine access control algorithm integrated in the SDN controller monitors all of access requests towards service composition at runtime. Only the access requests that meet the definition of RSPM model can be forwarded to the target terminal. Any access requests that do not meet the definition of RSPM model will be automatically blocked by Openflow switches or deleted by SDN controller, Thus, this approach can effectively solve the problems of network-layer illegal accesses, identity theft attacks and service leakages when Web service composition is running. In order to verify the feasibility of this approach, this paper implements an experimental system by using POX controller and Mininet virtual network simulator, and evaluates the effectiveness and performance of this approach by using this system. The final experimental results show that the method is completely effective, and the method can always get the correct calculation results in an acceptable time when the scale of RSPM model is gradually increasing.

Yunfei Meng, Zhiqiu Huang, Guohua Shen et al.

Software defined networking (SDN) has been adopted to enforce the security of large-scale and complex networks because of its programmable, abstract, centralized intelligent control and global and real-time traffic view. However, the current SDN-based security enforcement mechanisms require network managers to fully understand the underlying configurations of network. Facing the increasingly complex and huge SDN networks, we urgently need a novel security policy management mechanism which can be completely transparent to any underlying information. That is it can permit network managers to define upper-level security policies without containing any underlying information of network, and by means of model transformation system, these upper-level security policies can be transformed into their corresponding lower-level policies containing underlying information automatically. Moreover, it should ensure system model updated by the generated lower-level policies can hold all of security properties defined in upper-level policies. Based on these insights, we propose a security policy model transformation and verification approach for SDN in this paper. We first present the formal definition of a security policy model (SPM) which can be used to specify the security policies used in SDN. Then, we propose a model transformation system based on SDN system model and mapping rules, which can enable network managers to convert SPM model into corresponding underlying network configuration policies automatically, i.e., flow table model (FTM). In order to verify SDN system model updated by the generated FTM models can hold the security properties defined in SPM models, we design a security policy verification system based on model checking. Finally, we utilize a comprehensive case to illustrate the feasibility of the proposed approach.

Yunfei Meng, Zhiqiu Huang, Senzhang Wang et al.

To effectively tackle the security threats towards the Internet of things, we propose a SOM-based DDoS defense mechanism using software-defined networking (SDN) in this paper. The main idea of the mechanism is to deploy a SDN-based gateway to protect the device services in the Internet of things. The gateway provides DDoS defense mechanism based on SOM neural network. By means of SOM-based DDoS defense mechanism, the gateway can effectively identify the malicious sensing devices in the IoT, and automatically block those malicious devices after detecting them, so that it can effectively enforce the security and robustness of the system when it is under DDoS attacks. In order to validate the feasibility and effectiveness of the mechanism, we leverage POX controller and Mininet emulator to implement an experimental system, and further implement the aforementioned security enforcement mechanisms with Python. The final experimental results illustrate that the mechanism is truly effective under the different test scenarios.

Yunfei Meng, Zhiqiu Huang, Senzhang Wang et al.

Service-oriented architecture (SOA) system has been widely utilized at many present business areas. However, SOA system is loosely coupled with multiple services and lacks the relevant security protection mechanisms, thus it can easily be attacked by unauthorized access and information theft. The existed access control mechanism can only prevent unauthorized users from accessing the system, but they can not prevent those authorized users (insiders) from attacking the system. To address this problem, we propose a behavior-aware service access control mechanism using security policy monitoring for SOA system. In our mechanism, a monitor program can supervise consumer's behaviors in run time. By means of trustful behavior model (TBM), if finding the consumer's behavior is of misusing, the monitor will deny its request. If finding the consumer's behavior is of malicious, the monitor will early terminate the consumer's access authorizations in this session or add the consumer into the Blacklist, whereby the consumer will not access the system from then on. In order to evaluate the feasibility of proposed mechanism, we implement a prototype system. The final results illustrate that our mechanism can effectively monitor consumer's behaviors and make effective responses when malicious behaviors really occur in run time. Moreover, as increasing the rule's number in TBM continuously, our mechanism can still work well.