With the advancements of Software Defined Networking and Network Function Virtualization technologies, users can access the software-based service function chain (SFC), which is composed of multiple sequential virtual network function (VNF) nodes. Although SFC is more flexible and adaptive in terms of design and deployment, the security risks should not be underestimated. At present, there is a lack of security or risk assessment for SFC, and SFC deployments rarely take their security into account. However, vulnerabilities and risks can cause VNF node failure during operation, which can lead to issues such as disruptions in SFC service and user data leakage. This paper proposes the concept of SFC credibility, which quantifies the authenticity, availability, and reliability of the VNF nodes from both time and space dimensions. Then, a hierarchical credibility evaluation model is built such that VNF nodes can be selected for the user based on their trustworthiness. A credibility-based deployment strategy is further designed for SFC and the corresponding VNF forwarding graph. Furthermore, a comparative study with three existing deployment strategies has shown the advantages of the proposed method. The extensive experimental results demonstrate the improved trust degree and the acceptance rate of SFC with a limited budget.

中文翻译：

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基于信誉的服务功能链部署

随着软件定义网络和网络功能虚拟化技术的发展，用户可以访问由多个顺序虚拟网络功能（VNF）节点组成的基于软件的服务功能链（SFC）。尽管SFC在设计和部署方面更具灵活性和适应性，但不应低估安全风险。当前，SFC缺乏安全性或风险评估，并且SFC部署很少考虑其安全性。但是，漏洞和风险可能会导致VNF节点在操作过程中发生故障，从而可能导致诸如SFC服务中断和用户数据泄漏之类的问题。本文提出了SFC可信度的概念，该概念从时间和空间维度量化了VNF节点的真实性，可用性和可靠性。然后，建立分层的信誉评估模型，以便可以基于用户的可信赖性为其选择VNF节点。为SFC和相应的VNF转发图进一步设计了基于信誉的部署策略。此外，与三种现有部署策略的比较研究表明了该方法的优点。大量的实验结果表明，在预算有限的情况下，证监会的信任度和接受率有所提高。