Secure Service Function Chain Provisioning for Task Offloading in Device-Edge-Cloud Computing

Service function chain (SFC) enables network service providers to provide low-latency services to end devices, such as computation-intensive task offloading services through SFC in device-edge-cloud (DEC) computing. However, DDoS attacks can render SFC unavailable and impact task offloading in DEC computing. In this paper, we propose a trust-cooperative virtualized network function (VNF) model based on coalition formation for SFC provisioning. The proposed model records coalition formation information as transactions in the blockchain to protect the VNF information from being tampered with by attackers. Coalition formation for SFC provisioning consists of two steps: VNF node identity verification and the decision to join the coalition. To address the issue of unreliability in SFC deployment due to attacks, we propose a cooperative SFC provisioning algorithm based on security-aware coalition formation to identify trustworthy VNFs for SFC. Moreover, to handle the instability of SFC provisioning caused by DDoS attacks, we present an SFC reprovisioning algorithm based on the stochastic evolutionary coalition game with reward machines (SECGRM) under the constraint of VNF service times. Experimental results show that our proposed algorithms effectively combat malicious attacks and significantly reduce cooperative SFC provisioning latency compared with existing leading approaches.