Abstract: The rise of the digital economy has spawned the rapid development of the platform supply chain, but the ensuing network security issues adversely affect the information sharing of the platform supply chain. Aiming at the two-echelon supply chain composed of a manufacturer and an e-commerce platform, this paper considers hacker attacks in an uncertain network security environment, and constructs four models of sharing and non-sharing information of e-commerce platforms under the two modes of resale and consignment. By solving and analyzing the equilibrium decision and ex ante profit of each subject in the four models, the optimal information sharing strategy of the platform is obtained, and then the influence of hacker attack on the information sharing strategy of the platform supply chain is discussed. The study found that: (a) If the market demand forecast is more optimistic and the amount of customer churn caused by hacker attacks is small, information sharing will raise wholesale prices and retail prices. (b) In the resale mode, hacker attacks will not change the equilibrium information sharing strategy of the platform supply chain, that is, do not share information; in the consignment mode, due to the existence of hacker attacks, the platform changes from unconditionally sharing information to sharing information under the condition of low customer churn caused by hacker attacks. (c) Hacking attacks will weaken the information sharing value of each subject in the supply chain, and the weakening degree of hacking attacks on the information sharing value of manufacturers is always higher than that on the information sharing value of e-commerce platforms. This paper can provide a reference for the formulation of the optimal sharing strategy of platform supply chain information under hacker attack.

Key words: Hacker attack, Information sharing, Platform supply chain, Sales model, Equilibrium decisions