Variational method-based distributed optimal guidance laws for multi-attackers’ simultaneous attack

To solve the problem of cooperative encirclement and simultaneous attack of multiple unmanned aerial vehicles, variational method and Hamiltonian optimization are utilized to design an optimal attack trajectory of multiple attackers pursuing a single target that has fixed initial relative state, fixed final relative state and fixed duration of the attack under condition that the acceleration of the target being estimable. When terminal relative state and attack duration are unknown, online calculation algorithm is used to compute a chain of key intermediate points to create the guidance law and ensure successful deliverance of multiple attackers’ simultaneous attack of the target. The only requirement for the multi-attacker communication network is that it contains a directed spanning tree. The guidance laws can function properly as long as one or more attacker can observe the target. The novel guidance laws practicability are verified by simulation results.

Firm investment decisions for information security under a fuzzy environment: a game-theoretic approach

Purpose This paper aims to examine optimal decisions for information security investments for a firm in a fuzzy environment. Under both sequential and simultaneous attack scenarios, optimal investment of firm, optimal efforts of attackers and their economic utilities are determined. Design/methodology/approach Throughout the analysis, a single firm and two attackers for a “firm as a leader” in a sequential game setting and “firm versus attackers” in a simultaneous game setting are considered. While the firm makes investments to secure its information assets, the attackers spend their efforts to launch breaches. Findings It is observed that the firm needs to invest more when it announces its security investment decisions ahead of attacks. In contrast, the firm can invest relatively less when all agents are unaware of each other’s choices in advance. Further, the study reveals that attackers need to exert higher effort when no agent enjoys the privilege of being a leader. Research limitations/implications In a novel approach, inherent system vulnerability of the firm, financial benefit of attackers from the breach and monetary loss suffered by the firm are considered, as fuzzy variables in the well-recognized Gordon – Loeb breach function, with the help of fuzzy expectation operator. Practical implications This study reports that the optimal breach effort exerted by each attacker is proportional to its obtained economic benefit for both sequential and simultaneous attack scenarios. A set of numerical experiments and sensitivity analyzes complement the analytical modeling. Originality/value In a novel approach, inherent system vulnerability of the firm, financial benefit of attackers from the breach and monetary loss suffered by the firm are considered, as fuzzy variables in the well-recognized Gordon – Loeb breach function, with the help of fuzzy expectation operator.

Distributed target-encirclement guidance law for cooperative attack of multiple missiles

The target-encirclement guidance problem for many-to-one missile-target engagement scenario is studied, where the missiles evenly distribute on a target-centered circle during the homing guidance. The proposed distributed target-encirclement guidance law can achieve simultaneous attack of multiple missiles in different line-of-sight directions. Firstly, the decentralization protocols of desired line-of-sight angles are constructed based on the information of neighboring missiles. Secondly, a biased proportional navigation guidance law that can arbitrarily designate the impact angle is cited. The missiles can achieve all-aspect attack on the target in an encirclement manner by combining the biased proportional navigation guidance law and dynamic virtual targets strategy. Thirdly, the consensus protocol of simultaneous attack is designed, which can guarantee that all missiles’ time-to-go estimates achieve consensus asymptotically, and the convergence of the closed-loop system is proved strictly via the Lyapunov stability theory. Finally, numerical simulation results demonstrate the performance and feasibility of the proposed distributed target-encirclement guidance law in different engagement situations.