Since the publication of the EASA certification specification CS-25.1319 in 2020, cyber security of aircraft and aircraft systems (airworthiness security) became mandatory for aircraft certification and must be considered in the aircraft and aircraft systems development even before the detailed design and implementation. For protection of aircraft from cyberattacks by Intentional Unauthorized Electronic Interaction (IUEI), security risk analyses are now embedded in the early phases of aircraft and aircraft systems development and security information has to be provided to subsequent phases. But this also requires, that processes and methods employed at the detailed design and implementation level are compatible to the processes and methods from the level above. For this reason, regulations and corresponding standards are analyzed in this paper to define requirements for a comprehensive and holistic security engineering approach that ensures traceability and consistency along the various development levels in the context of model-based systems, software, and security engineering.

In the MULTICUT problem, given an undirected graph G, a set of pairs of vertices P, and a budget k, the goal is to determine if there is a set S of at most k edges such that for each (s,t)∈P, the graph G−S has no path from s to t. In this article we first study the parameterized complexity of a variant of this problem, where the input graph is edge-weighted with arbitrary weights and the goal is to find a solution of minimum weight. Since weights are arbitrarily large, the weight of the solution is not a good choice for a parameter. The weighted problem is non-trivial even on trees and we study this problem on trees parameterized by structural parameters like the number of leaves and the request degree of every vertex. The studied parameters naturally interpolate the known polynomial time and NP-hardness results for this problem. We also give an FPT algorithm for another variant called WEIGHTED MULTICUT, where given an edge-weighted tree, the goal is to find a solution of size at most k edges that minimizes the weight.