A Safety-focused Security Risk Assessment of Commercial Aircraft Avionics

An architectural security risk assessment was performed on a commercial aircraft avionics system to identify practical attack scenarios and to qualify their potential safety-impacts and likelihoods. The security risk assessment methodology used was based upon the Airworthiness Security Process Specification (DO-326A), and focused on security scope definition and security risk assessment. This paper describes the methodology used to perform the risk assessment, a description of the selection and relevance of the primary threat conditions, and a summary of the risk level acceptability of the threat conditions.