Cybersecurity Threat Analysis
and Risk Assessment Solution

The amount of electronic systems in cars is constantly increasing due to market demands. With the increasing complexity of new electronic driver assistance and infotainment systems, cars are not only becoming more comfortable and safer, but also more threatened by cyberattacks. The connected car and its components need to be secure throughout its entire lifecycle. To cope with this challenge, it is essential to continuously find out if, where, and how the car is vulnerable, what damage is associated with the threat, and how the impact of the threat will be managed. Otherwise, there are serious risks in the form of financial losses, legal consequences or loss of reputation. For this reason, the cybersecurity regulation ISO 21434 was implemented. It aims to establish a “cybersecurity by design” framework for the entire lifecycle of road vehicles.

One of the key elements of the recently published cybersecurity standard ISO 21434 is the performance of a Threat Analysis and Risk Assessment (TARA), which is the major part of identifying cybersecurity goals. In the best case, the method scales with the status of the development process, so a secure system design is possible right from the start (Security by Design), but it can also be applied for existing systems. This risk assessment method describes different identification and analysis activities throughout the development phases in the lifecycle: from asset identification over threat scenario identification, impact rating, attack path analysis, attack feasibility rating, risk value determination to risk treatment decision.

The purpose of ISO 21434 is to ensure that OEMs and all participants in the supply chain have structured processes in place that support a “Security by Design” process. Especially in the highly dynamic security environment, new vulnerabilities are discovered on a daily basis. These threats must be adequately addressed with updates and new countermeasures to ensure continued security. A model-based approach to safety risk analysis is therefore not only beneficial in the design phase of a vehicle model or component, but crucial and forms the basis for continuous safety risk assessment throughout the vehicle's lifetime.

R 155 has a very far-reaching definition of the period in which the provision of updates for vehicles is mandatory. Security updates need to be provided in all phases of the product lifecycle: during the development and production phase and also throughout the entire operating period, until the car is ultimately no longer active in traffic. To guarantee cybersecurity over this long period of time and to keep your TARAs up to date, it is important to use a flexible solution that adapts to constantly changing conditions, especially when new threats arise. A suitable cybersecurity solution is necessary for this without any doubt.

Spreadsheets are quite often a great support for work, but not really suitable to model TARAs to meet upcoming cybersecurity regulations. We have already explained how a specified solution can help. Nevertheless, here are three compelling arguments against spreadsheets: First, they can not be customized to fulfill ISO 21434 regulation requirements out of the box, thus lacking industry standards. Secondly, spreadsheets don’t run on a model based environment, so the correct referencing of input and changes in the project is not ensured. And last but not least, your TARAs will have to be updated over time and this will bring up problems in the future referencing, particularly when new threats emerge.