Zonal Architectures Play Key Role In Vehicle Security

The automotive ecosystem is starting to shift toward zonal architectures, making vehicle functionality less dependent on the underlying hardware and allowing more flexibility in what gets processed where.

The impact of that shift is both broad and significant. For carmakers, it could lead to hardware consolidation and more options for failovers in case something goes wrong with any system in the vehicle. Past designs required a dedicated electronic control unit (ECU) for every vehicle function, and offered few options other than redundancy, which is expensive and adds weight. But a zonal approach also changes how security is implemented, and whether that will make a vehicle more or less secure may take years before anyone has conclusive answers.

“In the past, there was no flexibility in the system,” said Robert Schweiger, director of automotive solutions at Cadence. “For each function, there was one hardware box dedicated to the anti-lock braking, or window lifting, for instance. It was dedicated, and there was no flexibility.”

Fig. 1: Functional safety electronics in action. Source: Cadence

Fig. 1: Functional safety electronics in action. Source: Cadence

In a zonal architecture, the central compute unit is surrounded by zonal controllers, which also have a lot of compute power. Certain functions running on the central compute are assigned to run on a particular zonal controller, to perform pre-processing on the zonal controller. That pre-processed data is then passed to a central compute unit to do something else.

“This gives the flexibility to leverage a very powerful hardware architecture for all kinds of things, and allows an additional aspect of consolidating hardware. Not only consolidating functions, but consolidating hardware to more powerful boxes, which leads to cost savings. Cost savings is always a key aspect in automotive that shouldn’t be neglected,” he explained.

Additional scalability in either direction comes by adding additional zonal controllers, or removing some, for entry level cars, while still having the flexibility to assign certain functions to the hardware.

Security concerns
In essence, moving to a zonal architecture means replacing various, loosely-coupled domain-specific data paths with a…