Internet-enabled cars have transformed the lives of drivers. Cars are now mobile offices and home entertainment systems on wheels while being packed with advanced driver assistance systems impossible without connectivity. They can even alert the emergency services while pinpointing their exact position after a breakdown or accident.

But while this level of connectivity brings enormous opportunities, it also adds real threats. At the moment, anyone who hacks into a car’s computer systems has free rein to tamper with its powertrain management and electronic driver aids, and there are enough mischief-makers and fraudsters to make this a major concern. An even bigger worry is the threat of terrorism.

Two years ago at the Consumer Electronics Show in Las Vegas, Sachin Lawande, the president of infotainment with connectivity market leader Harman was warning about the problem.

"The infrastructure of many cars was not designed with networking in mind," he said. "Now that they are connected to the internet their level of exposure is very different. A cyber attacker can take control of critical vehicle functions."

Harman has not only identified the problem, however, but aso developed the solution. At the Frankfurt Show it demonstrated its 5+1 layer security framework, which aims to make cars, and their occupants, invulnerable to cyber attack.

The system offers five tiers of protection, as the name implies, plus over-the-air (OTA) updates so that further developments are automatically added.

Those five tiers provide secure storage for digital certificates, encryption keys and user PINs (Secure Hardware Platform); isolate the various domains (Hypervisor); control who has access to memory and storage (OS Access Control); secure the links between the car’s internal networks and the world outside (Network Protection); and isolate the apps stored within the car (Application Sandboxing).

Harman proudly proclaims it to be even more hacker-proof than the best home internet security system.

"You certainly wouldn’t find layers one and two at home," says Alon Atsmon, Harman’s vice-president for technology strategy. "Even if malware penetrates four layers we still have a fifth, and an outsider cannot touch the CAN-bus which controls the brakes, etc.

Harman has been working on 5+1 for several years, but its development has been speeded up through recent acquisitions like Redbend Software, the global supplier of OTA solutions to mobile carriers.

"It is an open architecture so we could easily include new suppliers," says Atsmon. "OEMs want multiple suppliers. We are implementing it with OEMs already. Partial implementation is there. Comprehensive implementation is in development and you should see it in two years. But it will always be an ongoing process. With OTA updates we can mitigate new threats."