Allen agreed that widespread vehicle attacks are not likely to happen in the future because there would be little monetary incentive to them and they'd require a great deal of work.
Securing vehicles from wireless hacks has less to do with a firewalls and more to do with recognizing an attack is happening and shutting it down before it can manipulate the car.
"You need to take a layered approach, just like you do in enterprise security," Miller said. "The CAN bus is very simple. The messages on it are very predictable, but when I start sending messages to cause attacks..., those messages stand out very plainly."
Carmakers could easily upgrade software to detect malicious CAN messages and instruct critical vehicle systems, such as brakes or transmission, to ignore them, Miller said.
Sens. Edward Markey (D-Mass.) and Richard Blumenthal (D-Conn.) filed legislation this week that would require the federal government to establish standards to ensure that automakers secure a driver against vehicle cyber attacks.
Among other things, the Security and Privacy in Your Car (SPY Car) Act calls for vehicles to be equipped with technology that can detect, report and stop hacking attempts in real time.
"An intrusion detection system for the car network. It's something we've been advocating for a long time," Miller said. "Yeah, Chrysler fixed this particular remote flaw, but there are problem others. We can't build perfect software. Someone is going to hack into another vehicle head unit someday."
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