I think my gen 2 was one button. I wonder why any car still uses a key. But that got me thinking, what would it take to hack the key code?
In the case of cars from VW Group, not much. There was a paper published recently, finally, after two years being withheld due to lawsuits. Basically, most VW, Audi, etc. vehicles made since 2000 all use essentially the same (flawed) encryption mechanism. It turns out, the millions of cars each use one of only a dozen (maybe) unique secret root keys to protect the rolling code and id of the car's assigned keys. If you uncover the root secret from one car, you can have access to at least all other cars of the same model (probably multiple model years and even multiple models) without too much additional work. It's not as simple as hooking up to ODB-II and reading a code, but it's not difficult enough given how many cars are exposed. The VW case was for remote keyless entry, like a "dumb" fob cars have had for decades. Our "smart" key is termed PKES, for "passive keyless entry and start" -- passive in that no button press is required. Ford and other manufacturers have been hacked in the past, including the passive RFID chips embedded in the big-headed keys. (Our keys have a RFID chip, too, as a backup.) I haven't found any specific documented hacks on Prius yet, but Toyota is capable of making the same mistakes as everyone else. Not finding it isn't the same as it not being there. The other thing that has come up recently is thieves using a laptop and the ODB-II port to program a new key (that they brought along) and getting the car to trust it without an original key present. Houston police busted two men for doing exactly this, and have video, so this isn't a theoretical attack. Our cars can be reprogrammed similarly by a dealer or certain locksmiths with the necessary software. They're supposed to check ownership and IDs very carefully, and allegedly it requires communicating with Toyota at some centralized point, but if the feature exists it can be abused or attacked for weaknesses. Despite the above, the mechanical key locks were just as flawed so you're not any worse off.
I simply turn the car off. I use park only if I have to get off the car to open the garage door, or waiting for somebody where I don't risk being rear ended (I guess I would have less damage to the transmission if I get rear ended when not in park, than with Park on and destroying it). I was doing the same on Gen3. I never bothered pressing P before turning off the car. Why bother.
@Gen 2 Tom More reading material, if you're curious: Researchers crack KeeLoq code for car keys (WIRED, 2007) affects Honda, Ford, General Motors, Mercedes Benz and Jaguar Car immobiliser easy to crack, say researchers (BBC, 2015; source technical paper written in 2013) affects Alfa Romeo, Audi, Buick, Cadillac, Chevrolet, Citroën, Daewoo, DAF, Ferrari, Fiat, Holden, Honda, Isuzu, Iveco, Kia, Lancia, Maserati, Opel, Pontiac, Porsche, Seat, Skoda, Ssangyong, Tagaz, Volkswagen, Volvo Keeping your car safe from electronic thieves (New York Times, 2015) The $17 car hacking device does not exist (TheTruthAboutCars.com, 2015) BMW, Audi, and Toyota cars can be unlocked and started with hacked radios (The Telegraph, 2016) Radio attack lets hackers steal 24 different car models (WIRED, 2016) NYT author specifically claims his Toyota Prius was compromised by the theoretical approach described in the article, however the TTAC author questions the conclusion and accuracy of the claim, though the 2016 articles suggest that the attack has been shown to be more practical. All of these attempt to set up a repeater between the car and the fob; the conditions for success will be variable. New wireless hack can unlock 100 million Volkswagens (WIRED, 2016) Thieves go high-tech to steal cars (Wall Street Journal, 2016) Two arrested for stealing Jeeps using laptops (USA Today, 2016) Both about the same set of events recently in Houston, Texas; all seem to be related to Jeep but probably affects more. At this time, they're suspected of using tools and websites intended for dealers to program a new key to the vehicle. Toyota has a similar mechanism on Prius and other vehicles, so that owners no longer need to replace the entire ECU if they happen to lose both master keys -- so we potentially are vulnerable to this. It all depends on what kind of security precautions Toyota takes to secure the dealer-side of things. The dealer network and the people they employ are the weak link in this chain, IMO.
Gen 3 is the same though. If you press power...it automatically turns off and goes into park. No need to hit park first or separately. When I first got my Prius, the old habit of "shifting" into park was with me. But after a while, and some conscious practice I got so I trusted that just hitting power was fine. Now I hardly ever use The Park Button, unless I'm outside on a hot day, and want to "Park" with the engine and air conditioning running...and the brake set. Otherwise it's a seldom used button. Oddly...however it's the one button in which the decal has faded.
