[Shop-talk] Tell me about transponder keys

[Jimmie Mayfield]

On Sun, Mar 17, 2013 at 12:54:14PM -0700, Dave C wrote:
> I just got a 2013 Subaru Forester.  It apparently uses transponder keys.  
> It looks like the days of having a cheap copy cut to keep in my wallet are 
> over.  So what's the deal with transponder keys?  Can Ace Hardware clone 
> them?  What's the deal about only being able to "program" a maximum of four 
> keys for the car (as per the manual)? Can I make an unlimited number of 
> clones?   Why is everything such a PITA these days?    (I feel a rant 
> coming on....)
> 

Over the last 10 years or so, there have been numerous documented hacks
of RFID-based ignition systems.  Some vehicles don't even need a mechanical
key to unlock the steering column.  This means someone can steal your vehicle
without leaving any damage (which, I would assume, will lead insurance
companies to deny claims on the basis that there's no evidence that the 
vehicle was actually stolen).

So, instead of a brass backup key in your wallet or hidden under a body panel,
perhaps all you need is a smartphone (or maybe a Raspberry Pi), an RFID
transmitter and an appropriate RFID cracking app...