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Topic: Reading an RF key fob (Read 497 times) previous topic - next topic

Hari2m

Hi,

I recently bought a car and it came with just one key, now ordering a key for this vehicle is going to cost lot of money, approximately 900. I want to create a duplicate key with my with available shells at ebay and want to use the same rfid. I do not want to break the security in my car which is risky. And I do not want to use any deavitivation method or any unit that requires to place a key inside. So i got an idea of using my cell phone a key fob.
 My plan is to keep the rfid at home and use a device to read the rfid using a nodemcu and when ever I want to access the car I will turn the key on, which will talk to my phone using the bluetooth connection and then access my server at my home, which then gets the rfid. I also have plans on storing a list of 30-40 ids in my phone, so thqt I can use them when I do not have internet connection.

Is there a way I can make my node mcu to read the rfid and transmit the same to car from my phone? Please suggest ideas.

wvmarle

Is there a way I can make my node mcu to read the rfid and transmit the same to car from my phone? Please suggest ideas.
Normally (assuming they have a reasonable standard of security) those things should use a challenge/response type of communication. The only way to mimic that is to get the actual security key.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

jnolta

How is it that you plan to transmit the rfid by Bluetooth to your phone? I'm pretty sure that you will spend way more trying to set this up than you would just buying the key, if it was even possible. I admittedly don't know much about how the coded keys actually function, but I'm pretty confident the auto manufacturers have built in enough security to prevent any sort of jury rigged system to go around it. Just buy the key or put up with having only one.

Hari2m

Normally (assuming they have a reasonable standard of security) those things should use a challenge/response type of communication. The only way to mimic that is to get the actual security key.
What fo you mean by the challenge response system? Is it possible to read the hex on the key and mimic the same through software?

wvmarle

Challenge/response authentication

When these keyfobs were new, many cars could be stolen using simple replay attacks, but more modern cars are immune to that. So you really have to know how to respond - it's something like the car sends a code, the fob encrypts this with a pre-shared key and sends it back. Then the car knows whether the fob has the same encryption key, and if so opens the door.

Done properly it's nearly uncrackable.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

Delta_G

+1  There's a reason that they make this almost impossible to do.  Because if it were easy then stealing cars would be a breeze. 

Yes there are ways to build what you want to build. But that kind of criminal knowledge isn't shared out on the regular internet.  If it were the people who make the fobs would patch those security holes.  Basically if you don't already know what you're doing and don't already have the criminal connections to clone key fobs, then it is not something that you're going to get just handed to you just for the asking. 
|| | ||| | || | ||  ~Woodstock

Please do not PM with technical questions or comments.  Keep Arduino stuff out on the boards where it belongs.

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