Hi,
I recently lost one of my 'chipped' keys for my car. The dealer (Ford) wanted £130 to replace the lost key (Plus a fee for cutting the key). Instead I found a local locksmith who was able to "clone" my existing key for £50. When I got the new key, i noticed it has a battery which the original ones do not have. I asked about this, and was told that because it is a "programmable" key, it needs the battery.
This got me wondering, would it be possible to reproduce/recreate the transponder signal from my key using electronics? And how difficult this would be. I assume that this is how the cloned key works, and why it needs the battery. The battery is not there to keep the code, since it can be removed and replaced without losing the code.
I've searched on the net, but not really found any info about reproducing an RFID signal. Any ideas or thoughts would be appreciated.