Sonic Screwdriver

sonicOver the weekend I thought up a project to do in the future. Basically I would like to make a sonic screwdriver that actually unlocks doors.

More specifically, passive RFID card doors. Currently I need to swipe my card to enter my work building, but if I was able to read the signal from the RFID when it has power supplied to it, I could store the signal.

Then I just need to buy a sonic screwdriver toy, build a radio transmitter circuit that will take the stored signal and transmit it.