problem with security system

I have a 95 cadi eldorado, it will not start and the security system said starting disabled due to theft system (something along those lines) we haven't tried making a new key yet and the fuses are all fine, can anyone please give me any info on what we should do, i would really appreciate it, thank you.

have the dealer check your key if ok my best guess would be your lock cylinder is goin south

Sometimes you can wait 10 minutes and then it will allow you to start.