2003 Monte Carlo Security Light?

I just bought a 2003 Monte Carlo, and when I got the keys to it they were not chevy keys. They looked like they were cut at Menards or someplace like that. The car starts fine and everything, but I know these cars are supposed to have a chip in the key and these clearly do not. My security light doesnt flash or anything when I lock the doors or when I open them. Its almost like the previous owners bypassed the passkey system or something. Didn't know if there was a fix to this or not, any help would be great. Thanks!