1997 Other Nissan Models Starting Problem. Keychip is corupt

Computer problem
1997 Other Nissan Models Engine Size unknown Front Wheel Drive Manual 62000 miles

I have a nissan micra 97 model. Couple of days before my car brakedown and does not start. A mechanic from the breakdown service told me that this is the chip issue which is in the key. It might get corrupted or the sensor doesnot recognise the chip in the key and doesnot allow to startup the engine. What is the cheap solution for it. Or how do I solve it?

thanks,
Sheraz