Oldsmobile Alero won't start, security light blinks

2000 Alero, 2.2liter, 120,000. Occasionally the car won't start and the security light begins to blink. Everything locks up. Engine cranks but won't fire. After waiting 10 mintues the security light goes off then the car acts normal and starts. This was happening on an irregular basis, once every 3 months or so, now it is happening more regularly. Thanks