1.   Are you ready for robotic Internet search engines, voice-activated Web surfing and airtight online security?

2.   But airtight security has a cost.

3.   He avoided impersonating the richest person on the list, maybe thinking Bill Gates would have airtight security.

4.   While security of facilities managed by the Ministry of the Nuclear Power Industry is being ensured in a general sense, airtight security is far from a done deal.