Kim K Wedding Security -- Tighter than Bruce Jenner's Face

Wedding crashers BEWARE -- Kim Kardashian's party planning team is taking drastic measures to keep uninvited guests OUT ... with security treating the event "as if it was the White House."

Sources connected to the wedding tell TMZ ... party crashers are being treated as a serious threat ... and not only will security constantly patrol the grounds at the Montecito estate ... but we're told they'll also get support from the sky ... in the form of roaming choppers.

We're told the majority of the wedding festivities will take place either indoors or under tents to thwart the paparazzi -- because the Kardashians don't want the footage to leak out before their special airs on TV.