NEW YORK - Has Col. Sanders' nephew inadvertently revealed to the world the secret blend of 11 herbs and spices behind KFC's fried chicken empire?

The company says the recipe published in the Chicago Tribune is not authentic. But that hasn't stopped rampant online speculation that one of the most legendary and closely guarded secrets in the history of fast food has been exposed.

KFC - which is a subsidiary of Yum Brands Inc. - calls its recipe "one of the biggest trade secrets in the world."

The Louisville, Kentucky-based company says that the original recipe from 1940 handwritten by Sanders is locked up in a digital safe that's encased in two feet of concrete and monitored 24 hours a day by a video and motion detection surveillance system.