LOUISVILLE, Ky. -- The secret recipe of Kentucky Fried Chicken is back in Louisville.
The recipe was moved last September to an undisclosed location while KFC's internal security was revamped, local television station WLKY reported.
When dabbling around his kitchen in 1940, it is very unlikely that Col. Harland Sanders thought that one day the recipe he was creating for fried chicken breading would garner this type of security.
The recipe lays out a mix of 11 herbs and spices that coat the chain's Original Recipe chicken, including exact amounts for each ingredient. It is written in pencil and signed by Sanders.
"This recipe has amazing global importance and the reason is that you could maybe put on your hand the number of world, global trade secrets that are housed in a single packet, in a single form," Kentucky Fried Chicken President Roger Eaton said.
Former New York City police detective and security expert Bo Dietl, whose clients include names like Donald Trump, former President George H.W. Bush and the Saudi royal family, was hired to keep the recipe safe.
Dietl admitted he was tempted to take a peek at the recipe.
"The little devil on one side said, 'Open it, look at it,'" he said. "The angel says, 'You're a professional.'"
The iconic recipe is now protected by an array of high-tech security gadgets, including motion detectors and cameras that allow guards to monitor the vault around the clock.
"I know that if our security team recommends Bo, that's good enough for me," Eaton said. "I think part of his expertise is that he's been around the world...he's very experienced and certainly the technology he's brought in I'm very impressed by."
Thick concrete blocks encapsulate the vault, situated near office cubicles, that is connected to a backup generator to keep the security system operating in times of power outages.
"We fortified the ceiling and the floor around here with concrete bricks two feet thick," Dietl said. "We put in motion sensors also CCTV that's hooked up to security downstairs. They have 24/7 armed guys downstairs, so in the amount of 30 seconds you'll have somebody up here. Once in here, you have to have two people with two keys and two different PIN numbers, and that's what you have to have. This safe is bolted down and there is no way anybody can get in here unauthorized without us knowing about it."
Portions of the secret recipe are known by a select few among the executives at Yum! Brands, KFC's parent company, but only two people in the entire organization know it in its entirety.
As to the identities of those individuals, executives refuse to comment.
Distributed by Internet Broadcasting Systems, Inc. The Associated Press contributed to this report. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.