"Berlin" is the highly anticipated clue from artist Jim Sanborn that's meant to help crypto sleuths unlock the cipher to his enigmatic Kryptos sculpture. The clue was revealed Saturday in a New York Times article.

Sanborn gave the newspaper six letters from the remaining 97 letters that have yet to be solved in the sculpture's final passage. The six letters – NYPVTT – are the 64th through 69th letters of the final 97 characters. When deciphered, they read "BERLIN."

It's the first clue Sanborn has revealed in four years, after he corrected a typo in his sculpture in 2006 to keep crypto detectives from being derailed in their search for solutions.

Sanborn told Threat Level last week that he wanted to reveal a clue to mark the 20th anniversary of the sculpture's dedication at CIA headquarters in 1990. He said it would be a "significant clue" and hinted that it would "globalize" the sculpture. Asked if this meant it would take the sculpture off CIA grounds and out of the United States, he conceded it would.

Code detectives were already at work trying to crack the rest of the solution Saturday afternoon following the new clue revelation. Members of a popular Kryptos Yahoo Group were brainstorming during a 90-minute conference call.

"The 'Berlin' clue makes a lot of sense, in historical context of the Berlin Wall coming down that year," says code cracker Elonka Dunin, a game designer who moderates the Yahoo Group and maintains a comprehensive website on Kryptos.

The Berlin Wall came tumbling down in Nov. 1989, almost exactly a year before the dedication of the Kryptos sculpture at CIA headquarters, and would have been on Sanborn's mind. Dunin also points out that three slabs of the Berlin Wall sit at CIA headquarters, a gift from the German government. Although the slabs weren't dedicated as a monument until 1992, two years after Kryptos, Dunin thinks it's possible the CIA had already chosen a spot for them when Sanborn was designing Kryptos and told him about it.

Kryptos is a 12-foot-high, verdigrised copper, granite and wood sculpture inscribed with four encrypted messages. The sculpture's theme is intelligence gathering (Kryptos is Greek for "hidden").

It features a large block of petrified wood standing upright, with a tall copper plate scrolling out of the wood like a sheet of paper. At the sculpture's base is a round pool with fountain pump that sends water in a circular motion around the pool. Carved out of the copper plate are approximately 1,800 letters, some of them forming a table based on an encryption method developed in the 16th century by a Frenchman named Blaise de Vigenere.

Three of the four sections have already been solved. But the fourth – containing the 97 characters – has confounded crypto detectives for 20 years.

The first message, containing a deliberate misspelling, is a poetic phrase that Sanborn composed:

"Between subtle shading and the absence of light lies the nuance of iqlusion."

The second one, also with a misspelling, decrypts to:

"It was totally invisible. How's that possible? They used the earth's magnetic field. x The information was gathered and transmitted undergruund to an unknown location. x Does Langley know about this? They should: it's buried out there somewhere. x Who knows the exact location? Only WW. This was his last message. x Thirty eight degrees fifty seven minutes six point five seconds north, seventy seven degrees eight minutes forty four seconds west. Layer two."

W.W. refers to William Webster, the former director of the CIA.

The third message, with another misspelling, is a take on a passage from the diary of English Egyptologist Howard Carter describing the opening of King Tut’s tomb in Nov. 1922.

"Slowly, desparatly slowly, the remains of passage debris that encumbered the lower part of the doorway was removed. With trembling hands I made a tiny breach in the upper left-hand corner. And then, widening the hole a little, I inserted the candle and peered in. The hot air escaping from the chamber caused the flame to flicker, but presently details of the room within emerged from the mist. x Can you see anything? q"

Sanborn has said in the past that the previous three sections contain clues to solving the final section. The additional clue he spilled this week may help untangle that final section, but even if sleuths decipher the final code, there's an additional message hidden in the sculpture in the form of a riddle. Sanborn has said sleuths would need to be on the CIA grounds to solve it.

"In part of the code that's been deciphered, I refer to an act that took place when I was at the agency and a location that's on the ground of the agency," Sanborn said during a 2005 interview with Wired.com. "So in order to find that place, you have to decipher the piece and then go to the agency and find that place."

The riddle may refer to something Sanborn buried on the CIA grounds at the time he installed the sculpture. Or, Dunin suggests, it may refer to the location of the Berlin Wall monument on the CIA grounds. In section two of Kryptos, which has already been decoded, there are longitude and latitude coordinates mentioned – 38 57 6.5 N, 77 8 44 W. Sanborn has said they refer to "locations of the agency." Dunin notes that the latitude and longitude of the Berlin Wall monument's location – 38 57 2.5 N, 77 8 40 W – differ from the coordinates mentioned in the Kryptos passage by just four seconds in both the latitude and longitude.

She speculates that the CIA might have originally planned to position the Berlin Wall monument at the coordinates Sanborn mentions on Kryptos, or Sanborn may have been using an incorrect U.S. geological map when he created his sculpture and thus got the coordinates wrong.

It wouldn't be the first inadvertent error on Kryptos. In 2006, Sanborn realized the sculpture contained an unintentional error, a missing x that he mistakenly deleted from the end of a line in section two, a section that was already solved.

The x was supposed to signify a period or section-break at the end of a phrase. Sanborn removed it for aesthetic reasons, thinking it wouldn't affect the way the puzzle was deciphered. In fact it did. What sleuths had until then deciphered to say "ID by rows" was actually supposed to say "layer two." The correction hasn't helped anyone solve the rest of the puzzle, however, in the subsequent four years.

In conjunction with the new clue release, Sanborn has launched a website, Kryptos Clue, to provide an automated way for people to contact him with their proposed solutions to the puzzle. Over the years, numerous people who were convinced that they'd solved the final puzzle section have contacted him. One woman even showed up at his secluded home on an island.

Most of the solutions people have offered have been wildly off-base. Sanborn says that with the launch of his new site, anyone who thinks they've solved the last section will have to submit what they believe are the first 10 characters of the final 97 before he will respond.

Photo of Kryptos courtesy CIA

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