After 20 years of stumping the world’s best code crackers, “Kryptos” creator Jim Sanborn has revealed part of the infamous 4th panel of his sculpture, which sits in one of the courtyards of CIA Headquarters in Langley, Virginia.  From The New York Times:

So now, after 20 years, Mr. Sanborn is nudging the process along. He has provided The New York Times with the answers to six letters in the sculpture’s final passage. The characters that are the 64th through 69th in the final series on the sculpture read NYPVTT. When deciphered, they read BERLIN.

The first three passages have been solved, but the fourth has proven difficult for a couple of reasons:

One reason the fourth puzzle has proved so difficult is because, with just 97 characters, it is shorter than the others. Longer chunks of text are easier to crack because there is more information to study for patterns.

The messages form the two left-hand panels of the sculpture’s wall of text; the other two panels on the right side provide the key to cracking some of the text. Each is encrypted in a different way from the others.

Sanborn has also launched Kryptos Clue to provide an automated way for people to submit what they think the first 10 characters are.  If you’ve been trying to solve this thing for 20 years, you’ve got 10 characters to get creative with your rage.