Kryptos

(Newser) - Jim Sanborn punched four messages into his curved copper sculpture, which has sat outside CIA headquarters in Langley, Va., since 1990. The first three messages of "Kryptos" were decoded by NSA cryptographers in 1993, then by fans in 1999. The 97-character fourth message, however, has stumped code breakers for...

(Newser) - The CIA is home to many secrets, but perhaps none so tempting as those punched into a sculpture that sits in its courtyard. Erected in 1990, "Kryptos" features four undulating panels of copper that contain four secret puzzles, three of which were solved in 1999. But the fourth continues...