The CIA's Kryptos sculpture K4 solution sold for $962,500 at auction. The anonymous buyer pledged to keep the 35-year-old cryptographic mystery unsolved.

They swear they haven’t peeked at the closely guarded secret and that they’ll keep the cryptographic competition going.

The CIA's Kryptos sculpture K4 solution sold for $962,500 at auction. The anonymous buyer pledged to keep the 35-year-old cryptographic mystery unsolved.