Just outside CIA headquarters in Langley, Virginia, lies one of the world’s most famous unsolved cryptographic puzzles—Kryptos. Designed by artist Jim Sanborn in 1990, this intricate copper sculpture contains an encrypted message that has baffled codebreakers, intelligence analysts, and cryptography enthusiasts for over 30 years. While parts of the cipher have been cracked by the NSA and independent researchers, the final section—known as K4—remains a mystery.

This video takes a deep dive into the history, design, and cryptographic techniques behind Kryptos, explaining how previous sections were solved and why the last 97 characters continue to elude even the brightest minds. Is the answer hidden in plain sight? Could you be the one to finally crack the code? Watch to explore the enigma of Kryptos and the secrets it may still hold.