At the heart of CIA headquarters stands an enigmatic sculpture called Kryptos, encoded with a secret message. For over 30 years, it's stumped an entire community of puzzle solvers. Master cryptologist Elonka Dunin refuses to give up on this challenge and today, she may be inching closer and closer to cracking the code.To learn more about how CNN protects listener privacy, visit cnn.com/privacyLearn more about your ad choices. Visit podcastchoices.com/adchoices