The long-standing cryptographic mystery of the Kryptos sculpture at CIA headquarters has reached a pivotal moment. The fourth and final encrypted passage, which has stumped experts for decades, has reportedly been solved. In a surprising twist, the solution was not discovered through brute-force computing or a cryptanalytic breakthrough, but through historical investigation.

According to reports, two individuals successfully deciphered the elusive code. Their success highlights an unconventional approach to a problem widely considered to be purely in the domain of cryptography. This serves as a potent reminder that information security often involves more than just breaking algorithms; context and external data can provide the ultimate key.

An Unconventional Solution Method

Instead of focusing on the ciphertext itself, the solvers delved into the personal archives of the sculpture’s creator, Jim Sanborn. By meticulously researching his papers stored at the Smithsonian’s Archives of American Art, they uncovered clues that led them directly to the solution. This method underscores the importance of intelligence gathering and research in cracking complex codes, proving that sometimes the key lies outside the encrypted message itself.

Controversy and Legal Complications

The timing of this discovery is described as awkward, as it coincides with Sanborn’s own plans to auction off the solution. The situation is further complicated by the emergence of legal threats, although the basis for these threats remains unclear. Consequently, the two solvers have decided not to publish their solution at this time, leaving the public and the wider cybersecurity community waiting. The final secret of Kryptos, though discovered, remains under wraps for now due to these unfolding circumstances.

Source: https://www.schneier.com/blog/archives/2025/10/part-four-of-the-kryptos-sculpture.html