The Kryptos sculpture, created by Washington DC artist Jim Sanborn, was installed in the central courtyard of CIA Headquarters in Langley, Virginia, in late 1990. The sculpture included a series of encrypted messages.
In late 1992, in response to a challenge from the Deputy Director of the CIA, Admiral William O. Studeman, Vice Admiral John M. "Mike" McConnell at the NSA put together a team to try and solve the codes on the sculpture.
In 1993, the team sent a memo to the CIA detailing their progress. They had solved the first three parts of the sculpture, but not part 4. This information was internal to the Agencies only, and not made public.
In 1998, a CIA Analyst, David Stein, also solved the first three parts, and wrote a report (again private) to the CIA in 1999 detailing his own journey.
In 1999, a California computer scientist, Jim Gillogly, using his home computer, solved the first three parts. This became international news. When the story broke, the CIA then came forward and announced David Stein's success. The NSA said they'd solved it too, but did not give any details about who or when.
In 2003, I (Elonka), while doing research on Kryptos, located a copy of Stein's report, which I published on my website. I had no success in locating a copy of the NSA report other than reading the 2000 article from the Baltimore Sun.
I made several efforts to locate the NSA's notes on their own progress, but kept being told that the information was classified. It was my opinion that the efforts to solve a recreational cipher weren't a matter of national security, and that the information didn't need to be classified.
In March 2010, I filed a Freedom of Information Act request to the NSA, asking to see "all available information about the team's work, and a copy of the memo that was sent to CIA."
The FOIA request (#61191) was a lengthy process, requiring multiple followups and a promise from me that I would pay fees for "professional/executive level search" ($251.00).
After multiple followups, I received the results of the FOIA request in June 2013, a nice plump manila envelope in my mailbox. :)
So here, for the first time public, are the internal documents from the NSA's efforts in 1992 to solve the codes on Kryptos.