Timeline 

1988

The CIA commissions artwork for its New Headquarters building, and awards the project to Washington DC artist Jim Sanborn

1990

Sanborn's "Kryptos" sculpture is dedicated at CIA Headquarters

1992

Sanborn creates a related artwork, a 6' tall "Untitled Kryptos Piece" which includes both the text of Kryptos, and Cyrillic-encrypted text regarding KGB operations.  The untitled piece is purchased by DC art collector Gilbert Kinney

Late 1992

In response to a challenge from the Ddputy director of the CIA, Admiral William O. Studeman, the NSA's director, Vice Admiral John M. "Mike" McConnell puts together a four-member team, including Dennis McDaniels and Ken Miller, to solve the puzzles on the sculpture. In December 1992 or January 1993, they sent a memo to the CIA reporting their progress. This is not announced publicly until March 2000.

1993

Sanborn creates an "Encoded Cylinder" piece for a gallery show, which contains a portion of the text from the Cyrillic side of the untitled Kryptos piece.

(date unknown)

Art collector Kinney donates his "untitled Kryptos piece" (also called "Antipodes" or "Covert Balance") to the Hirshhorn Museum in Washington D.C.

1997

The Neuberger Museum commissions a larger version of Antipodes/Kryptos for a gallery show

1997/1998

Sanborn swaps the new 1997 version of Antipodes/Kryptos to the Hirshhorn in return for the smaller 1992 version

1997

The "Encoded Cylinder", renamed "Cyrillic Projector", is installed at the University of North Carolina, Charlotte

1998

CIA Analyst David Stein solves first sections of CIA's Kryptos

early June 1999

Jim Gillogly of California independently solves first three sections of Kryptos with a computer attack.  Kryptos gains international media attention

July 2000

In the process of solving the PhreakNIC v3.0 Code, Elonka Dunin first hears about the Kryptos sculpture.

June 2001

The original 1992 version of Antipodes/Kryptos is sold to a California art collector / philanthropist

May 2002

On the sci.crypt Kryptos discussion group, Italian Ferdinando Stehle independently determines his own mathematical formula for solving part 3 of Kryptos

October 18, 2002

Elonka Dunin, a game developer in St. Louis, takes advantage of an invitation to speak at CIA about Al Qaeda codes, and obtains rubbings and images of Kryptos while she is there

October 24, 2002

Elonka makes her own Kryptos webpage, for posting her rubbings, observations of the raised Y, A, and R letters, and other information about Kryptos.  It becomes a "Kryptos magnet" on the web, and she starts getting international correspondence and questions about the sculpture

January 2003

Ph.D. student Bill Houck of Virginia contacts Elonka about her webpage, and alerts her to the existence of Sanborn's Cyrillic Projector

April 2003

Gary Warzin of Indiana, another Kryptos researcher, contacts Elonka about Kryptos

May 2003

During correspondence with Gary, Elonka comes up with a previously unpublished method of solving Part 3 of Kryptos -- the "pencil and paper" method

May 2003

Gary and Elonka launch a Kryptos discussion group on Yahoogroups.  Dozens of international cryptographers and interested hobbyists join the discussion

May 29, 2003

Jim Gillogly provides his photos of Kryptos from his visit there in 1999.

June 1, 2003

After hearing about the sculpture from Elonka, Randall Bollig takes advantage of a trip through North Carolina to take several photographs of the Cyrillic Projector, which he makes available on the web

June 13, 2003

After weeks of painstaking work, Elonka posts a full transcript of the Cyrillic Projector on her website, based on Randall Bollig's photographs

June 18, 2003

Two other painstaking independent transcripts of the Cyrillic Projector emerge, from Bill Houck of Virginia and Brian Hill of Texas.  They and Elonka's transcript are compared to try and locate any remaining errors. Additional photos of the Projector are obtained from Susan Zimmerman at UNC Charlotte to clarify a few characters that were still raising questions

June 20, 2003

Elonka launches a separate section of her Kryptos site, The Jim Sanborn webpage, to compile a comprehensive list of all of his works.  It becomes the "Sanborn magnet" on the web, and she begins corresponding with art galleries around the country about Sanborn's other pieces

July 9, 2003

(supplemental backdated information) Working independently from Elonka's transcript, a hobbyist in North Carolina, unbeknownst to the Kryptos Group, comes up with a decryption technique for the Cyrillic Projector that results in an output that appears to be Russian text. He can pick out a few words, but is unable to obtain a full translation. He sends a cryptic anonymous letter to Elonka saying he has come up with a solution, but doesn't give enough information about the technique for her to determine whether the letter is from a genuine solver, or is just a prank (she routinely gets emails from mentally ill or hoax-promoting individuals who claim to have "solved" a code, but then when she tries to follow-up, she just finds schizophrenic delusions). Unable to obtain any further information since the letter was sent through her company's anonymous feedback form, she files the letter away.

July 14, 2003

Elonka creates a Flash utility for building vigenere tables such as the ones on  Kryptos and the Cyrillic Projector

August 11, 2003

Sean O'Neil of Australia calculates the "number key" for a column transposition of Kryptos Part III

David Allen Wilson of North Carolina discovers that Sean's number key can be translated to the word "Kryptos"

Elonka applies Sean & David's number key to her own "pencil and paper" method, and finds that the word "Kryptos" can also be used to extract the message in Part III via her system.

Ferdinando Stehle creates an Excel spreadsheet to do Cyrillic vigenere decryption

September 13, 2003

(supplemental) Mike Bales of Michigan independently figures out how to decrypt the different sections of the Cyrillic Projector ciphertext to something that has the statistical properties of Russian (frequency analysis, digraphs, trigraphs, etc.). But, like the solver in July, keeps it to himself since he hasn't yet figured out how to translate the resulting text into English.

September 18, 2003

(supplemental) The July hobbyist, still working in solitude, quietly creates an unmarked webpage describing his solution technique for the Cyrillic Projector. It includes a decryption table and the first two words of Russian plaintext, though he still does not know what the rest of the message says. It also includes one link to Elonka's Cyrillic Projector page, as a resource for additional photos and information

September 19, 2003

While doing a routine daily review of her weblogs, Elonka notices an unusual URL linking to her Cyrillic Projector site -- upon investigating, she finds the hobbyist's unannounced webpage, claiming to have discovered the solution technique for the Cyrillic Projector.  She informs the Kryptos discussion group about it, and then proceeds to confirm the decryption with a modified version of Ferdinando's Excel spreadsheet. Gary Warzin does some digging on the web, based on the unannounced webpage's URL, and determines the hobbyist's name: Frank Corr, and his email address. Elonka writes to the hobbyist, to congratulate him and and ask for more info.  He explains to her that he was the one who sent the anonymous letter in July, but that he still doesn't know what the decrypted message says.

September 20, 2003

Elonka, with the help of her father, consultant Stanley Dunin, and an associate of his, Anatoly K., an engineer from the ex-Soviet Union now living in New Mexico, compiles a translated English plaintext of the Cyrillic Projector Code.  The translation comes out to two sections:  One about secret agents being encouraged to control and manipulate sources of information, and the other a seeming extract from KGB correspondence about Soviet dissident Sakharov's report to the Pugwash Conference being used for an anti-Soviet agenda.

September 20, 2003

Once he learns of the hobbyist's work, Mike Bales steps forward and belatedly informs the Group that he too had come up with a decryption method, but hadn't announced it since he hadn't figured out how to translate the text yet. He posts his decrypted text to the Group library so others can see it.

September 21, 2003

This timeline is created

September 22, 2003

An announcement about the Cyrillic Projector solution is posted to the tech news site, Slashdot, generating thousands of unique visitors to the Kryptos/Projector website within the space of a few hours.

September 23, 2003

Elonka Dunin of Missouri and Anatoly K. of New Mexico solve and translate the remaining cyrillic portions of the Antipodes sculpture. All of the cyrillic on the sculpture is now deciphered.

October 8, 2003

Roger Anderson of Florida points out that all existing transcripts of the Kryptos sculpture were incorrect -- he had noticed an additional "L" at the end of one line on the tableau side.

May 13, 2004

Elonka observes a difference in the text of the Untitled Kryptos Piece, from the text on the CIA version of Kryptos. The Untitled piece also contains two dots in the ciphertext.

October 11, 2005

Monet Friedrich, a member of the Kryptos Group, while experimenting with different methods of shifting text in K2, observes that when using the key BSCISSAA instead of ABSCISSA, it is possible to obtain the text PLAYERTWO at the end of K2 instead of TIDBYROWS. Other group members, such as Paul Kiesel, Mark Siegal, and Thorne Kontos, point out that the correct text might be LAYER TWO, since that lines up better with IDBYROWS. The discovery is discussed, but it is unknown whether or not this is just a random coincidence, similar to several other interesting observations about Kryptos ciphertext and plaintext.

April 19, 2006

Sanborn alerts Elonka that the previously reported plaintext of K2, which ended with IDBYROWS, was not correct. Elonka discusses the situation with the other Kryptos co-moderator Chris "Xenon" Hanson, and together they brainstorm a method for deriving a new set of plaintext, which turns out to be the same LAYERTWO (via a different method) that Monet had observed in October 2005. The correct method involved inserting a ciphertext "s" in the ninth position from the end of K2.

November 20, 2010

Sanborn gives a clue to solving K4. The ciphertext letters NYPVTT decrypt to the plaintext BERLIN.