This is a method to find the Key to Kryptos, the sculpture by James Sanborn and which is located at CIA Headquarters. I won't cover the history or details about the sculpture so if you're not familiar with it, you can do some quick research.

Throughout this article, I will refer to the Kryptos sculpture as 'the scroll'. You should also be familiar with the terms 'K1',
'K2', 'K3', and 'K4'.

Step 1: K2 Hidden Message

There is more than one message in each of K1, K2, and K3. I'll refer to the original decoded message as layer one. The other hidden message I'll refer to as the layer two message.

K2 is actually the best example to start with. You have to start with the original, decoded message and put it back into its original, columnar form, or matrix as I prefer to call it. You have to know how many columns wide it is and also at what column it starts. K2 is 8 columns wide and the layer one message starts at column 3. So in the matrix, you should be able to read the layer one message from left to right, top to bottom. The layer two message is read from top to bottom, left to right.

You'll have to infer a few of Sanborn's rules as you work on the layer two message. One is his use of 'X' as a wildcard. You should be familiar with this term if you've ever worked with computers. Anyway, a wildcard can stand for any character. The other rule is the rule of substitution. Any misspelled word is a clue. Whenever you find one, you can substitute the character that will make the spelling correct for the incorrect one. Example: IQLUSION -> tells you you can substitute an 'L' for a 'Q'

So what do the phrases mean? K2 layer one refers to "the earths magnetic field" -> WEST, NORTH, SOUTH, EAST
OCEANS -> whirlpool, constantly in motion. SEA -> reflective pool. TREES -> The petrified tree trunk represents the trees that once stood there. MEADOW -> Part of Sandborn's work included planting grasses and setting rocks to create a meadow.
SEE THE PENNY? -> The question mark is required as part of this phrase. I'll explain later. And of course I'll explain how to find the key.

Step 2: K1 Layer Two Message

This is a real simple one. Again, you read the layer one message from left to right, top to bottom. The layer two message is read from top to bottom, left to right. FIND A QUESTION

This actually refers to K3. I'll cover that in the next step.

Step 3: K3 Layer Two Message

K3 uses the same method but works slightly different. The layer one message is read from top to bottom, left to right. The layer two message is read from left to right, top to bottom. The layer one message refers to the finding of King Tut's tomb. So the first two phrases refer to the ancient beliefs that the pharaohs did not die but simply passed on to another, eternal life. Again, there is a question mark after the last phrase and this is also required. I'll leave it as an exercise for you to find the second and third phrases.

Here you can clearly see the reason for the misspelling of 'DESPARATLY'. You can also see how the layer two message in K1 pertains to K3. We need that 'L' to replace the 'Q' and be able to spell the word 'TITLE'.

Now you know why Sanborn chose 'PALIMPSEST' and 'ABSCISSA' as keywords. Palimpsest is basically reusing a scroll so that there is another hidden message underneath. Abscissa refers to the X axis in geometry. So we use the X axis to find one message and the Y axis to find the other message hidden underneath.

OK, lets go look for that key referenced in K2 layer two.

Step 4: Looking for the Key

Now to look for the key.

This is nothing more than a pattern search. What you need to do is print out the matrix form of K2 and print out K4 beneath it as it appears on the scroll. That is the way I did it. Then start looking for a matching pattern. You'll see that the bottom right part of K2 and the left side of K4 ALMOST match. That's what we are looking for.

Step 5: Hidden in Plain Sight

Sanborn quote: "The most obvious key to the sculpture, nobody has picked up on.".
Sanborn quote: "I used a bit of stego ( steganography) when designing the fourth part of Kryptos."
Me: Look up the definition.

Going back to the K2 layer two message. SEE THE PENNY? THIS KEY HERE IT LIES ON IT
If you've ever done crossword puzzles, you'll know why the question mark is required. A question mark in a crossword puzzle clue infers that you're not looking for a straightforward answer but rather some sort of tricky one. Example: Mental block? Answer: Rubik Cube
Remember that the scroll is made out of copper. Get it ? PENNY -> COPPER So it's saying that the key lies on the scroll.

OK. So how do we use this key? Same way we use a normal house key, or should I say, skeleton key. Insert and turn.

Step 6: How to Use the Key

In order to use the key, we have to insert it into the keyhole and then rotate it 180 degrees. You simulate the insertion by raising it vertically, and the rotation by changing the sequence of the letters. The tab at the end of the key is now pointing to the right. The sequence of letters that I referred to in step 4 as ALMOST matching are now an exact match with those of K2.

It gets more interesting.

Step 7: How the Key Works

You now create a matrix from the combination of K2 and K4 as shown. The yellow highlighted sections are the Key. Notice at the bottom how the 'TWO' and the 'OXO' in both K2 and K4 match up. (See Fig. 2)

There are 259 characters in the K2-K4 matrix. Sanborn tells us that there should be 250. So the three bottom rows are not included when figuring out the K2-K4 solution. Consider the double 'TWO' as the keyhole and the 'VTU' as the part ot the key that stays outside the keyhole and is used to turn the key.

So where does Sanborn mention the number 250? In the Morse code:
T IS YOUR POSITION DIGETAL INTERPRET AT IT

It is easy to see that 'DIGETAL' is a misspelling. Actually in the Morse code, the 'E' is a single dot and Sanborn added an extra space after it. In that space we can add another dot and make it a 'A' or we can add a dash and make it an 'I'.

The first 'T' is a single dash and it also has an extra space after it. We can add another dash and make it an 'M' or add a dot and make it an 'N'. Since this bit or Morse code is right next to the compass rose, it makes sense that Sanborn intended us to make it an 'N' for (N)orth. On the compass rose, the needle that signifies North is pointing to a heading of 250, the digital interpretation of that direction.

An extra space is only included in the two above mentioned places in the Morse code.

Now comes the fun part.

Step 8: K2-K4 Solution

Haven't figured the K2-K4 solution. It's just a matter of doing a word search on the K2-K4 matrix. I'll leave that as a exercise. But here are some hints.

Use the substitution rule. You can replace a 'Q' with an 'L', 'A' with 'E', 'U' with 'O', and an 'X' with any character.

K3 layer two: A CLUE LIES AT MIDDLE SEE PART OF TITLE? Another trick clue. You're not actually looking for 'a title' rather you're looking for the parts that make up the word 'TITLE' or the characters T, I, T, L, and E. In the middle of K3, layer one, you'll find : WIDENING THE HOLE A LITTLE. Notice how the parts of 'TITLE' and 'LITTLE' almost match.

The characters in position 64 through 69 of the K2-K4 solution will spell out 'BERLIN'. That is the clue that Sanborn released last year. (See Fig. 2)

The coordinates in K2 layer one spell out 'RHYMEL' possibly saying that one of the words will rhyme with 'L', such as 'WELL'.
I'll leave that as an exercise also. Need paper and pencil, shouldn't take more than five minutes.

Here's an example of what might appear at the start of the solution:
A LITTLE FORM A RED AND ROUND POLE SOUTH BOLE IN THE AIR
These are just conjectures and there are several possibilities. There are also other clues that I'm sure I'm missing. But it gives you an idea of how to work it.

Step 9: Miscellaneous

Here's some other conjectures and wild theories that may or may not be pertinent.

K1 layer one: BETWEEN SUBTLE SHADING AND THE ABSENCE OF LIGHT LIES THE NUANCE OF IQLUSION
Subtle shading: GRAY
Absence of light: DARK
Definition of nuance: A small change
Changing 'Q' to 'L' = a small change -> ILLUSION
GRAY ILLUSION DARK
Superscript on code side of scroll: YAR On same row on key side: extra 'L'
I'm guessing that Sanborn is telling us to look for a matrix.

LUCIDEEE MEMORYE SOS RQ

LUCODEEE MEMORSE S RQ

---------MORSE
-------------CODE
----------------S

You should be able to read MORSE and CODE from left to right and SOS from top to bottom. Look familiar?

Sanborn has a website where you can submit your answer to the K4 question. Be aware that there is at least one glitch in it. When you click on the box where you enter your email address, a space is automatically inserted before your address. When you hit 'Submit Query', you then get an error message. To avoid this, as soon as you click on that box, hit the backspace to delete that unnecessary space.

Many thanks to those folks who did the hard work, James Gillogly and David Stein.
Thanks to the great websites run by Elonka Dunin, Monet Friedrich, Gary Phillips, and John B. Wilson.