The Name of the Zodiac Killer: Deciphered!
I present below my solution to the "My Name is" Cipher of the Zodiac Killer.
You can watch the video version or read the research in text form.
A man named Arthur Leigh Allen came under suspicion for these crimes when a former friend, Don Cheney,
told police that he recalled Allen as having described a plan to commit murders and send taunting messages to
the media about the matter and that he would call himself “the Zodiac.”
There was enough circumstantial evidence that Allen was the Zodiac Killer that he was questioned about the
case and search warrants were made on his properties in 1972 and again in 1991. Evidence against him
included, of course, the accusation by his former friend and the fact that he wore a Zodiac watch when brought
in for questioning. In 1991, when shown a collection of photos from driver licenses in a lineup, Zodiac survivor
Mike Mageau picked out the image of Allen and identified Allen as the person who had shot him.
But then, before authorities could bring a case against him, Arthur Leigh Allen died in 1992 of a heart attack.
I was not a codebreaker when I worked for the NSA. I was an Arabic linguist. But while I was at the NSA, I took
a week-long course in general methods of cryptography. Using those skills, I will demonstrate in this video
that the name Arthur Leigh Allen is indeed what lies beneath this encrypted message the Zodiac killer sent
back in 1970.
The Encrypted Messages
On July 31, 1969, the Zodiac Killer sent a letter to a number of San Francisco area newspapers, telling them to
print portions of an encrypted message, or else he would continue his killing spree. His letter to the
newspapers stated that the message would reveal his identity. This message employed a simple substitution
cipher, meaning that symbols and letters stood for other letters. In this particular cipher more than one
symbol could represent a letter. When it was deciphered by a history teacher and his wife, the message
displayed the rantings of a criminal and deranged mind. And, despite his claim that the message would reveal
his identify, the message instead stated “I will not tell you my name.”
On November 8, 1969 he sent a letter which contained an enciphered message of 340 characters which has
never been convincingly deciphered.
I believe that following the relatively easy cracking of his first cipher, the Zodiac began to employ encryption
methods that resulted in an unbreakable code. I am not saying that his method of encryption was brilliant. I’m
saying it may have been unfair. For example, he might have drawn up several substitution ciphers and
randomly encoded letters from his message using more than one of them. The resulting message would be
unbreakable simply because, from a cryptological standpoint, it would be nonsense. Let’s remind ourselves,
the Zodiac killer was by definition criminally insane. So I don’t find it implausible that he would have employed
what amounts to disordered encryption methods.
On April 20, 1970, the Zodiac Killer sent the message in which he seems to taunt investigators with his name.
It’s clear he did not want to be caught or have his identification discovered. As such, he was not going to use a
simple substitution cipher for a message in which he seems to dangle his very name in front of investigators. I
think he found it somehow a thrill to actually publish his name in an encoded form. But I believe he did this
while employing an encryption method that was never going to be decipherable using traditional means.
If, as the considerable circumstantial evidence against him suggests, Arthur Leigh Allen was the Zodiac killer,
then the “My Name is” cipher must be constructed from some form of the words Arthur Leigh Allen as the
base text. I will explore whether I can reverse engineer how that man could have taken his name and produced
this particular cipher.
The Enciphered Name
Let’s start with the enciphered message itself. We immediately notice that it is composed of mostly characters
from the Roman alphabet, but also non-alphabetic characters.
And these two different types of characters appear in an interesting distribution within the message.
We have three alphabetical characters in a row, followed by two non-alphabetic characters. Then an alphabetic
character, followed by a non-alphabetic character. Then, it is very interesting that the sequence I just
described exactly repeats itself—in reverse.
What kind of a message would display such symmetry? One answer would be, a message based on a mirror
image of itself.
Note the following. The common abbreviation of Arthur is Art. The name Art Leigh Allen has thirteen letters,
just like the encrypted name.
Now observe the following. If he wrote out that version of his name forward and backward, it results in three
points at which the letters align. Not every name will automatically have such alignments or symmetry. Note,
for instance, that if you juxtapose the full name Arthur Leigh Allen forward and backward, there are no aligned
letters at all.
What is very interesting is that these three aligned letters of the name Art Leigh Allen coincide with three of
the five non-alphabetic characters in the encrypted name.
There are three alphabetic characters at the beginning and the end of the message. Precisely at the point
where the inverted names have an aligned letter, we have a non-alphabetic character. Working inward, we
again have a non-alphabetic character. And at the center letter, where we again have an alignment, we have a
Even just the similarity in structure between the cipher and the inverted name Art Leigh Allen would be
intriguing. But let’s now examine letter by letter how the name Art Leigh Allen might explain the message
Here’s what I think he could have done. He chooses for the first letter the actual first letter of his name. He
does this through sheer arrogance. He still has no intention to send a message that can reasonably be
deciphered. But he finds some thrill in actually showing authorities the first letter of his first name. For the
second letter, he chooses the plain text letter of the reverse of his name.
The next letter in his cipher is N. I propose that he is now choosing letters using a transpositional cipher, in
other words, he is choosing characters at pre-selected distances from the original letter. Here’s the full
alphabet, adding the three non-alphabetic characters he employs at the end. Perhaps he has chosen N
because N is two characters removed from L in the alphabet. Now the fact is, my proposal that he is using a
transpositional cipher would allow me to explain any letter at all, since I could just claim that the enciphered
letter is some random number of positions from one of the letters in the name, forward or backward. This will
only become a convincing proof if some intriguing pattern were to emerge.
The next symbol is the Zodiac Symbol itself. It corresponds to the first double L. Again, I believe the Zodiac
Killer found some weird joy in sending an encoded version of his name to authorities. But L, appearing three
times in the name Art Leigh Allen, is the most common letter. Perhaps he felt he couldn’t risk encoding it with
a substitution or transpositional cipher at all. And so, he didn’t play fair. In place of that L, he used a non-
The next symbol is another non-alphabetic character. Interestingly, this corresponds to the letters E and A in
the plain text. E and A are the second most common letters in the name Art Leigh Allen, each occurring twice.
So he obscures again a letter that might be a useful clue for decipherment. But it is very significant that this
same non-alphabetic character again encodes the same position where the message reads an A and an E in
position 9. That same symbol also encodes the only other point where the inverted name has an alignment of
letters, the G at position 7. At position 10, where there is the second alignment of the letter L, he uses a
different non-alphabetic character. But I assert it is precisely because he didn’t risk encoding the more
common letters of his name that he has inadvertently made his cipher display the precise symmetrical
structure that we observe in the inverted name itself.
I will now show how the rest of the alphabetic characters in the message can be explained using a
transpositional cipher. Again, at position 3, he chooses N, which is two points onward from the letter L in the
backward version of his name. In position 6 he chooses a K, which is two positions onward from the letter I in
the forward version of his name. In position 8 he chooses M, which is four positions onward from the I in the
backward version of his name. Two plus two equals four. At position 11, he again encodes the L of the forward
version with an N, two positions onward in the transpositional cipher. And notice the choice of the letter to
encode has followed a regular pattern, starting from the backward version and then alternating. And I have
not had to resort to random numbers just to arrive at these letters. The transpositions have been two, two,
four, and two.
I have two letters to go. If I can convincingly explain the final two letters, I believe I will have proven my theory
that Art Leigh Allen is the name that this cipher has somehow encoded.
If we use an alphabet that includes the three non-alphabetic characters, the letter A of the cipher is twelve
positions onward from the R of ART.
And the letter M of the cipher is also exactly twelve positions onward from the A of ART.
What’s the significance of the number 12? There are twelve signs of the Zodiac.
Arthur Leigh Allen remains the prime suspect in the Zodiac Killer case because of an abundance of
circumstantial evidence. I believe I have just demonstrated that the name Art Leigh Allen is also the probable
base text of the enciphered name sent by the Zodiac Killer.
by Keith Massey, PhD
In the late sixties and early 70’s the Zodiac Killer terrorized California with a string of murders and letters
boasting of his crimes sent to the media. In these messages, he called himself “the Zodiac,” and he used the
symbol of the Zodiac watch company as his signature. The Zodiac Killer included encrypted messages in his
letters, only one of which was ever deciphered. And in one such letter, he seems to taunt investigators with
his name, in an encrypted form.