His key was developed on the splitting of the alphabet, A through to M and N through to Z, and we can see that the 13 Symbol Cipher begins with an A and ends with an M. So what we will do first is place the alphabet alongside the 13 Symbol Cipher and see if we can find any organization or patterns that exist, using simple mathematics first.
The 340 Cipher was the Zodiac Killer's unsolved masterpiece and being a man with an inflated ego, driven by self publicity, what better way to drop us a hint by placing his name and signing off on the final line of the 340 Cipher. You will notice he places the Zodiac crosshair symbol, followed by what could be interpreted as Zodiac and then an upside down Aries symbol, with a line on the top and a dot to the left. So what we shall do is place the correct spelling of Zodiac alongside this version he placed on the 20th line of the 340 Cipher and use the identical technique we used to create the symmetry on the 13 Symbol Cipher. The alphabetical difference of ZOD produces three zero's, the IAC produces 888. These two incorporated together gives us the three circled 8's found on his next cipher, as though he was carrying them forward. It is also apparent on the 13 Symbol Cipher, that either side of the three circled 8's are the Zodiac crosshair and inverted Aries symbol, identical to the final line of the 340 Cipher. So the author effectively carried five symbols from one cipher to another.
Previously it was shown that the Zodiac crosshair was attributed a value by the Zodiac Killer, using a code directly obtained from the 13 Symbol Cipher. It can be seen here on the left and like the 13 Symbol Cipher it is based on a split alphabet, but what it reveals takes the mathematics of the 13 Symbol Cipher to a whole new level.
Even the name KANE or CANE, heavily attached to the Donna Lass case by detective Harvey Hines produces the numbers 3,1,1,5 in the code ie: 315 in order. Also, if we attribute the gematric value to the letters in the 13 Symbol Cipher it produces 1,5,1,3,1,1,1 and 1, the same three numbers once more. So one can see, either attributing gematric values or numerically counting the alphabetical difference on the 13 Symbol Cipher, only the whole numbers of 3,1 and 5 are ever produced. See 'The Hidden Message in the Pines'.
Since the Zodiac was created using horoscopes it was only fair to consider the 13 Symbol Cipher from the standpoint of Zodiac signs, in that the circled 8's may have been circled for a dual purpose and could be interpreted as three Taurus signs. So in the 'Peek Through the Pines' article we did just that and placed all these values into the gematric code. The crosshair was 315, 3 X TAURUS = 93, ARIES = 22 and the remaining alphabetical letters A,E,N,K,M,N,A,M = 14. The total was 444, exactly half of 888, however both numbers are well known to religion. 888 is the figure that represents Jesus or Christ the Redeemer in Hebraic gematria and 444 represents Jesus in standard English gematria, but no matter which way you interpret the 13 Symbol Cipher, either as three 8's or three Taurus symbols, the end result is religion. 444 was then found in the Button Letter code (see article above), and 888 was found in the 13 Hole Postcard, Halloween Card and Pines Card, bringing us full circle. Even the Bus Bomb Letter overlay he sent us one day after the 340 Cipher, was aligned over his 4 crimes at Lake Herman Road, Blue Rock Springs, Lake Berryessa and Presidio Heights. But more crucially, his first three murders of David Faraday, Betty Lou Jensen and Darlene Ferrin fell over the 8 position on the overlay, giving us 888 once more. SEE HERE.
Just a final thought of mathematical trickery with the number 315, bearing in mind calendar dates, in particular the Julian Calendar introduced by Julius Caesar, two years before his murder. The number 315 in the American format, gives us a date of March 15th, the Ides of March, the date Julius Caesar was murdered in 44 BC.
The Romans did not number days of a month sequentially from the first through the last day. Instead, they counted back from three fixed points of the month: the Nones (5th or 7th, depending on the length of the month), the Ides (13th or 15th), and the Kalends (1st) of the following month. The Ides occurred near the midpoint, on the 13th for most months, but on the 15th for March, May, July, and October. The Ides were supposed to be determined by the full moon, reflecting the lunar origin of the Roman calendar. On the earliest calendar, the Ides of March would have been the first full moon of the new year. Taken from Wikipedia.
The Ides of each month occurred on the 13th and 15th, the numbers 3,1 and 5 once again and strangely the IDES OF MARCH in the gematric code = 5+4+5+6+2+6+1+1+5+3+6 = 44, the exact date of Julius Caesar's murder. But is mathematics the enemy here or quite possibly a bright new dawn.