Hello all,

I was quite shocked and happy recently when I heard Z-340 had been broken. Congrats to those involved! This, obviously, lends some weight to the idea that Z-13 may contain a real name.

I decided to process a database of 1219 male names and 88799 surnames against Z-13 using what we have learned from Z-340:

• The text can be transposed using a scytale-like method.[/*:m:1pzv02rm]
• Words can be written backwards. Since the Zodiac only did this on the last section of Z-340, it seems he may have been concerned its short length would make it easy to break (lol)! If this was his mindset, it is not implausible he may have reversed his name.[/*:m:1pzv02rm][/list:u:1pzv02rm]

So, in my program, I allowed for:

• All transpositions from length 1 (normal LTR reading) to 12 (essentially reading backwards from the first character).[/*:m:1pzv02rm]
• The order of the first and last name can be reversed.[/*:m:1pzv02rm]
• The text of either the first or last name, or both, can be reversed.[/*:m:1pzv02rm][/list:u:1pzv02rm]

This gives a total of 8 ways for a name to be enciphered, and a total of 108,245,981 first-name/last-name pairs. I was really surprised to only get 706 solves. Granted, since I only considered pairs whose combined length equals 13 characters, only 18,059,613 pairs were actually considered, but Z-13 is way harder to match a name to than I suspected!

The full list is on pastebin. It is plain-text with 3 columns separated by tabs. I recommend a tab width of 12 characters. The first two columns contain the first and last names, in that order. The final column contains a number, indicating the transposition period the solution occurs at (1 being normal LTR reading), followed by a series of three flags which are either off (a dash) or on (a letter). The letters mean:

• O – The solution requires the order of the names to be swapped (ie: Last name comes first).[/*:m:1pzv02rm]
• F – The solution requires the first name to be lexographically reversed.[/*:m:1pzv02rm]
• L – The solution requires the last name to be lexographically reversed.[/*:m:1pzv02rm][/list:u:1pzv02rm]

I did find a name on the list of someone born in 1940, divorced 1968 and single today, lived all his life in the Palo Alto area, studies animals and is a reasonable fit for the age projections of the Zodiac. The power of Google! Also, this name works on the first 13 of the 18 random characters of Z-408, with three letters of his name appearing as clear-text. In addition, three letters in Z-13 also appear as clear-text. I won’t say who (though I gave you a good hint, there!), since I don’t want to slander a living person on such flimsy ‘proof’, but it’s still gives me the chills to think that the name of the killer could potentially be on this list.

I just thought I’d leave this here in case anyone can make anything of it. My interest in the Zodiac comes and goes, so I didn’t want my efforts to be wasted.

PS: My name does not solve. Phew!

Darren.