From Foster City Patch: "So that's what I started with, said Starliper. I thought, there's no way & that Zodiac is going to be prosaic enough not to mention the U.S. Virgin Islands in this code. This is where it gets even creepier. 3+4+0=7. Right. So you get 7+0=7. 707&707 are the area codes for Vallejo, Napa, and Solano. So I figured, why not start this with Caesar code using 3,4.



Caesar code is a substitution type cipher where an encoder has simply replaced each letter in a message with the letter that is three places further down the alphabet."