I’m assuming the stamp in the book is part of the design as opposed to hiding confidential information. That would be ironic. And for a would-be encipherer, just lazy. Thanks again.

My guess is info about the previous owner of the book was printed there and someone decided to protect it.

Yes, actually, if you look hard enough, I’m sure you can make out [insert pet suspect’s name here] beneath the stamp!

But yes, I think you’re quite right, that does seem to make sense. Thanks.

Where did the image come from? Is the book in your possession?

Where did the image come from? Is the book in your possession?

No, not in my possession. One rainy day, with nothing better to do, I trawled through early edition copies of Codebreakers for sale and picked up comments in the description about names, notes, or other markings within the pages. Sellers are very accommodating here. I then asked for a picture, or more details, and all obliged. The most interesting one was reference to "a newspaper article placed within the pages". Naturally, you’re hoping to see "Cipher Slayer" splashed across the top of the article. Unfortunately, the article had been removed and the seller couldn’t even remember anything about it…

Of course, you of all people would be able to point out the astronomical odds against stumbling across the Zodiac’s personal copy of Codebreakers containing his cipher notes in the margins. Assuming he ever had a copy of course. But, hey, it was raining outside

Of course, you of all people would be able to point out the astronomical odds against stumbling across the Zodiac’s personal copy of Codebreakers containing his cipher notes in the margins. Assuming he ever had a copy of course. But, hey, it was raining outside

It was certainly worth a shot!

Not saying Zodiac "didn’t" own that book, but have you ever read it? It’s a really dry, fairly boring history book. I don’t think I learned a single damned thing about code-making from it. Much more useful books existed at that time, to be honest.

I have yet to see a shred of evidence the Zodiac knew anything more than what can be gleaned from the first 40 pages. That skytale/scytale example is even on the cover and the following example is the Zodiac Alphabet. Plus he messed up the Z340 just like the Z408. The Zodiac messes up plenty actually. Clumsy is how I would describe him. He was probably too embarrassed to give the solution to the Z340 because it would have shown him up in front of Dr. DCB Marsh and his colleges in the American Cryptography Association.