My name is… Manto Mokhenea?

Deborah Silva unearthed these articles from May 1970 issues of the Oxnard Press Courier:

A woman claimed to have found the name “Manto Mokhenea” in the Zodiac’s unsolved “My name is” cipher.

The name doesn’t quite fit into the cipher (if you assume it is a substitution cipher like the 408). If you make an adjustment, such as “Monto” instead of “Manto”, then the letter counts are correct, but you have to shuffle the letters to make them fit into the cipher text. As we know, this approach is not useful, since it generates millions of possibilities that you can’t narrow down.

Still, I wonder where she got the name “Manto Mokhenea”. It looks more Hawaiian than Russian to me!

UPDATE: A reader points out: Manto Mokhenea – just looks like the “my name is” cipher backwards

Read Gareth Penn’s “Times 17” Online

(Part 1 | Part 2 | Part 3 | Part 4 | Part 5)

A generous Zodiac researcher loaned me a copy of Gareth Penn’s hard-to-find book Times 17: The Amazing Story of the Zodiac Murders in California and Massachusetts, 1966-1981. Gareth Penn is one of the most prominent and prolific people among the many who have inserted themselves into the folklore surrounding the Zodiac case.

Gareth Penn (Credit: Mike Martin)

In 1987, Penn self-published Times 17, a collection of his sprawling essays, filled with well-written but delusional speculations connecting Berkeley professor Michael O’Hare to the Zodiac killings. Repeatedly dismissed by authorities, Penn’s claims span almost 400 pages. The book is filled with elaborate mathematical ideas which superficially appear rational, but fall apart quickly when examined. Penn’s most abundant trick is to use math to simultaneously generate and disguise random coincidences. First, he sets up basic systems of mathematical operations that create new information from the Zodiac’s correspondences and other facts surrounding the case. Then he plucks out the interesting bits of new information generated by his tricks, and ignores all the other uninteresting coincidences. This confirmation bias approach is shared by many similarly misguided amateur sleuths and codebreakers. Penn’s complicated mathematical procedures create a barrier for most readers, making his claims tedious to analyze and challenge. For an example, see my previous article about Penn’s letters to the popular Scientific American writer Martin Gardner. There you can see why Penn’s “binary Morse” system quickly falls apart: Morse code has a hell of lot of different interpretations when you let the codes run together.

Times 17 also features Penn’s “radian theory“, in which two of Zodiac’s killings form an angle of approximately one radian with Mount Diablo.

Map code and clues in Zodiac’s correspondences

Penn’s radian observation

It’s arguable whether this is by design by Zodiac. At the least, it’s an interesting observation. But throughout Times 17, Penn takes the idea to ridiculous extremes, connecting his mathematical games to angles formed by key words and elements of Zodiac’s correspondences. Penn spreads the interesting observation thinly across a great deal of poor reasoning.

Example of Penn’s application of pseudo-mathematics and angles to Zodiac’s letters

Penn’s bizarre behavior led some to think he might be the Zodiac Killer himself. And like Zodiac, Penn even has his own copycat. Former postal carrier Raymond Grant also self-published his own book filled with “proof” of Zodiac’s identity. His book is filled with many of the same mathematical coincidence generators employed by Penn. For many years, Grant has been arguing that Penn was part of a larger team which included Michael O’Hare, O’Hare’s mother, and Penn’s father. Grant claims he discovered and disrupted the catastrophic “Terminus Event“, the culmination of the group’s “Zodiac Project”. On web sites and online forums, Grant repeatedly tried to share his theories, which were met with strong criticisms. This led to a pattern of Grant authoring many lengthy responses and rebukes, only to be followed by their removal because of his frustration with other Zodiac researchers.

Grant describes discovering the “Terminus Event”

Penn and Grant seem to be intelligent, capable writers. But any serious analysis of their claims will lead you to question their sanity. Or at least their motivations. The study of the irrational crimes of the Zodiac killer has branched into an entire forest of irrational behavior, fertilizing an expanding mythology, like UFO enthusiasts have done by filling in the blanks on mysterious events in the sky.

You can now read the entirety of Times 17 online, if you want to subject yourself to the experience. The book is split into five parts, and can be viewed at the following links:

Times 17 – Part 1 of 5
Times 17 – Part 2 of 5
Times 17 – Part 3 of 5
Times 17 – Part 4 of 5
Times 17 – Part 5 of 5

You can also download the entire 100 megabyte PDF here: times-17-full.pdf. (UPDATE: Thanks to zodiphile, the book is now available in epub and mobi formats for reading on mobile devices). For more of Penn’s writing, read his Ecphorizer articles, or his followup book The Second Power (read it online here). He is also reportedly working on a third book. And, you can still visit Penn online at his blog, where you will only find the occasional bizarre posting of his cryptic puzzles.

Be sure to read Michael J. Martin’s comprehensive and fascinating article which goes into a deep exploration of the Gareth Penn saga. O’Hare himself has also written an article about his experience with Penn. Michael Butterfield has also written a lot of interesting material about both Gareth Penn and Raymond Grant.

Film reviewer Mike D’Angelo once wrote, “I think the [Zodiac] movie erred in selecting author Robert Graysmith as its source and nominal protagonist. Zodiac buffs know well that the true obsessive is a fellow named Gareth Penn.” Have a look at Times 17 and see if you agree.

Swedes crack Zodiac’s map code?

Crypto enthusiast Nick Pelling recently posted this interesting article about two Swedish engineers who developed a theory about the Zodiac’s unsolved 32-character “map code”.

I agree with Nick’s assessment that the theory is ridiculously convoluted, and that it cannot possibly be correct.

The map code is the most difficult of Zodiac’s cryptograms to solve, because only three of its symbols are repeated. With so many unique symbols, numerous solutions can fit into those 32 characters. By itself, a solution to the cryptogram is impossible to validate. But maybe someone can discover some indisputable connection between the map and the code. Keep trying!

2013 Cryptologic History Symposium

I had the pleasure of attending this year’s Cryptologic History Symposium, held on Oct 17 and 18 in Laurel, Maryland. The event is organized every two years by the non-profit foundation that supports the NSA’s National Cryptologic Museum.

Crypto conference schwag

The proceedings were filled with dozens of fascinating talks by noteworthy professionals in the world of cryptology, and I met several interesting and colorful personalities. Here are some highlights.

NSA Deputy Director John C. Inglis kicked off the symposium with his keynote talk, in which he spent a lot of time defending the NSA in light of the numerous unauthorized disclosures by Edward Snowden of the NSA’s secret and controversal surveillance programs.

NSA Deputy Director John C. Inglis

York University professor Craig Bauer told a fascinating tale about famed computer scientist Alan Turing’s work on SIGSALY, a telephone voice scrambling machine developed during World War II. Created before the digital age, the machine was humongous and required carefully protected phonograph disks to store the cryptographic keys consisting of random noise.

Craig Bauer giving his talk
SIGSALY, a World War II era speech encryption machine

I spoke with Dr. Bauer and learned that he had included the Zodiac Killer in an interesting talk he gave about famous unsolved codes and ciphers. He’s also working on an upcoming book about this topic. Videos of his talk are available on Youtube:

Part 1:

Part 2:

Click this link to go directly to the Zodiac portion of his talk which starts 12 minutes and 32 seconds into the video. He gives a brief summary of the case, and touches on Gareth Penn’s radian theory and the New York Zodiac copycat killer Heriberto Seda.

Dr. Bauer talks about the Zodiac ciphers

He even gave Heriberto Seda’s cryptogram as an exercise for students of York’s cryptology course.

Can you crack it? Click the image to download the exercises, which include many other interesting ciphers.

At the conference I also met German cryptology author Klaus Schmeh, who writes an interesting German-language blog about various cryptologic mysteries, including the Zodiac ciphers. His book Nicht Zu Knacken (which I wrote about here) has a chapter devoted to the Zodiac ciphers. At the conference, Klaus gave a talk about compiling a list of 32 encrypted books. He showed some examples, ranging from obscure encrypted texts, to more well-known books such as the Voynich Manuscript and Codex Rohonci. He even brought his own hand-made reproduction of the Codex Rohonci as a prop for people to look through.

Video of Klaus’ talk (Part 1):

Video of Klaus’ talk (Part 2):

(The volume is faint, so you’ll need to crank up the volume on your speakers)

Video game developer, cryptology enthusiast and Kryptos expert Elonka Dunin gave a talk about the use of cryptology in the recreational activity of Geocaching. I was surprised to learn that many caches require solving cryptograms and other puzzles before you can learn the location of the caches. She told me that some of the puzzles remain unsolved. You can view them here. Some puzzles are even based on the German Enigma machine.

Geocache cryptogram, courtesy of “Oceana Abel” on DeviantArt.

Dr. Todd Mateer spoke about his cryptanalysis of one of the Beale ciphers. In the original document, James B. Ward’s The Beale Papers, each number in the solved cipher corresponds to a word from the Declaration of Independence. Mateer tried to reconstruct the solution based on the procedure outlined in Ward’s paper. He found that he ran in to trouble due to the numerous variations of the Declaration of Independence that were published in Ward’s day. He also found that there are mistakes in the encipherment, such as duplicate numberings in the version of the DOI in Ward’s paper. How is it that the so-called Beale cipher uses the exact same DOI variant, and the exact same encipherment mistakes, as that of Ward’s decipherment? What are the chances that Beale and Ward made precisely the same mistakes? Mateer’s conclusion is that it’s because the Beale treasure is likely to be a hoax, invented by whomever authored The Beale Papers. Nick Pelling offers the alternate view that the oddities found in the unsolved Beale ciphers reflect a change in the encipherment procedure that causes bits of an encrypted key to show through. Some experiments in this direction might help clarify his idea.

The talk with the most attention-grabbing title was Shame, Sex and Alcohol: Ciphers in the Context of Everyday Practices of Secrecy in Early Modern Times, about encrypted messages left by noteworthy Hungarian historical figures in diaries and correspondences. Here is one of the more colorful excerpts:

Their secrets live on.

The conference was very educational, provoking a thirst for more knowledge and discovery. I don’t want to miss the next one in 2015!

Try, try again

From an upcoming natural language process conference in Seattle comes this paper from UC Berkeley: Decipherment with a Million Random Restarts.

In the paper, Berk-Kirkpatrick and Klein investigate the effectiveness of the “expectation-maximization algorithm” (EM) when it is used to search for solutions to homophonic ciphers. EM explores cipher solutions by using a statistical model of the English language. The paper describes EM getting stuck in local optima, a common problem with these kinds of automatic decipherment algorithms.

To understand the local optima problem, think of a rugged landscape. Your task is to find the largest mountain in the landscape, but you can’t see more than a few yards ahead of you. You walk around, thinking that your best bet is to find the steepest slope and follow it, You get to the top of a hill, thinking you’ve found the tallest mountain, but you’re only standing atop a medium-sized one. How can you find the tallest one?

For the EM algorithm, the answer is to randomly restart the search many times. In the rugged landscape, this translates to randomly and blindly teleporting you somewhere else in the landscape. Eventually, one of the slopes you follow will be the right one.

Zkdecrypto uses a similar approach. At each step, zkdecrypto is making small changes to a solution key, and keeping the changes that make the plain text look a little bit more like English. But it, too, might get stuck on a “small hill”: no matter what changes it makes to the key, the plain text doesn’t improve, and the real one remains beyond its reach until enough restarts are done.

Long story short: If at first you don’t succeed, try, try again.

The paper tries to answer this question: How many restarts are needed to get the right solution? The researchers’ answer is that it depends on the cipher. They looked at the Zodiac’s 408, which turns out to be an easy cipher to solve: Accurate solutions are discovered without more than a hundred random restarts. Then the researchers created their own 340-character cipher, and accurate solutions were found using hundreds of thousands of restarts. They distributed the numerous restarts to the 512 computational cores of a powerful computer graphics card, an approach that is thousands of times faster than running the restarts one at a time in sequence. The increased difficulty in solving the test cipher is attributed to its smaller length, and its larger number of cipher symbols. But even with only a few hundred restarts, more than half of the correct solution to their test cipher is discovered by the program, which is usually enough for a human solver to take over and complete the solution.

The researchers unfortunately repeat the claim that in 2011, Ravi and Knight were the first to crack the 408 using completely automatic methods. Zkdecrypto has been automatically cracking the 408 since 2006.

Finally, Berk-Kirkpatrick and Klein investigated Zodiac’s 340, and mention the possibility that it may not be a homophonic cipher, or even a valid cipher whatsoever. No one even knows its proper reading order. This paper is the first I’ve seen that presents specific evidence to support the argument that the 340 is not a homophonic cipher in a normal reading order. First, the researchers generated 100 more test ciphers that are similar to the 340, and ran their EM algorithm on them with 10,000 random restarts. The result was an average accuracy of 75%, where only two ciphers had less than 51% accuracy. If the real 340 is “normal”, at least part of its message would surely have been revealed by now. When they ran their EM algorithm on the real 340, the best results were still nonsensical. They also found that the search landscape looks much different for the real 340 than it does for their test ciphers, suggesting a strong difference in its construction.

I’m curious about how closely their test ciphers resemble the real 340. Do they contain similar cyclic sequences of homophones? Do they have the weird pivots? What about spelling errors and encipherment errors, which were abundant in the 408? At this point, it seems best to try to guess what Zodiac may have done to make the cipher unsolvable. Then we can generate more test ciphers and automate their solutions. If the real 340 is constructed the same as the test ciphers, then its solution, too, will emerge.

Then again, perhaps we should heed W.C. Fields’ advice:

If at first you don’t succeed, try, try again. Then quit. There’s no point in being a damn fool about it.

BTK word puzzle analysis

Below is contributor Chris Klein’s interesting analysis of the BTK word puzzle. He breaks down the overall puzzle into three smaller puzzles that are suggested by the appearance of clean breaks between major words and the placements of the letter “X”.

Puzzle 1:


  • This puzzle lacks numbers.
  • The locations of the red X‘s suggest puzzle boundaries.

Puzzle 2:


  • The locations of the red X‘s suggest puzzle boundaries.
  • In row 1 column 7 there appears to be a missing number. The letters R, A and D are near this missing number.

Puzzle 3:


  • The locations of the red X‘s suggest puzzle boundaries.
  • In row 11 column 3 there appears to be a missing number. The letters E and R are near this missing number.
  • This puzzle lacks numbers.
  • Very many of this puzzle’s letters are used in words.

I believe that the X‘s are some type of directions for the orientation of the three puzzles.

Notes about each puzzle and final summary.


Each of the puzzles has its own theme with regard to the hidden words within. The theme of each puzzle is as follows:

  • Puzzle 1 ‐ Recon
  • Puzzle 2 ‐ Location
  • Puzzle 3 ‐ Method of operation
  • Puzzle 4 ‐ Identity?

In each puzzle I did the following:

  • Isolate all obvious words by color (yellow).
  • Isolate all sequential and repetitive keystrokes that were not part of an obvious word by color (green).
  • Isolate all “X”s that were non‐sequential by color (red). (I was drawn to isolate the “X”s separately because of the somewhat uniform location of the “X”s throughout the puzzles.
  • Isolate all remaining, apparently random, keystrokes by color(purple).
  • Isolate all numbers by color (blue). (I took some liberty here. In the “original” document that I worked from, the numbers were oddly spaced so that they were near adjacent alphabetic keystrokes. I noticed that for every oddly placed number there was a blank space to its left. I shifted the numbers to the blank spaces to the left. After doing this I noticed there were 2 blank spaces left on the chart. Interestingly the blank space in puzzle 2 is surrounded by the letters R, A, D. The blank space in puzzle 3 is preceded by E, R.
  • In looking at the progression of the 3 puzzles it seems as if the creator became more efficient as he completed each puzzle. Puzzle 1 seems to have a lot of non‐sequential letters that don’t appear to be part of any hidden words whereas puzzle 3 has very few non‐sequential letters that aren’t part of any obvious words. One question I would ask is why the creator didn’t use sequential letters in puzzle 3 in certain places. Maybe there is no reason but there are only (5) non‐ sequential letters that aren’t part of any obvious word and it seems it would have been easy enough to replace those with some other letter.
  • I did not go into the meanings of the different numbers on the chart.
  • Puzzle 1 ‐ Recon

    This puzzle contains no numbers and seems to be pretty uncomplicated.

    Puzzle 2 ‐ Location

    This puzzle seems to be uncomplicated at first but unlike the previous puzzle it contains sets of numbers. It also contains 3 “X”s on or near the same locations as puzzle 1. This puzzle also contains a blank space adjacent to the letters R,A,D.

    Puzzle 3 ‐ Method of operation

    This puzzle appears to be the most detailed of the 3 puzzles. Unlike the previous puzzle there are no numbers but there is a blank space again. This blank space is preceded by the letters E, R. It also contains 3 “X”s on or near the same locations as puzzles 1 and 2.

    Puzzle 4 ‐ Identity?

    Not sure if one would say that all of these puzzles are just parts on 1 main puzzle but I like to consider them separately. That said, I believe the RADER name is announced by the blank space in puzzle 2 and the blank space in puzzle 3. If that were true then I would consider the grouping of puzzles 2&3 to be a separate puzzle and have labeled it as such.
    Anyhow, thats what I have.

Thanks, Chris!

New Scientist

The May 21, 2011 issue of New Scientist ran a feature called “Uncrackable Codes”, which featured MacGregor Campbell’s summaries of eight famous unsolved mysteries: Somerton Man, Beale’s buried treasure, the MIT time-lock puzzle, Kryptos, the Voynich Manuscript, Enigma, Elgar’s unread message, and the Zodiac Killer.

The Zodiac feature doesn’t have any new details, but here are some highlights:

  • “In November 1969, Zodiac sent a code to the local papers that law-enforcers still believe could hold the key to solving the case.” This seems like wishful thinking. Cracking the 408 didn’t catch the killer. But maybe this wish will come true.
  • FBI crypto chief Dan Olson says the 340 “is number one on his unit’s internal ‘top 10’ list of unsolved codes”, and that that he gets about 20 to 30 submissions every year from the public. None have led to breakthroughs.
  • FBI cryptanalysts believe the 340 contains a real message, since the distribution of characters in the rows is not equal to the distribution of characters in the columns. Olson describes this in more detail in the emails he sent to Tom Voigt back in 2009.
  • In 2009, computer scientist Ryan Garlick led his students in an attempt to use genetic algorithms to crack the cryptograms. The attempt was successful for the 408, but not the 340.
  • Another attempt at San Jose State University also failed to produce a solution for the 340.
  • Garlick thinks to crack the 340, its symbols need to be rearranged somehow. But he says figuring out the rearrangement is very difficult: “You have to happen upon exactly the right thing before any of our software tools would even get close.”

These kinds of “Top Unsolved Codes” lists appear from time to time, and usually only contain the briefest summaries of the mysteries. The MIT time-lock puzzle is one I haven’t seen before. And it was nice to see in the Zodiac feature a summary of academic attempts to crack the codes. How many other places in academia have been working on the dusty old Zodiac ciphers? The ones that I’ve come across include:

All the research seems to be centered on attacking the 340 as if it is a simple substitution cipher. Most papers report succeeding at breaking the 408 and failing with the 340. I’ve yet to see any academic research into the idea of rearranging the 340’s symbols, or exploring its other qualities that might offer clues into how it is truly constructed. This seems to point to falsifying the hypothesis that the 340’s plain text is written in valid English, arranged in a normal direction, and enciphered using straightforward homophonic substitution. My guess is that exploring all the strange variations that are possible would result in tools that are too specific to apply to other “pen and paper” style ciphers. A lot of work for potentially zero reward. Who’s up to the challenge?

Mountain of evidence?

Audrey Cooper, managing editor of the San Francisco Chronicle, recently tweeted this:

The thickness of that stack of papers suggests lengthy and convoluted attempts to justify the claimed solution. It’d be interesting to know what approach the solver took. In the photo, the letter starts by discussing the cycling of variants (also known as homophones) in the 408:

The above cipher variants were, for the most part, made in a cyclic order, deteriorating toward the end of the third part of the message

The letter shows the key, with all the variants (homophones) displayed beneath each plain text letter:

Then there’s a breakdown of the key, showing normal-looking alphabetic cipher symbols first, followed by the symbols that look like backwards letters, and then the symbols that look like shapes and punctuation:

The letter writer points out the interesting fact that “LMN” happens to decode to “THE”.

So far, the letter is off to a reasonable and logical start. I wonder where it leads.

The file of solution claims at the Chronicle must be massive. Reporter Kevin Fagan once told me they still get about two submissions per week. It’d be interesting to look at the file to see all the different approaches people have taken, and to find out how many of them fall into the usual traps, and if any of them supply new and useful ideas.