Zodiac Killer Ciphers Wiki - User contributions [en]

Cipher Legitimacy

2012-05-29T14:02:33Z

98.163.23.3:

'''(This article by true crime author [http://www.amazon.com/Michael-D.-Kelleher/e/B000APCA94/ref=ntt_athr_dp_pel_1 Michael Kelleher] is copied from the now defunct site ZodiacKillerCase.com)'''

''Like many other people who follow the Zodiac case, I have long been intrigued and regularly frustrated by the killer's ciphers. However, I simply don't have the kind of brain that can really come to grips with this aspect of the case. My mind seems to go on strike every time I try to approach the ciphers from an objective point of view.''

''Fortunately, there is a small community of exceptionally bright and tenacious individuals who have worked on Zodiac's ciphers for years. Among them is David Oranchak (see the Contributors Section), who has contributed to this site and who clearly has a grasp on this complex part of the Zodiac mystery.''

''Dave has become my cipher-guru. When I need to understand something about the ciphers, Dave always has a ready answer and he is able to put his thoughts into words in a direct and understandable way. So, I went to Dave with a question that has been rattling around in my mind for a long time. Here is the result of that exchange:''

Dave, I have a question, probably a dumb one, because I know so very little about the Zodiac ciphers. However, it is something that has been bothering me for years.

How do we know that Zodiac actually created legitimate ciphers, other than the one that was broken? In other words, in the world of ciphers, is it possible to '''know''' that a legitimate cipher exists but has not yet been broken? Is there a way to test for a real cipher that would eliminate the possibility that Zodiac just created gibberish with all his ciphers following the rather quick decoding of his first one?

It seems to me that it may have been in Zodiac's nature to do something like hoaxing ciphers. I have always ASSUMED that the unbroken ciphers were legitimate but just not yet cracked. What if, however, they were never intended to be broken simply because they were never true ciphers in the first place?

''And Dave's reply . . .''

It is certainly not a dumb question. But I don't think I have any smart answers.

''(Ed: it's nice to see that humility is not a lost art. Dave's answer, as you will see, is on the mark and easily understood.)''

I think the short answer is that we don't know that they are legitimate ciphers. Imagine a scenario in which the cipher author creates a stream of gibberish plaintext, and then enciphers it using a valid cryptographic approach, making the end result seem like a real cipher. In this case, there would be no real way to determine that the original plaintext is gibberish. I don't think there is a test that can determine this, especially considering the possibilities of other "schemes" at work, other than the one that was used on the 408-character cipher.

There is a real possibility that the 340 cipher contains no message whatsoever. The only way I can think of to prove this is to perform an exhaustive search of all possible solutions to the cipher under the assumption that it is a homophonic substitution cipher. But this is currently impossible because there are WAY too many solutions for computers to search through. Even if every computer on Earth was working on this problem, they would never finish going through all possible solutions any time soon.

The 340 cipher has 63 unique symbols. If one of 26 plaintext letters can be assigned to each symbol, then the number of possible solutions is 26 raised to the 63rd power. So, how many of those solutions would computers need to examine PER SECOND to finish within 100 years? The answer is about 4.4 x 10^80 solutions, or 440 million billion billion billion billion billion billion billion billion. This is LIGHT YEARS beyond what current computers are capable of.

According to [http://Top500.org Top500.org], the world's fastest supercomputer as of November, 2011, achieved a computational power of 10.51 Petaflop/s, or 10.51 quadrillion floating point operations per second. If you were somehow able to check a decryption solution of the 340 cipher using a single floating point operation, then this supercomputer could go through all of the possible solutions to the 340 cipher in about 1.3×10^57 years. By comparison, our humble universe is estimated to be only 13.7 x 10^9 years old!

So, we have to rely on smarter computer programs that take shortcuts by examining only the solutions that seem worth examining. This is what "hill- climbing" solvers such as [http://zkdecrypto.googlecode.com zkdecrypto] do. They look at some randomized solution, then try out new solutions to see if they are better than the older solutions. If they are better, the program continues to explore around the new solution. In this way, the programs "climb up a hill" of solutions of increasing quality. Sometimes they can find the right answer and other times they get stuck on smaller hills, failing to see the real hill off in the distance. Thus far, hill-climbing algorithms seem to be getting stuck on the smaller hills of the 340 cipher's landscape of solutions. Either there is still a distant, undiscovered hill out there with the correct solution perched at its top, or the entire landscape is covered in gibberish. You have to search the entire space to know for sure. And, even if we discovered that every possible point in the landscape is gibberish, there might be some "twist" to the 340 cipher's construction that we have failed to account for so far.

There may be ways to detect if a cipher is a hoax, however. In [http://members.fortunecity.com/jpeschel/gillog3.htm this interesting article] about the Beale ciphers, the author concludes that the unsolved cipher is a meaningless hoax because of the appearance of the strange sequence "ABFDE FGHII JKLMM NOHPP" when you decipher the code using the same key that was used on the solved Beale cipher. So, in this case, a researcher has produced real evidence that suggests the unsolved Beale cipher is a hoax. There is still debate, however, over whether that sequence is truly an artifact of an intentional hoax or of some other cryptographic remnant that might mean something else. So, the jury is apparently still out on that one and the mystery lingers on.

The 340 cipher seems like a real cipher because it contains several resemblances to real homophonic substitution ciphers:

1) It contains repetitions of bigrams and trigrams, as would normally occur if you created a homophonic substitution cipher.

2) There are repeated patterns of sequences that suggest the cipher author used a sequential homophonic assignment strategy, similar to what he did in the 408 cipher. The idea is to assign a few different cipher symbols to a common plaintext letter (such as "E"), to conceal its frequent occurrences. You can see some of the detected sequences [http://zodiackillerciphers.com/wiki/Brute_force_search_for_homophone_sequences#Results_for_340_cipher at this link.]

For example, if you removed every symbol except for l, *, and M, you get this sequence: [l*M] [l*M] [l*M] lM [l*M] [l*M] [l*M]. This sequence suggests a strong relationship between those symbols and some common plaintext letter.

3) The pivots suggest some sort of pattern in the underlying plaintext, or the inclusion of some other transposition strategy or other encipherment technique. More information on the pivots can be found [http://zodiackillerciphers.com/index.php?title=Pivots at this link.]

4) The distribution of individual symbols is similar to that of other real ciphers.

5) If you look at the number of repeated symbols per line, you'll see that some lines have few or no repeats, suggesting intentional assignment of unique symbols to those areas first.

So, there is evidence of intentional, deliberate encryption in the 340 cipher. There is also the little corrected backwards “K” that the cipher author made, which suggests a careful, deliberate process of encipherment. And, it is easy to create home-made ciphers that share many of the 340's traits. All of these factors continue to tantalize everyone.

Sorry I can't be more conclusive. It's still a big mystery, ultimately.

''When I read Dave's analysis, it became clear to me that Zodiac could well have created several legitimate ciphers. However, perhaps he made them too complex, or just did not design them well. Since his first cipher was decoded rather quickly, and by an amateur husband/wife team, perhaps Zodiac decided to make his future efforts “crack proof.”''

''At any rate, as Dave said, this is a genuine mystery. I now feel more certain that Zodiac did create meaningful ciphers. I also believe that there is reason to hope that, someday, the family of Zodiac cipher-breakers, like Dave, will surprise us all with some interesting solutions.''

''Thanks, Dave, for giving me my brain back!''

''Michael D. Kelleher, PhD''

'''David Oranchak'''
Computer scientist, software engineer, and puzzle enthusiast.
Creator/maintainer of the [http://zodiackillerciphers.com Zodiac Ciphers wiki].
You can contact Dave at doranchak at gmail dot com.

Cipher Legitimacy

2012-05-29T14:00:34Z

98.163.23.3: Created page with "'''(This article by true crime author [http://www.amazon.com/Michael-D.-Kelleher/e/B000APCA94/ref=ntt_athr_dp_pel_1 Michael Kelleher] is copied from the now defunct site ZodiacKi..."

'''(This article by true crime author [http://www.amazon.com/Michael-D.-Kelleher/e/B000APCA94/ref=ntt_athr_dp_pel_1 Michael Kelleher] is copied from the now defunct site ZodiacKillerCase.com)'''

''Like many other people who follow the Zodiac case, I have long been intrigued and regularly frustrated by the killer's ciphers. However, I simply don't have the kind of brain that can really come to grips with this aspect of the case. My mind seems to go on strike every time I try to approach the ciphers from an objective point of view.''

''Fortunately, there is a small community of exceptionally bright and tenacious individuals who have worked on Zodiac's ciphers for years. Among them is David Oranchak (see the Contributors Section), who has contributed to this site and who clearly has a grasp on this complex part of the Zodiac mystery.''

''Dave has become my cipher-guru. When I need to understand something about the ciphers, Dave always has a ready answer and he is able to put his thoughts into words in a direct and understandable way. So, I went to Dave with a question that has been rattling around in my mind for a long time. Here is the result of that exchange:''

Dave, I have a question, probably a dumb one, because I know so very little about the Zodiac ciphers. However, it is something that has been bothering me for years.

How do we know that Zodiac actually created legitimate ciphers, other than the one that was broken? In other words, in the world of ciphers, is it possible to '''know''' that a legitimate cipher exists but has not yet been broken? Is there a way to test for a real cipher that would eliminate the possibility that Zodiac just created gibberish with all his ciphers following the rather quick decoding of his first one?

It seems to me that it may have been in Zodiac's nature to do something like hoaxing ciphers. I have always ASSUMED that the unbroken ciphers were legitimate but just not yet cracked. What if, however, they were never intended to be broken simply because they were never true ciphers in the first place?

''And Dave's reply . . .''

It is certainly not a dumb question. But I don't think I have any smart answers.

''(Ed: it's nice to see that humility is not a lost art. Dave's answer, as you will see, is on the mark and easily understood.)''

I think the short answer is that we don't know that they are legitimate ciphers. Imagine a scenario in which the cipher author creates a stream of gibberish plaintext, and then enciphers it using a valid cryptographic approach, making the end result seem like a real cipher. In this case, there would be no real way to determine that the original plaintext is gibberish. I don't think there is a test that can determine this, especially considering the possibilities of other "schemes" at work, other than the one that was used on the 408-character cipher.

There is a real possibility that the 340 cipher contains no message whatsoever. The only way I can think of to prove this is to perform an exhaustive search of all possible solutions to the cipher under the assumption that it is a homophonic substitution cipher. But this is currently impossible because there are WAY too many solutions for computers to search through. Even if every computer on Earth was working on this problem, they would never finish going through all possible solutions any time soon.

The 340 cipher has 63 unique symbols. If one of 26 plaintext letters can be assigned to each symbol, then the number of possible solutions is 26 raised to the 63rd power. So, how many of those solutions would computers need to examine PER SECOND to finish within 100 years? The answer is about 4.4 x 10^80 solutions, or 440 million billion billion billion billion billion billion billion billion. This is LIGHT YEARS beyond what current computers are capable of.

According to [Top500.org Top500.org], the world's fastest supercomputer as of November, 2011, achieved a computational power of 10.51 Petaflop/s, or 10.51 quadrillion floating point operations per second. If you were somehow able to check a decryption solution of the 340 cipher using a single floating point operation, then this supercomputer could go through all of the possible solutions to the 340 cipher in about 1.3×10^57 years. By comparison, our humble universe is estimated to be only 13.7 x 10^9 years old!

So, we have to rely on smarter computer programs that take shortcuts by examining only the solutions that seem worth examining. This is what "hill- climbing" solvers such as [http://zkdecrypto.googlecode.com zkdecrypto] do. They look at some randomized solution, then try out new solutions to see if they are better than the older solutions. If they are better, the program continues to explore around the new solution. In this way, the programs "climb up a hill" of solutions of increasing quality. Sometimes they can find the right answer and other times they get stuck on smaller hills, failing to see the real hill off in the distance. Thus far, hill-climbing algorithms seem to be getting stuck on the smaller hills of the 340 cipher's landscape of solutions. Either there is still a distant, undiscovered hill out there with the correct solution perched at its top, or the entire landscape is covered in gibberish. You have to search the entire space to know for sure. And, even if we discovered that every possible point in the landscape is gibberish, there might be some "twist" to the 340 cipher's construction that we have failed to account for so far.

There may be ways to detect if a cipher is a hoax, however. In [http://members.fortunecity.com/jpeschel/gillog3.htm this interesting article] about the Beale ciphers, the author concludes that the unsolved cipher is a meaningless hoax because of the appearance of the strange sequence "ABFDE FGHII JKLMM NOHPP" when you decipher the code using the same key that was used on the solved Beale cipher. So, in this case, a researcher has produced real evidence that suggests the unsolved Beale cipher is a hoax. There is still debate, however, over whether that sequence is truly an artifact of an intentional hoax or of some other cryptographic remnant that might mean something else. So, the jury is apparently still out on that one and the mystery lingers on.

The 340 cipher seems like a real cipher because it contains several resemblances to real homophonic substitution ciphers:

1) It contains repetitions of bigrams and trigrams, as would normally occur if you created a homophonic substitution cipher.

2) There are repeated patterns of sequences that suggest the cipher author used a sequential homophonic assignment strategy, similar to what he did in the 408 cipher. The idea is to assign a few different cipher symbols to a common plaintext letter (such as "E"), to conceal its frequent occurrences. You can see some of the detected sequences here:

[http://zodiackillerciphers.com/wiki/Brute_force_search_for_homophone_sequences#Results_for_340_cipher]

For example, if you removed every symbol except for l, *, and M, you get this sequence: [l*M] [l*M] [l*M] lM [l*M] [l*M] [l*M]. This sequence suggests a strong relationship between those symbols and some common plaintext letter.

3) The pivots suggest some sort of pattern in the underlying plaintext, or the inclusion of some other transposition strategy or other encipherment technique. More information on the pivots can be found here:

[http://zodiackillerciphers.com/index.php?title=Pivots]

4) The distribution of individual symbols is similar to that of other real ciphers.

5) If you look at the number of repeated symbols per line, you'll see that some lines have few or no repeats, suggesting intentional assignment of unique symbols to those areas first.

So, there is evidence of intentional, deliberate encryption in the 340 cipher. There is also the little corrected backwards “K” that the cipher author made, which suggests a careful, deliberate process of encipherment. And, it is easy to create home-made ciphers that share many of the 340's traits. All of these factors continue to tantalize everyone.

Sorry I can't be more conclusive. It's still a big mystery, ultimately.

''When I read Dave's analysis, it became clear to me that Zodiac could well have created several legitimate ciphers. However, perhaps he made them too complex, or just did not design them well. Since his first cipher was decoded rather quickly, and by an amateur husband/wife team, perhaps Zodiac decided to make his future efforts “crack proof.”''

''At any rate, as Dave said, this is a genuine mystery. I now feel more certain that Zodiac did create meaningful ciphers. I also believe that there is reason to hope that, someday, the family of Zodiac cipher-breakers, like Dave, will surprise us all with some interesting solutions.''

''Thanks, Dave, for giving me my brain back!''

''Michael D. Kelleher, PhD''

'''David Oranchak'''
Computer scientist, software engineer, and puzzle enthusiast.
Creator/maintainer of the Zodiac Ciphers wiki: [http://zodiackillerciphers.com].
You can contact Dave at doranchak at gmail dot com.

Solved 340-character cipher (old version)

2012-05-29T13:41:46Z

98.163.23.3: /* Articles and information about the 340 cipher */

__FORCETOC__
Zodiac, the serial killer who terrorized Northern California in the late 1960s, sent four ciphers to local newspapers. The first cipher was separated into three different parts and each part was sent to Vallejo Times-Herald, the San Francisco Chronicle, and the San Francisco Examiner. The combination of all three parts formed a 408-letter cipher, which was decrypted one week after it was received. Zodiac also sent a 340-letter cipher, mailed on a card on November 8 1969, that remains unsolved to this day.

== Articles and information about the 340 cipher ==

[[File:340-cipher-hi-resolution.jpg|thumb|High-resolution scan of the 340-character cipher]]
[[File:Sfchron340cipher.png|thumb|Cipher as it appeared in the SF Chronicle on Nov 13, 1969 (Credit: Deborah Silva, who posts as Seagull on the Zodiac forums)]]

*[[Encyclopedia of observations]] - A collection of observations about the cipher text
*[[Comparison of cipher alphabets]]
*[[Comparison of character repetition rates]]
*[[Comparison of sequence repetition rates]]
*[[Levenshtein distance analysis]] - A look at the occurrences of repeated sequences that are not exact matches.
*[[Quadrant analysis]] - Do the n-gram counts improve If we split the cipher text into four quadrants?
*[[Quadrant analysis Part 2]] - An expansion of the previous quadrant analysis experiment. Is it possible to produce quadrant arrangements that increase the number and quality of homophones detected algorithmically?
*Information theory (entropy, randomness, etc)
*[[FBI analysis from Dan Olsen]]
*[[Cipher-related excerpts from case documents]]
*[[Word frequency analysis]] (word frequencies derived from a corpus of Zodiac correspondences)
*[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1339 Omnidirectional repetitions] - An investigation into patterns that repeat in arbitrary directions by following "snake-like" paths.
*[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=23179#p23179 "Complexification"] - Did the cipher author begin with a simpler set of cipher symbols, then "complexify" certain symbols to further flatten the symbol distributions?
*[[Substring ranking]] - Can we apply measurements that give us a way to find interesting sections of cipher text for focused attacks?
*[[Catalog of repeating fragments]] - A comprehensive list of portions of cipher text that occur more than once in the cipher text.
*[http://zodiackillercase.com/cipherlegit01.php Cipher Legitimacy] - Are the Zodiac ciphers real, or are they hoaxes?
*[[Corpus Experiments]] - A collection of corpus-based experiments performed on the Zodiac ciphers

== Homophone sequences ==
* Detection of homophone sequences in the cipher text
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1329&p=22906 Jurgen Koller's "Two-Times Repetition" approach]
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1329&p=22906#p22906 Computation of statistical significance of 6-symbol repetitions at the beginning of the cipher text]
**[[Brute force search for homophone sequences]] - Shows sequences detected in the 408 and 340 ciphers by performing brute force searches for sequences involving up to 7 symbols.

== The "Pivots" ==
*[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=22455#p22455 Reversible trigram patterns in the intersecting "pivots" of the cipher text]
*[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=1282&p=21758#p21758 Experiment to estimate odds of two intersecting "pivots" occurring by chance]
*[http://zodiac-ciphers.dreamhosters.com/wiki/index.php?title=Pivots Experimental results of generating pivots from large collection of plain text]

== Transpositions and other possible variations ==
Is the 340 cipher unsolved because it is not a simple homophonic substitution cipher like the 408 cipher? Here is a collection of considered possibilities:
*[[Oxcart]] - Does the 340 cipher's plaintext follow an "ox cart" path; that is, does it read alternately from left to right, then right to left?
*Vigenere
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1230 Vigenere encipherment prior to homophonic substitution]
*Playfair
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=20902#p20902 Playfair encipherment prior to homophonic substitution]
*Bifid
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=22038#p22038 Bifid encipherment prior to homophonic substitution]
*Many-to-many (one cipher symbol maps to multiple plaintext letters)
*Multiple encryption stages (examples: homophonic that has been rehomophoned, homophonic that has been transposed)
*Phonetic / nomenclator
*Was the cipher intended for use [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1390&start=20#p24191 by its author only?]

== Halloween Card ==
* Does the Halloween Card, mailed by the killer a year after the 340 cipher, contain clues about the 340?
**[http://www.kirps.com/web/main/resources/various/zodiac340/ Jos Kirps' article about interesting coincidences between the Halloween card and the 340 cipher]

Solved 408-character cipher

2012-05-29T13:41:11Z

98.163.23.3: /* Information, Analysis, Experiments */

__FORCETOC__
== Information, Analysis, Experiments ==
*[[Comparison of cipher alphabets]]
*Solution key
**[http://en.wikisource.org/wiki/Zodiac_Killer_letters#July_31st_1969 Transcription of the letter and the Hardens' solution]
**Donald and Bettye Harden's solution key. [http://www.zodiackillerfacts.com/gallery/albums/userpics/10001/1abcd_-_ZODIAC_-_July_69_Cipher_part_1_Vallejo_Times-Herald_w_Harden_worksheet.jpg Part 1] | [http://www.zodiackillerfacts.com/gallery/albums/userpics/10001/1bcdef_-_ZODIAC_-_July_69_Cipher_part_3_SF_Examiner_w_Harden_Worksheet.jpg Part 2] | [http://www.zodiackillerfacts.com/gallery/albums/userpics/10001/1cdef_-_ZODIAC_-_July_69_Cipher_part_2_CHRONICLE_w_Harden_worksheet.jpg Part 3]
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=1188 "Code key" sent to the Vallejo Police Department on August 10, 1969.] This was unavailable to the general public until recently.
**[http://www.scn.org/anon/dossiers/zodiac/zodiac.htm Tabular version of the key]
*[[Word frequency analysis (408)|Word frequency analysis of the 408 character cipher's plaintext]]
*[[Letter frequency analysis (408)|Letter frequency analysis of the 408 character cipher's plaintext]]
*[[Levenshtein distance analysis]] - A look at the occurrences of repeated sequences that are not exact matches.
*[[Quadrant analysis]] - Do the n-gram counts improve If we split the cipher text into four quadrants?
*[[Quadrant analysis Part 2]] - An expansion of the previous quadrant analysis experiment. Is it possible to produce quadrant arrangements that increase the number and quality of homophones detected algorithmically?
*[[Errors in the 408 cipher|Are the misspellings in the solution due to transcription errors?]]
*[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1339 Omnidirectional repetitions] - An investigation into patterns that repeat in arbitrary directions by following "snake-like" paths.
*[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=23179#p23179 "Complexification"] - Did the cipher author begin with a simpler set of cipher symbols, then "complexify" certain symbols to further flatten the symbol distributions?
*[[Substring ranking]] - Can we apply measurements that give us a way to find interesting sections of cipher text for focused attacks?
*[[Catalog of repeating fragments]] - A comprehensive list of portions of cipher text that occur more than once in the cipher text.
*[[Corpus Experiments]] - A collection of corpus-based experiments performed on the Zodiac ciphers

== Last 18 symbols of the 408 cipher ==
The last 18 letters of the decrypted plaintext are gibberish when using the same key that is used to decrypt the rest of the plaintext. What are the explanations for this?
*Possibility: The symbols were pulled down from symbols above the last row of the cipher text.
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=49&t=423 Glurk's original proposal]. There is good support for this explanation.
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=22217#p22217 Columnar repetition experiment]. This tests how often random selections of the last 18 symbols would "accidentally" produce the same number of columnar repetitions (12) that we see in the original 408 cipher.
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=22242#p22242 Second experiment which includes repeated tetragram]. This tests how often random selections of the last 18 symbols would "accidentally" produce the same number of columnar repetitions (12), where a tetragram repeats in the same column.
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=22254#p22254 Combinatorial calculation]. This is a calculation of the probability that random selection of the last 18 symbols would produce columnar repetitions that are observed in the unmodified 408 cipher.
*Possibility: A plaintext message is encoded somewhere in the last 18 symbols, using some other system of encipherment.
== Homophone sequences ==
*[[Homophone sequences]] - Several plaintext letters are assigned multiple homophones (ciphertext symbols) to conceal the language frequencies of the plaintext message. This page enumerates the sequences in which these homophones appear in the original ciphertext. What was the scheme used by the killer to select from the multiple homophones?
*Nick Pelling's articles on homophone sequences. [http://www.ciphermysteries.com/2011/09/13/thoughts-on-the-zodiac-killer-z408-and-z340-ciphers Part 1] | [http://www.ciphermysteries.com/2011/10/18/this-weeks-zodiac-killer-cipher-thoughts Part 2]
*[http://blog.jgc.org/2011/06/identification-of-homophone-sequences.html John Graham-Cumming's article on automatic detection of homophone sequences]
*John C. King & Dennis R. Bahler, "An Algorithmic Solution of Sequential Homophonic Ciphers". In their paper, King and Bahler describe an algorithm that can identify homophone sequences to simplify homophonic ciphers. [http://www.tandfonline.com/doi/abs/10.1080/0161-119391867827 Abstract]
*[[Brute force search for homophone sequences]] - Shows sequences detected in the 408 and 340 ciphers by performing brute force searches for sequences involving up to 6 symbols.

== Images ==

Images from Michael Butterfield (zodiackillerfacts.com) and Tom Voigt (zodiackiller.com):

{|
|-valign="top"
|[[File:Timesheraldcipher.jpg |thumb|Part 1 - From Vallejo Times - Herald Letter - July 31 1969]]
|[[File:Hardencipher1.jpg|thumb|100px|Harden's worksheet for Part 1]]
|
|-valign="top"
|[[File:Examinercipher.jpg|thumb|Part 2 - From San Francisco Examiner Letter - July 31 1969]]
|[[File:Hardencipher2.jpg|thumb|100px|Harden's worksheet for Part 2]]
|[[File:1bcdefg - ZODIAC - July 69 Cipher part 3 SF Examiner.jpg|thumb|Clearer scan of Part 2]]
|-valign="top"
|[[File:Chroniclecipher.jpg|thumb|Part 3 - From San Francisco Chronicle Letter - July 31 1969]]
|[[File:Hardencipher3.jpg|thumb|100px|Harden's worksheet for Part 3]]
|[[File:Chronicle Cipher July 1969.jpg|thumb|Clearer scan of Part 3]]
|}

Other images:

{|
|-valign="top"
|[[File:33.jpg|thumb|100px|High-resolution scan (unknown source)]]
|[[File:408-traveller1st-re-constructed.jpg|thumb|100px|traveller1st's recombination of the three sections]]
|}

[http://www.zodiackillerfacts.com/forum/viewtopic.php?p=23738#p23738 (traveller1st's post)]

Unsolved 32-character "map code" cipher

2012-05-03T21:11:11Z

98.163.23.3: Created page with "Work in progress"

Work in progress

Main Page

2012-05-03T21:10:33Z

98.163.23.3: /* Welcome to the Zodiac Ciphers wiki */

__FORCETOC__
==Welcome to the Zodiac Ciphers wiki==

This wiki is an attempt to gather all useful factual and verifiable information pertaining to the ciphers associated with the "Zodiac Killer". It is also a place to post results of experimental analysis of the ciphers.

There is so much information on these ciphers, but it is very hard to find in one place. This wiki tries to correct this problem by curating factual tidbits, experimental results, and analysis in a single location.

Site contents:

*[[Solved 408-character cipher]]
*[[Unsolved 340-character cipher]]
*[[Unsolved 13-character "My name is" cipher]]
*[[Unsolved 32-character "map code" cipher]]
*[[Webtoy's transcription scheme]] - ASCII representations of the ciphertext on this wiki use the [http://oranchak.com/zodiac/webtoy/ Webtoy's] ASCII transcriptions of the cipher.
*[[Software Tools]]
*[[Word counts from the Zodiac Killer's correspondences]]
*[[Research papers]] - Academic papers related to Zodiac ciphers in particular, and cryptography in general
*[[Cipher comparisons]] - Tabulation of measurements performed on an assortment of ciphers. Includes various test ciphers, and famous unsolved ciphers.

== Discredited or inconclusive solution attempts ==
*Corey Starliper (340 cipher): An arbitrary decryption system that permits the insertion of a predetermined message.
**[http://tewksbury.patch.com/articles/tewksbury-native-ive-cracked-the-code-of-the-zodiac-killer Original news article]
**[http://oranchak.com/zodiac/corey/hoax.html Analysis showing that Corey's solution is invalid]
*AK Wilks / Zander Kite (32, 408, and 340 ciphers): These decryption systems permit many arbitrary solutions due to vast spaces of possible selections.
**[http://unazod.com/Wilks_32.htm Original article]
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=1292 Analysis and discussion]
*Robert Graysmith (340 cipher): Selective use of anagramming and other techniques, resulting in an incoherent message typical of anagram-based solutions.
**[http://www.zodiackiller.com/mba/zc/26.html Analysis and discussion]
*John Cecil: Relaxes the "one plaintext letter per symbol" constraint, resulting in easily fitting a pre-conceived plaintext.
** [http://zodiackillersolved.blogspot.com/2008/12/340-cipher-solution.html Post]
*Hal Kravcik
** [http://www.340cipher.com/340sol2.php Post]
*Chris Farmer / OPORD
** [http://www.opordanalytical.com/articles1/zodiac-340.htm Post]
*rand
** [http://zodiackiller.21.forumer.com/a/posts.php?topic=2330&start=0 Post]
*Robert P. Ackerman
** [http://zodiacevidence.co.uk/default.aspx?g=posts&t=29&find=unread Post]
** [http://zodiackillertruth.websitetoolbox.com/post?id=5032922 Post]
*back2good
** [http://www.opordanalytical.com/phpBB3/viewtopic.php?f=87&t=538&start=0 Post]
*AuthUser
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=1533 Post]
*Pax
** [http://www.zodiackiller.com/mba/zc/1111.html Post]
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=2360 Post]
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4668 Post]
*dronjom
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4804 Post]
*Rembrandt
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=5149 Post]
*Hal 9000
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4459&start=50&postdays=0&postorder=asc#93915 Post]
*Miscellaneous
** [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=590 Post]
[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1196 Discussions regarding these and other solution attempts]

== See Also ==

* [http://zodiac-ciphers.dreamhosters.com/blog The Zodiac Ciphers blog] - A place for announcements and news related to the Zodiac ciphers.
* [http://oranchak.com/zodiac/webtoy/stats.html CryptoScope] - The newest section of the "zodiac webtoy". Analyze statistical features and patterns in the Zodiac ciphers and more.
* [http://oranchak.com/zodiac/webtoy/index.html Zodiac Cipher Webtoy] - Plug in your own decryption attempts with this online tool.
* [http://en.wikisource.org/wiki/Zodiac_Killer_letters Transcriptions of letters associated with the Zodiac killer]
* [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=359 "Crypto 101" by glurk] - An introduction to simple cryptography concepts.
* [http://listverse.com/2007/10/01/top-10-uncracked-codes/ Top 10 uncracked codes] (Curiously, the Zodiac codes are missing)
* [http://www.ciphermysteries.com/ Cipher Mysteries] - Nick Pelling's fascinating site, filled with articles about mysterious unsolved historical and contemporary ciphers, including the Zodiac ciphers.

You can contact me here:
[[File:F627b7cf6b48dbceae66c0fd3d23392c.png]]
Email me if you want an account here. Account creation is currently disabled due to abuse by spammers.

Main Page

2012-05-03T21:06:18Z

98.163.23.3: /* Welcome to the Zodiac Ciphers wiki */

__FORCETOC__
==Welcome to the Zodiac Ciphers wiki==

This wiki is an attempt to gather all useful factual and verifiable information pertaining to the ciphers associated with the "Zodiac Killer". It is also a place to post results of experimental analysis of the ciphers.

There is so much information on these ciphers, but it is very hard to find in one place. This wiki tries to correct this problem by curating factual tidbits, experimental results, and analysis in a single location.

Site contents:

*[[Solved 408-character cipher]]
*[[Unsolved 340-character cipher]]
*[[Unsolved 13-character "My name is" cipher]]
*[[Unsolved 32-character "bus bomb" cipher]]
*[[Webtoy's transcription scheme]] - ASCII representations of the ciphertext on this wiki use the [http://oranchak.com/zodiac/webtoy/ Webtoy's] ASCII transcriptions of the cipher.
*[[Software Tools]]
*[[Word counts from the Zodiac Killer's correspondences]]
*[[Research papers]] - Academic papers related to Zodiac ciphers in particular, and cryptography in general
*[[Cipher comparisons]] - Tabulation of measurements performed on an assortment of ciphers. Includes various test ciphers, and famous unsolved ciphers.

== Discredited or inconclusive solution attempts ==
*Corey Starliper (340 cipher): An arbitrary decryption system that permits the insertion of a predetermined message.
**[http://tewksbury.patch.com/articles/tewksbury-native-ive-cracked-the-code-of-the-zodiac-killer Original news article]
**[http://oranchak.com/zodiac/corey/hoax.html Analysis showing that Corey's solution is invalid]
*AK Wilks / Zander Kite (32, 408, and 340 ciphers): These decryption systems permit many arbitrary solutions due to vast spaces of possible selections.
**[http://unazod.com/Wilks_32.htm Original article]
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=1292 Analysis and discussion]
*Robert Graysmith (340 cipher): Selective use of anagramming and other techniques, resulting in an incoherent message typical of anagram-based solutions.
**[http://www.zodiackiller.com/mba/zc/26.html Analysis and discussion]
*John Cecil: Relaxes the "one plaintext letter per symbol" constraint, resulting in easily fitting a pre-conceived plaintext.
** [http://zodiackillersolved.blogspot.com/2008/12/340-cipher-solution.html Post]
*Hal Kravcik
** [http://www.340cipher.com/340sol2.php Post]
*Chris Farmer / OPORD
** [http://www.opordanalytical.com/articles1/zodiac-340.htm Post]
*rand
** [http://zodiackiller.21.forumer.com/a/posts.php?topic=2330&start=0 Post]
*Robert P. Ackerman
** [http://zodiacevidence.co.uk/default.aspx?g=posts&t=29&find=unread Post]
** [http://zodiackillertruth.websitetoolbox.com/post?id=5032922 Post]
*back2good
** [http://www.opordanalytical.com/phpBB3/viewtopic.php?f=87&t=538&start=0 Post]
*AuthUser
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=1533 Post]
*Pax
** [http://www.zodiackiller.com/mba/zc/1111.html Post]
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=2360 Post]
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4668 Post]
*dronjom
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4804 Post]
*Rembrandt
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=5149 Post]
*Hal 9000
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4459&start=50&postdays=0&postorder=asc#93915 Post]
*Miscellaneous
** [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=590 Post]
[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1196 Discussions regarding these and other solution attempts]

== See Also ==

* [http://zodiac-ciphers.dreamhosters.com/blog The Zodiac Ciphers blog] - A place for announcements and news related to the Zodiac ciphers.
* [http://oranchak.com/zodiac/webtoy/stats.html CryptoScope] - The newest section of the "zodiac webtoy". Analyze statistical features and patterns in the Zodiac ciphers and more.
* [http://oranchak.com/zodiac/webtoy/index.html Zodiac Cipher Webtoy] - Plug in your own decryption attempts with this online tool.
* [http://en.wikisource.org/wiki/Zodiac_Killer_letters Transcriptions of letters associated with the Zodiac killer]
* [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=359 "Crypto 101" by glurk] - An introduction to simple cryptography concepts.
* [http://listverse.com/2007/10/01/top-10-uncracked-codes/ Top 10 uncracked codes] (Curiously, the Zodiac codes are missing)
* [http://www.ciphermysteries.com/ Cipher Mysteries] - Nick Pelling's fascinating site, filled with articles about mysterious unsolved historical and contemporary ciphers, including the Zodiac ciphers.

You can contact me here:
[[File:F627b7cf6b48dbceae66c0fd3d23392c.png]]
Email me if you want an account here. Account creation is currently disabled due to abuse by spammers.

Main Page

2012-05-03T14:54:22Z

98.163.23.3: /* See Also */

__FORCETOC__
==Welcome to the Zodiac Ciphers wiki==

This wiki is an attempt to gather all useful factual and verifiable information pertaining to the ciphers associated with the "Zodiac Killer". It is also a place to post results of experimental analysis of the ciphers.

There is so much information on these ciphers, but it is very hard to find in one place. This wiki tries to correct this problem by curating factual tidbits, experimental results, and analysis in a single location.

Site contents:

*[[Solved 408-character cipher]]
*[[Unsolved 340-character cipher]]
*[[Unsolved 13-character "My name is" cipher]]
*[[Webtoy's transcription scheme]] - ASCII representations of the ciphertext on this wiki use the [http://oranchak.com/zodiac/webtoy/ Webtoy's] ASCII transcriptions of the cipher.
*[[Software Tools]]
*[[Word counts from the Zodiac Killer's correspondences]]
*[[Research papers]] - Academic papers related to Zodiac ciphers in particular, and cryptography in general
*[[Cipher comparisons]] - Tabulation of measurements performed on an assortment of ciphers. Includes various test ciphers, and famous unsolved ciphers.

== Discredited or inconclusive solution attempts ==
*Corey Starliper (340 cipher): An arbitrary decryption system that permits the insertion of a predetermined message.
**[http://tewksbury.patch.com/articles/tewksbury-native-ive-cracked-the-code-of-the-zodiac-killer Original news article]
**[http://oranchak.com/zodiac/corey/hoax.html Analysis showing that Corey's solution is invalid]
*AK Wilks / Zander Kite (32, 408, and 340 ciphers): These decryption systems permit many arbitrary solutions due to vast spaces of possible selections.
**[http://unazod.com/Wilks_32.htm Original article]
**[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=1292 Analysis and discussion]
*Robert Graysmith (340 cipher): Selective use of anagramming and other techniques, resulting in an incoherent message typical of anagram-based solutions.
**[http://www.zodiackiller.com/mba/zc/26.html Analysis and discussion]
*John Cecil: Relaxes the "one plaintext letter per symbol" constraint, resulting in easily fitting a pre-conceived plaintext.
** [http://zodiackillersolved.blogspot.com/2008/12/340-cipher-solution.html Post]
*Hal Kravcik
** [http://www.340cipher.com/340sol2.php Post]
*Chris Farmer / OPORD
** [http://www.opordanalytical.com/articles1/zodiac-340.htm Post]
*rand
** [http://zodiackiller.21.forumer.com/a/posts.php?topic=2330&start=0 Post]
*Robert P. Ackerman
** [http://zodiacevidence.co.uk/default.aspx?g=posts&t=29&find=unread Post]
** [http://zodiackillertruth.websitetoolbox.com/post?id=5032922 Post]
*back2good
** [http://www.opordanalytical.com/phpBB3/viewtopic.php?f=87&t=538&start=0 Post]
*AuthUser
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=1533 Post]
*Pax
** [http://www.zodiackiller.com/mba/zc/1111.html Post]
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=2360 Post]
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4668 Post]
*dronjom
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4804 Post]
*Rembrandt
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=5149 Post]
*Hal 9000
** [http://zodiackiller.21.forumer.com/viewtopic.php?t=4459&start=50&postdays=0&postorder=asc#93915 Post]
*Miscellaneous
** [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=590 Post]
[http://www.zodiackillerfacts.com/forum/viewtopic.php?f=50&t=1196 Discussions regarding these and other solution attempts]

== See Also ==

* [http://zodiac-ciphers.dreamhosters.com/blog The Zodiac Ciphers blog] - A place for announcements and news related to the Zodiac ciphers.
* [http://oranchak.com/zodiac/webtoy/stats.html CryptoScope] - The newest section of the "zodiac webtoy". Analyze statistical features and patterns in the Zodiac ciphers and more.
* [http://oranchak.com/zodiac/webtoy/index.html Zodiac Cipher Webtoy] - Plug in your own decryption attempts with this online tool.
* [http://en.wikisource.org/wiki/Zodiac_Killer_letters Transcriptions of letters associated with the Zodiac killer]
* [http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=359 "Crypto 101" by glurk] - An introduction to simple cryptography concepts.
* [http://listverse.com/2007/10/01/top-10-uncracked-codes/ Top 10 uncracked codes] (Curiously, the Zodiac codes are missing)
* [http://www.ciphermysteries.com/ Cipher Mysteries] - Nick Pelling's fascinating site, filled with articles about mysterious unsolved historical and contemporary ciphers, including the Zodiac ciphers.

You can contact me here:
[[File:F627b7cf6b48dbceae66c0fd3d23392c.png]]
Email me if you want an account here. Account creation is currently disabled due to abuse by spammers.