back to article FBI confirms Zodiac Killer's 340 cipher solved by trio of amateur math and software codebreakers

A team of code breakers has solved a cipher attributed to the Zodiac Killer, a serial murderer known for a Northern California killing spree in the late 1960s who has still not been identified or apprehended. David Oranchak, a US-based software developer, Sam Blake, a mathematician based in Australia, and Jarl Van Eycke, a …

  1. Anonymous Coward
    Anonymous Coward

    They've finally caught Ted Cruz?

    1. jake Silver badge

      Couldn't have been Cruz, sadly.

      Cruz is one of those fucking dimwits that think backdoors in encryption can only be used by the good guys. He clearly couldn't be the author of the cypher.

      1. Mike 16

        Re: Couldn't have been Cruz, sadly.

        Saying is not believing. What a given person like Ted Cruz _says_ has near zero correlation to what he _believes_, although it probably reflects what he wants other to believe.

        (BTW, were I given Ted Cruz, I be frantically checking the return policy)

    2. Anonymous Coward
      Anonymous Coward

      Fuck off with tired old meme.

      1. Throatwarbler Mangrove Silver badge
    3. Androgynous Cupboard Silver badge

      He was always a strange one. He likes to eat hair, for pete's sake:

      https://www.youtube.com/watch?v=v75wCTMZoSY

    4. fandom

      Because, obviously, political nuts will be nuts.

  2. Anonymous Coward
    Anonymous Coward

    Good at cipher

    Not so good at spelling

    Oh, and a killer

    1. Anonymous Coward
      Anonymous Coward

      "Not so good at spelling"

      Yes, that probably made deciphering mode complex. I believe

      1. StargateSg7

        Re: "Not so good at spelling"

        There is an unspoken clue in his spelling of paradice (i.e. should be paradise!) which indicates a POSSIBLE English or Canadian heritage where words such as Defence, Offence, etc use CE as the replacement for SE in their spelling of certain words.

        This Zodiac killer has LIKELY been exposed to such spellings which would be indicators of possible schooling locations or the heritage of the parents. I suspect that the Zodiac Killer thought ALL such words containing the U.S.-specific "se" word endings could be replace with "ce".

        This too indicates that while he may have been intelligent at a base level, but his actual schooling may have been cut short PROBABLY DUE to financial issues or parental neglect issues. This could help investigators NARROW DOWN suspects to those with British/Canadian-centric schooling systems experience or those parents who were educated in such environs and to persons who left high school suddenly.

        I should also note the actual symbols used within teh original messages have certain clues. I especially notice on the upside down "6" which I suspect is actually a nine, indicates a person who either has/had a hand injury OR is actually left handed. The drawing of the glyphs in the original messages specifically indicates to me variable handedness possible due to injury, muscle weakness or trying to write with the non-dominant hand. Again, this could help narrow down the cope of possible suspects.

        For me, the most interesting thing about the entire cases is finding out what the BASE MOTIVE was! The deciphered message in itself speaks of inherent childhood rage due to likely severe sudden onset hardship or a declines from an already dicey living situation into a much worse one when this person was young.

        The message says to me that that for a period of time probably until his teens, the Zodiac Killer had some small semblance of a normal childhood but for some POSSIBLE medical issue, mental issue or financial issue that suddenly cropped up with one or both parental figures that resulted in a sudden drop in living standard and a subsequent severe decline in coping abilities (i.e. not being able to keep their heads above water!) caused all sorts of problems that resulted in a long-term build-up of rage against society.

        He was targeting young couples as his victims because he had a very difficult time coupling in his teens and early adult years, and when he did find a partner, the resulting situation was not to his expectations (i.e. possibly got a young woman pregnant who then rejected him or had a fling with a woman who lied about having other partners!).

        Whatever the case was, the targeting of couples is a representation of ANGER AT YOUNG COUPLES being happy, which was a situation he was unable to attain.

        Of all the suspects listed, the one named Earl Van Best, Jr. comes closest to the childhood and young adulthood situation indicated by the clues in the case itself and the messages. The biological son only needs to supply a DNA swab to see if it matches what was recovered on the postage stamps used in sending the letters. It would be definitive proof and a subpoena could easily be made for such sampling. It would at least RULE OUT the suspect if the DNA doesn't match!

        What this case DOES SAY in a general sense, is that crowd-based puzzle-solving, A.I-based computer processing and DNA forensics will become ever more important in order to solve current and past cold case files. I suspect there are a lot more cases ready to be solved by enthusiast sleuths and I welcome their involvement in such cases.

        Now, if ONLY we could find out why JFK was murdered and by whom? ...AND... where Jimmy Hoffa's body is?

        V

        1. Alister

          Re: "Not so good at spelling"

          There is an unspoken clue in his spelling of paradice (i.e. should be paradise!) which indicates a POSSIBLE English or Canadian heritage where words such as Defence, Offence, etc use CE as the replacement for SE in their spelling of certain words.

          Rubbish. Paradise is not, and has never been spelled with a C in British English or Commonwealth English. The use of C in words such as defence and offence is very specifically after a consonant, not a vowel, so no-one educated in British English would extrapolate that to other words ending SE.

          1. Anonymous Coward
            Anonymous Coward

            Re: "Not so good at spelling"

            >> Rubbish. Paradise is not, and has never been spelled with a C in British English or Commonwealth English.

            Exactly. Which is what the original poster said. Read his post again.

          2. StargateSg7

            Re: "Not so good at spelling"

            The Zodiac Killer POSSIBLY was exposed to spelling where CE over SE is a common occurrence. The killer WAS intelligent but due to a likely cut-short education MAY HAVE extrapolated the already-learned rules for his POSSIBLY English/Canadian spelling exposure into thinking that ALL words with SE could be replaced with CE.

            Again, I am making a GUESS what the reasoning WHY he misspelled "Paradice"multiple times! My reasoning is that the Zodiac Killer was exposed to UK/Canadian spelling rules and thought a word LIKE Paradise would ALSO be spelled as "Paradice".

            This narrows down the possible suspects.

            You people NEED to read more diligently! ...OR.... Maybe I need to dumb down my writings for the ignoble, the quasi-literate and/or the lackadaisical among this ilk of Register reader.

            V

        2. werdsmith Silver badge

          Re: "Not so good at spelling"

          John Milton in 1667 didn’t use a C in Parasdise even.

          How strange that someone should write a long post based on this false idea.

          1. Anonymous Coward
            Anonymous Coward

            Re: "Not so good at spelling"

            He didn't. Re-read what he wrote!

            1. werdsmith Silver badge

              Re: "Not so good at spelling"

              He didn't. Re-read what he wrote!

              I read, and understood it. There is no mileage in the idea that people who are used to spelling some words in a certain way would be inclined to misspell another word as a result

              It's basically shit.

        3. ICPurvis47
          Boffin

          Re: "Not so good at spelling"

          "Now, if ONLY we could find out why JFK was murdered and by whom?"

          JFK was accidentally shot by one of the Secret Service men in the Cadillac that was following JFK in the Lincoln. Hickey was not supposed to be in that car, but as the three SS men who were supposed to be there were ruled unfit for duty (they were observed at 3AM in a bar with several Ladies of Negotiable Affection), Hickey was moved from the Vehicle Preparation Team to the Active Support Team. When Oswald's first shot rang out, Hickey grabbed for the .22 repeating rifle that was on the floor beneath his feet. On Oswalds second (and last) shot, he stood up and the gun went off (the third shot). The bullet passed over the top of the Cadillac's windscreen and entered the back of Kennedy's skull, making a 1/4" hole (too small for the 6.5mm FMJ used by Oswald). The hollow nosed bullet then fragmented inside Kennedy's head, blowing off a hand sized patch of his right forehead.

          All of this has been explained in a series of investigations, which are available to view. There have been many other theories, but this is the only one that stands up to close scrutiny.

          1. Anonymous Coward
            Anonymous Coward

            Re: "Not so good at spelling"

            > but this is the only one that stands up to close scrutiny.

            Ok, I'll bite. So what you're saying is: a shot rang out (either from Oswald or persons unknown) and the response of the Secret Service in the car behind JFK was to 'accidentally' aim at and shoot JFK, rather than look for the gunman's location and return fire towards the Book Depository or the Grassy Knoll or in fact return fire in any direction other than towards JFK?

            1. ICPurvis47
              Boffin

              Re: "Not so good at spelling"

              Hickey did not aim, he stood up on the upholstery of the back seat and, as the car accelerated, lost his balance. In contravention of all the regulations, the gun was "Hot", ie there was a round in the chamber and the safety was off, because "that's the way we do it". As he lost his balance, he tightened his grip on the gun, and it went off. There was no intention on his part to shoot Kennedy, he was trying to ascertain where the shots had come from, but failed. Oswald's first shot was deflected by the sight board of the traffic light, and hit the kerb, throwing up a spray of stone chips which hit Kennedy in the face. He exclaimed "I'm hit", at which point Governor Connely turned around to see if Kennedy was OK. Oswald's second shot entered the back of Kennedy's neck and exited through his larynx, then passed through Connely's shoulder, wrist, and thigh, before lodging in the back of the front passenger seat. The reason for there being three cartridges at the sniper's nest was because one always keeps a spent cartridge in the chamber to prevent the firing pin from being damaged,should the trigger be pulled against an empty chamber. Thus, the first cartridge, separate from the others near the window, was ejected when Oswald operated the bolt to bring the first live cartridge into the chamber.

              1. Anonymous Coward
                Anonymous Coward

                Re: " because one always keeps a spent cartridge in the chamber."

                Absolute rubbish, you keep a bolt action rifle uncocked on an empty chamber, so pulling the trigger risks/does nothing. Cycling the bolt will cock the firearm and load a live round into the chamber. You'll find yourself in the brig for leaving an empty case in the chamber.

                Show clear and repeat after me, "I have no live rounds or empty cases in my possession, Sir!"

                1. ICPurvis47

                  Re: " because one always keeps a spent cartridge in the chamber."

                  Nevertheless, that's what the finding was. I remind you, although Oswald was a trained sniper, he was disaffected, and was using a non-US rifle.

                  1. Yet Another Anonymous coward Silver badge

                    Re: " because one always keeps a spent cartridge in the chamber."

                    >JFK was accidentally shot by one of the Secret Service men in the Cadillac

                    I thought he was shot by a time-travelling JFK?

                    There was a BBC documentary on it starring Craig Charles

                    1. Andy1

                      Re: " because one always keeps a spent cartridge in the chamber."

                      Ha Ha Red Dwarf a documentary, I like your lack of reality!

                      1. jake Silver badge

                        Re: " because one always keeps a spent cartridge in the chamber."

                        You've honestly never seen the word documentary used in the sardonic sense?

                        I suddenly feel very, very old and jaded.

                  2. StargateSg7

                    Re: " because one always keeps a spent cartridge in the chamber."

                    Not that many people know this, but Lee Harvey Oswald WAS a former Marine and Marines ARE TRAINED to snipe! Every last Marine CAN hit a target at 250 yards minimum even with an el-cheapo old-style Garand rifle or a .22 LR!

                    It merely takes training and practice! With modern .50 CAL rifles, I can hit targets hour-after-hour out to 1100 metres dead-on! I can do that almost with my eyes closed! With a better high-velocity specialty rifle and good spotter/wind envelope expert helping me, I can hit out to 2500 metres dead-on. So a person that is TRULY MOTIVATED (i.e. Oswald), even the worst weapon can be utterly lethal in the "right" hands.

                    While Oswald was most likely the actual shooter of JFK, he had help in some way! Be it financial, training-wise, mental preparedness help and even political help. The question is WHO helped and WHEN did they start the process of radicalizing Oswald ??? After enough personal research, I am beginning to believe multiple parties had a hand and I am also beginning to suspect a case of "The Enemy of My Enemy is My Friend" situation arose where two or more normally antagonistic parties (i.e. MAFIA, GRU, Castro, CIA, etc) began to cooperate to eliminate their common foe!

                    This is probably WHY two shooters were present. One real shooter (i.e. Oswald) and a secret backup shooter from another 2nd or 3rd party group to make sure the job got done if teh first one failed!

                    V

              2. Cynic_999

                Re: "Not so good at spelling"

                I was trained in the use of several different rifles, and have not heard of the practice of keeping an empty cartridge in the chamber, nor was I ever told that any damage would result from "firing" a weapon with an empty chamber whether the weapon had a floating or fixed firing pin. In fact "clearing" a weapon often involved cocking and then pulling the trigger on an empty chamber.

              3. Anonymous Coward
                Anonymous Coward

                Re: "Not so good at spelling"

                > The reason for there being three cartridges at the sniper's nest was because one always keeps a spent cartridge in the chamber to prevent the firing pin from being damaged,should the trigger be pulled against an empty chamber.

                What utter tosh! If a cocked rifle is 'fired' with no round in the chamber then the firing pin makes contact with nothing but thin air.

                1. jake Silver badge

                  Re: "Not so good at spelling"

                  "If a cocked rifle is 'fired' with no round in the chamber then the firing pin makes contact with nothing but thin air."

                  You have obviously haven't closely eyeballed very many firearms, nor thought about it with any degree of concentration.

                  Think about it ... if the firing pin makes contact with nothing but air, how far away from the firearm does the shooter have to walk to retrieve it following every shot?

                  With that said, some firearms are more susceptible to damage caused by dry firing than others. Historical and most rim-fire weapons should never be dry-fired, but many more modern designs have fewer issues. When in doubt, don't dry fire unless you really have a need to do so. There is a reason that most of the world's high-end hand-made rifles and shotguns are shipped from the manufacturer with a tool (or tools) called a Snap Cap.

                  For the record, I have never heard an expert suggest keeping a fired round in the chamber for any reason whatsoever.

            2. StargateSg7

              Re: "Not so good at spelling"

              The problem is that modern digital processing of audio recordings taken at the time of the JFK shooting are DISTINCTLY NOTABLE in that multiple shots were fired from DIFFERENT DIRECTIONS! The math doesn't lie! We CAN detect multiple gunshots and process the type, speed, direction and scope of the reverberations saved within the recordings even by the poor quality microphones of the day.

              There were TWO shooters! The one from the Book repository (aka Oswald) and another from a direction almost polar opposite. It looks like the 2nd shooter missed their shots completely!

              The MAFIA at the time had serious issues with Robert Kennedy who was tasked by JFK to look into government corruption so that would one motive. Fidel Castro's regime was another who didn't like JFK so that is Motive #2.

              Then we have the Soviet GRU spy agency that was at the time very antagonistic towards the Soviet Premier Nikita Khrushchev's governing principles (he wanted to liberalize the economy!). They wanted their own politicos in office and an assassination of Kennedy would have provided enough internal shakeup in the Soviet Union that the GRU could then remove Khrushchev via an internal coup to install their own puppet as the Soviet Premier. A few years later he was removed for very different reasons and a more ruthless dictator was installed (i.e. Leonid Brezhnev).

              AND FINALLY, the CIA itself was under attack by JFK for its own internal corruption (i.e. funds, guns and drugs being run in and out of Central and South America plus Vietnam/Laos/Cambodia/Thailand in the late 1950's/Early 1960's by actual CIA operatives which were all admitted to by various agents themselves and within government originated documents from the 1980's!) They had ample desire to get rid of JFK! It also doesn't help the case that MANY upper-level CIA execs and operatives HATED JFK and just seethed at his presidency.

              V

          2. Cynic_999

            Re: "Not so good at spelling"

            Having shot many .22 rounds, I doubt very much that they would have enough power to go completely through someone's head.

            1. Anonymous Coward
              Anonymous Coward

              Re: "Not so good at spelling"

              I can assure you that a .22 will enter the skull. Exiting would be unlikely. A .22LR would have much more power than a short or a long, of course.

              I'm not familiar with the typical armament of early 1960s Secret Service, but a .22 is a strange choice of weapon. Perhaps there was a credible threat from a pack of Communist squirrels in Dallas?

        4. mevets

          Not so good at history?

          It is a funny sort of causation where the original is altered by the derivative. At best, you might suggest that USA-English (aka merkin) transliterated many common idioms; at worst a broader swipe about literacy.

          X

    2. Anonymous Coward
      Anonymous Coward

      Re: Good at cipher

      It's someone from ISIS with a gambling addiction who went back in time to wreak havoc....

    3. Fruit and Nutcase Silver badge

      Re: Good at cipher

      Not so good at spelling

      That's either genuine or a red herring. If genuine, it could be a vital clue if "PARADICE" as a form of spelling of the intended word is rare.

      1. Dave 126 Silver badge

        Para-dice

        I like the concept of 'para [beyond, adjacent to] dice [symbols of chance].'

        However I'm sure it was just a spelling mistake. Musings on fate and chance didn't appear to be a part of this asshole's make-up.

  3. herman Silver badge
    WTF?

    Georgian or Armenian

    It looks like English written in one of the East European alphabets.

    1. Chris G

      Re: Georgian or Armenian

      No, nothing like Georgian or Armenian script and little similarity to cyrillic. My guess is he took the English alphabet, added a few common symbols including maths and flipped them around or reoriented them.

      e.g. the Plimsoll line symbol is shown both horizontal and vertical.

  4. Anonymous Coward
    Facepalm

    Auguste Kerckhoffs

    Kerckhoffs's principle, one of the tenets of modern cryptography, was demonstrated to be wrong here. The principle is that a cryptosystem should be secure even if everything about the system, except the key, is public knowledge.

    Despite weak keys, this cipher was protected for half a century from very determined efforts to break into it, doubtless including ones by the NSA, because people did not understand the encryption mechanism.

    1. cookieMonster Silver badge

      Re: Auguste Kerckhoffs

      I’d hazard a guess that if the NSA had a go at that they’d have cracked it. I’m also pretty sure that they’d tell no one.

      1. mark l 2 Silver badge

        Re: Auguste Kerckhoffs

        If the NSA had cracked it they would have kept it a secret so they could use it for themselves, like they do with all those Windows exploits they find

        1. Kabukiwookie

          Re: Auguste Kerckhoffs

          Find?

          You mean handed to them by MS, which has been happily playing ball with the NSA since at least 2007.

      2. Anonymous Coward
        Happy

        Re: Auguste Kerckhoffs

        I’d hazard a guess that if the NSA had a go at that they’d have cracked it.

        The FBI is the main federal main law-enforcement and domestic intelligence agency, and works hand-in-glove with the NSA on things like the collection and surveillance of US citizens, for example with the 1994 Communications Assistance for Law Enforcement Act.

        The FBI doubtless asked the NSA for assistance, because why wouldn't they? The FBI don't do code-breaking - that's the NSA's job. I am sure the FBI regularly ask other federal agencies for assistance - e.g. do you think that they scrupulously avoid any contact whatsoever with the U.S. Fire Administration if they think it could help in cases involving suspected arson? Having asked the NSA, do you think the NSA would refuse the FBI? They might have required the FBI to pay for the work, but I really can't see them refusing.

        1. Jellied Eel Silver badge

          Re: Auguste Kerckhoffs

          The FBI doubtless asked the NSA for assistance, because why wouldn't they? The FBI don't do code-breaking - that's the NSA's job. I am sure the FBI regularly ask other federal agencies for assistance

          I guess one problem is how well various law enforcement agencies worked together 50 years ago, and technology limitations. The movie Zodiac, based on Grayling's book & Toschi's recollections showed some of this. It didn't show the FBI having much involvement, but did show issues like some police departments not having fax machines. Or just information sharing & procedural challenges, like figuring out which police force had jurisdiction.

          I think the book and the movie are good insights to the challenges and frustrations law enforcement faced attempting to solve crimes like these. And ultimately led to systems like the FBI's VICAP database, which only appeared in 1985, then made available to police agencies in 2008. Plus advances in forensics, eg in 1969, blood could be typed. In 2020, typed and comprehensive DNA analysis and possible familial linking.

          But ZK also seemed to be fairly smart, and forensically aware, so may not have left much trace evidence to work with, plus seemed to enjoy taunting & trying to mislead the police. So I guess it's possible that either the code doesn't contain the real name, or conceivably could name someone else, eg Leigh Allen, if the real ZK was aware of them being a prime suspect. But I think it's neat that LEOs still work cold cases like this to try and bring closure.

    2. Mark 85

      Re: Auguste Kerckhoffs

      Other articles say that the text was not written left to right but diagonally which probably stopped many who might have decoded it. Zodiac did some thinking outside the box.

      1. stiine Silver badge

        Re: Auguste Kerckhoffs

        re: mark85

        No, he copied an ancient Greek scytale.

    3. Pascal Monett Silver badge

      I think it would be more because 51 years ago, nobody had the means to test 650000 variations in anything resembling a human lifetime.

      Cryptographic experts today have likely not invented new ways of decrypting things, how to decrypt was known decades ago. It's just that, today, computers make everything faster so you can try more things and stumble upon the solution.

      This was a brute-force hack. Beck then, they didn't have the means to do it.

      1. Anonymous Coward
        Happy

        I think it would be more because 51 years ago, nobody had the means to test 650000 variations in anything resembling a human lifetime.

        Computers were common enough devices by 1969, when the letter was written.

        The largest computer manufacturer at the time, IBM, had a quarter of a million employees and was just about to replace its very popular System/360 line of computers with the System/370 line.

        1. Anomalous Cowshed

          I suppose that with that many employees, and a computer being a computer, after all, whether in 1969 or 2020, the performances can't have changed that much in just 51 years, they should have been able to solve the cypher. It's shocking. Absolutely shocking. That they did not. /s

          1. Anonymous Coward
            Happy

            I suppose that with that many employees, and a computer being a computer, after all, whether in 1969 or 2020, the performances can't have changed that much in just 51 years, they should have been able to solve the cypher. It's shocking. Absolutely shocking. That they did not. /s

            Indeed. It seems a computationally cheap cipher to brute-force. The message is 340 characters long. That will fit into well under 1k of RAM. A major part of the brute force process was clocking through 650,000 permutations of it, which follow a logical sequence so don't need to be pre-generated, so little memory needed. If they tried each of 36 alphanumeric characters in turn for each character in each permutation, that would take about 8 billion byte operations.

            In 1969, that part of the brute force operation might take 64 hours on a 34,500 instructions per second System/360 mainframe system - ignoring the speed up due to it being a 32 bit computer, not an 8 bit one.

            That's a long time, so they might have preferred to use a CDC 7600, in 1971 these 60 bit machines ran at 37 million instructions per second. So, the same operation would have taken just 220 seconds. Not even time for a cup of coffee.

            Fast forward to 1979, and the same operation might take just over 2 hours even on a vastly cheaper 1 million instructions per second VAX 11/780 minicomputer.

            But then I forgot that the FBI give up on major crimes if they can't solve them within a week. /s

            1. werdsmith Silver badge

              I can’t imagine how Bletchley Park coped in the early 40s with their mechanical logic and flying tape readers.

          2. Cynic_999

            650000 is not such a huge number. If we assume that each permutation could be tested using 10000 computer instructions, then testing 650000 permutations would take about 2 hours per MIP (million instructions per second) of computing power. So even the early computers with sub-MHz clock speeds could do it in within a day or two.

      2. Tom 7

        "nobody had the means to test 650000 variations in anything resembling a human lifetime."

        And then along came covid...

    4. Anonymous Coward
      Anonymous Coward

      Re: Auguste Kerckhoffs

      The second principle is not that it will be - it is that it should be no less secure if the cryptosystems workings are made public.

      1. DavCrav

        Re: Auguste Kerckhoffs

        "The second principle is not that it will be - it is that it should be no less secure if the cryptosystems workings are made public."

        The idea behind this, of course, is that you cannot assume that the workings are not already known.

    5. a_yank_lurker

      Re: Auguste Kerckhoffs

      With enough time any cipher can be cracked by brute force methods. The only issue is how fast can one iterate through all the guesses before cracking the message. In 1970, it would only be cracked using a computer if the message was deemed important enough (e.g. Soviet diplomatic traffic). So SFPD was reduced to pen and paper and inspired guessing then. Decrypting the message in someone's lifetime, not very likely. Now, with much more powerful computers in your pocket than any 1970's super computer, brute force using a computer is more practical for anyone with a good understanding of cryptography and various methods used to hide the message. Now its more a matter of someone knowing enough to write code that can brute force the message and letting the box run for awhile.

      1. Anonymous Coward
        Black Helicopters

        Re: Auguste Kerckhoffs

        With enough time any cipher can be cracked by brute force methods. The only issue is how fast can one iterate through all the guesses before cracking the message. In 1970, it would only be cracked using a computer if the message was deemed important enough (e.g. Soviet diplomatic traffic).

        Computers were commonplace in the late 1960s. My local technical college was routinely running Fortran programs written by school children like myself on its already ancient IBM 1440 in 1972.

        But my main point is that messages can only be broken into by brute force methods if the attacker has some knowledge of the plaintext. In this case, the team correctly assumed that the plaintext was meaningful English language words or phrases, or possibly non-English that still used the Latin alphabet. This would not have worked if the message had been written in Phoenician.

        As a trivial example, consider a random ASCII character encrypted using a substitution code. The encrypted message is 01000100, i.e. "D". As there are only 256 possible plaintexts you don't need a computer to brute force it. Even so, you can never provide any information about the plaintext because you can never identify it. For the same reason, you could not successfully identify the plaintext by brute forcing an encrypted 100 digit random binary number, or for that matter, if it lacks any context, a numeric grid location in the Atlantic Ocean.

      2. werdsmith Silver badge

        Re: Auguste Kerckhoffs

        Bletchley.

    6. Michael Wojcik Silver badge

      Re: Auguste Kerckhoffs

      Kerckhoffs's principle, one of the tenets of modern cryptography, was demonstrated to be wrong here.

      It most certainly was not "demonstrated to be wrong". You don't understand Kerckhoff's Principle.

      The point of KP is that the key is the secret parameter to the cryptosystem. If parts of the system are (believed to be) secret, they become part of the key vector, in addition to the nominal key.

      And that's a poor contribution to the key vector, because they can't easily be administered, and generally the strength of the additional security is difficult to estimate accurately, because it has dependencies on the known parts of the cryptosystem, which reduce its effective entropy.

      The most economical and easiest-modeled contribution to the security of the system is additional key material chosen over a uniform distribution, forming a single homogeneous secret key. Anything else is sub-optimal.

      Had Zodiac (who probably knew little about cryptography) chosen a stronger but known system, with a longer key, the message would still resist decryption. But, of course, that wasn't Z's intent anyway; there's little point in sending a publicity-seeking message which can't ever be read and is indistinguishable from noise. Z was probably hoping the message would be decrypted within a year or so of receipt, when it was still current.

  5. Nick Ryan
    Terminator

    Disappointed

    There was ample opportunity to mention AI but all we have is here smart humans doing smart things. Such things cannot be allowed and must instead be mis-attributed so some form of magical unicorn fart AI system.

  6. John Smith 19 Gold badge
    Thumb Up

    Semi brute forced by three amateurs

    Impressive.

    Something to keep in mind for anyone who thinks they've built a better mouse trap of a crypto system.

    Sadly still says nothing much about the s**k f**k and where to find them.

    Could still be alive though.

    Maybe.

    1. Jellied Eel Silver badge

      Re: Semi brute forced by three amateurs

      Something to keep in mind for anyone who thinks they've built a better mouse trap of a crypto system.

      Yup, and also decryption system. From the looks of it, part could perhaps be optimised by dictionary lookups. Curious how 'machine learning' could be applied to spot the text to add to the crib, or realise ZK made some errors in their cyphertext. All part of the race between man & machine to see who's better at making sense out of patterns.

  7. a_yank_lurker

    Message Length

    One of the best ways to hinder cracking a message is to keep it short, though short is relative. Short messages will not always show the language's natural letter frequency thus removing one of the clues about the text. Great effort to crack the code even now.

    Unfortunately, I doubt Zodiac will be caught and tried. If he is still alive he would be at least about 80 years old now.

    1. Anonymous Coward
      Anonymous Coward

      Re: Message Length

      > One of the best ways to hinder cracking a message is to keep it short, though short is relative

      That is only correct if you state relative to what. Relative to your one-time pad, then yes.

  8. Imhotep

    Commonality

    Wasn't there another serial killer who also thought his victims would be his slaves?

    1. Anonymous Coward
      Anonymous Coward

      Re: Commonality

      Zodiac was possibly faking it for the insanity defence.

      He was smart enough to make a cipher that took fifty years to crack after all. While I think he was a psychopath, he clearly could function

      1. werdsmith Silver badge

        Re: Commonality

        He was not smart enough to realise that the message he sent to discredit somebody else claiming his work was encrypted beyond the capability of the law enforcement at the time. He most likely expected it to be cracked but wanted to make them work hard for it.

        1. Dave 126 Silver badge

          Re: Commonality

          He also made an error when encoding his message, skipping ahead and extra character when moving down a line.

          The fact that these ciphers are time consuming (by a human) to encode correctly is one if the reasons they are not widely used today.

      2. Michael Wojcik Silver badge

        Re: Commonality

        He was smart enough to make a cipher that took fifty years to crack

        He created a cipher that no one put enough work into to crack for 50 years. Or someone did, but didn't publish the fact. That's not a useful indicator of the design quality of a cryptosystem, and says very little about the capabilities of its "inventor" (a dubious title anyway, since Z doesn't appear to have used any concepts not already well-documented for pen-and-paper ciphers).

      3. Rob Daglish

        Re: Commonality

        I'm not sure Psychopath means what you think it does... DSM5 Criteria A.3 is "Impulsivity or failure to plan ahead.", which doesn't sound like someone who comes up with a cipher like that. Criminality isn't in DSM either, and only just makes it onto Hare's (2003) PCL-R.

  9. Throatwarbler Mangrove Silver badge
    Joke

    And here I was ...

    ... thinking it would be DRINK YOUR OVALTINE. 'tis the season, after all!

  10. Anonymous Coward
    Anonymous Coward

    So what was the method used to crack it?

    I apologise if it is mentioned in the article or the comments, but I have failed to spot it. I notice the link to YouTube, but I can't watch videos so that's no help.

    1. Anonymous Coward
      Anonymous Coward

      Re: So what was the method used to crack it?

      There is a description here: http://zodiackillerfacts.com/news-and-updates/breaking-news-the-zodiacs-340-cipher-has-been-solved/

      It appears to be a straightforward bigram substitution with the cyphertext rearranged in a non-conventional manner (diagonally rather than across).

      I'm sure this information would have been appreciated in the article.

  11. Anonymous Coward
    Anonymous Coward

    FBI confirmation

    They confirmed what? That someone claimed to have decoded the message or that the decoding was correct? In the second case, how did they know?

    1. StuartMcL

      Re: FBI confirmation

      That someone had developed an alogirithm or set of rules that extracted a meaningful and seemingly relevant plain text when applied to the original data

  12. Anonymous Coward
    Boffin

    Their next project...

    Orange Donald’s tweets.

    1. ortunk

      Re: Their next project...

      We have an HPC cluster on.it since forever, no coherence as of yet

      1. lglethal Silver badge
        Trollface

        Re: Their next project...

        but but... Cofveve!

  13. Grease Monkey Silver badge

    Stateside Jack

    Are we sure this was't work by the American equivalent of Wearside Jack? Certainly reads like one of his messages.

  14. tosgravely

    Ending

    The ending is jumbled. It makes much more sense to read it like this:

    I am not afraid because I know that my new life will be an easy one. Death is life in paradice.

  15. AJAY0618

    Not buying it

    I just don't believe this is a viable solution. There is poor grammar and of course spellings that were part of z480. The point is what they had to go through to decipher this doesn't seem to be the trouble Zodiac would even if to begin with to write it. It seems they fit it to me their needs. More objectivity is required here to accurately decode z340.

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