back to article National Museum of Computing to hold live Enigma code-breaking demo with a Bombe

The National Museum of Computing (TNMOC) is going to fire up its replica Enigma code-breaker to decrypt encoded messages sent from Poland – with an original wartime Bombe operator supervising the process. The British museum's Bombe replica, recently moved into the original Block H building that housed the wartime Bombes, is a …

  1. Androgynous Cow Herd


    1. werdsmith Silver badge

      Well I established it's not a linear ROT.

      That's as far as I'm going. With 3 or reels, a reflector choice and a steckerboard I'm not going to get there.

    2. Scott Broukell

      Message Reads -

      Send three and fourpence we are going to a dance <message ends>

      1. werdsmith Silver badge

        Re: Message Reads -

        No, we don't need the message. We need today's reel choice, settings, plugboard etc !

        1. Lee D Silver badge

          Re: Message Reads -

          What phrase is in every message? Heil-bloody-Hitler!

          (P.S. Great movie and I don't care whether it's inaccurate).

  2. monty75

    Cool. I wasn't planning on doing too much work on Friday anyway.

    1. JCitizen Bronze badge

      It will be great!

      I would literally fly to the UK just to watch that! They did a pretty good job simulating it in the movie about Turing. Too bad I'm too disabled to go!

  3. Kubla Cant Silver badge

    While the machine does its work, participants in the conference will hear papers

    If they're in the same room they may struggle to hear the papers,

    1. hplasm

      ...participants in the conference will hear papers...

      Rustle rustle...


    2. Anonymous Coward Silver badge

      From TFA:

      "As part of the World Computer Congress being held in Poland"

      The participants in the conference will be in a different country. The bombe is noisy, but not THAT noisy!

  4. Will Godfrey Silver badge

    Good stuff

    And while TNMOC is steadily expanding, the rest of Bletchley Park is turning into an over-priced send rate theme park!

    1. Steve Davies 3 Silver badge

      Re: TNMOC

      is also totally self funding. It deserves all the support from the IT Community it can get.

      I've been a member for a number of years.

  5. Yet Another Anonymous coward Silver badge

    An original message?

    Will GDPR apply?

    Do we need to get permission from the original sender?

  6. YAAC

    Block H didn’t house any Bombe machines. It was erected between May and September 1944 to house Colossus 5 to 9. It therefore qualifies as the first purpose built computer centre.

    A viewing of the Bombe replica, a truly monumental undertaking, is the perfect accompaniment to Colossus, Heath Robinson and the Tunny machine rebuilds Then take in the rest of TNMOC, best done on one of the public tours.

  7. casinowilhelm

    "The electro-mechanical computers were used to read military messages sent between high-ranking German commanders"

    The enigma was more for general communication. The really high ranking officers used the lorenz machine, a completely different system (see colosssus, etc)

    1. Richard51

      Even worse, the bombes only generated possible settings for the Enigma machines, they were not infrequently wrong. The decryption was done on British made improvements of the Enigmas.

      p.s. the bombes were improved versions of the Polish bombas, not an invention in their own right,

  8. GrumpyKiwi

    France contributed too

    The French were also involved in the initial work to crack Enigma, assisting the Poles. And the Poles who fled after the German invasion went to France first to continue their work.

    When France fell, the French first passed on all their work to date to the UK and then (even more importantly) never once let on to the Germans that their systems were vulnerable to compromise.

  9. FrankAlphaXII
    Thumb Up

    Good deal. Hope it works well.

    Very cool. If it wasn't in the middle of the night here I'd definitely be checking it out. Hopefully they'll make a recording available.

    Now as cool as this is, what would be even more impressive is a demonstration of the SIGSALY, which was the first encrypted telex and telephone system that Roosevelt and Churchill used to communicate with the WWII equivalents to the modern Unified Commands during the war, but it would take some doing to get it to work for an actual demonstration. It was a fairly touchy system even when it was being used all the time.

    NSA still has the one that was installed at the Pentagon at the National Cryptographic Museum (I've seen it but I'm not sure if it works, its not powered on) and I'm not entirely sure if that's the only machine left in existence, it very well might be because I can't find anything clear about what happened to the one that was at Selfridges in their sub-basement. I'm assuming that GCHQ, the Australian Signals Directorate, or even the TNMOC might have one somewhere, there were like 12 of them by the end of the war, but I can't confirm where any of them besides the one at NSA wound up.

    Searching for the term SIGSALY on the TNMOC webpage doesn't return anything, the Crypto Museum organization's rather good article on the system doesn't say what happened to the actual hardware and NSA's public facing article on SIGSALY doesn't specify either.

  10. Winkypop Silver badge
    Thumb Up

    Support the TNMOC

    It's no secret that it's a very very cool institution.

    The place is amazing in all of it's dusty and electro-mechanical complexity!

    The most memorable thing for me was the *smell* of the old equipment.

    Glowing valves, reminds me of TV as a kid.

    1. DropBear

      Re: Support the TNMOC

      Back then you had to wait for the TV set to "boot"; then later TVs just turned on instantly. Now you have to wait for them to boot again... We clearly have come full circle...

      1. Lotaresco Silver badge

        Re: Support the TNMOC

        'Back then you had to wait for the TV set to "boot";'

        Heavens no. Your CRT TV did not boot. Like all thermionic valve equipment of the era (RADAR, Radio, Mine detectors etc) it had to "warm up" before it could be used. Which was important for Colossus which had to be kept running 24/7 both to be ready to use when needed and also to improve reliability because components weren't subject to variable thermal loading.

        1. DropBear

          Re: Support the TNMOC

          Heavens no. Your CRT TV did not boot

          *sigh* okay... we need to establish here if you really think I'm a simpleton dense enough to actually think those old TVs I am apparently old enough to have witnessed in person needed to literally "boot", as in "run code until they're ready to show the picture". Because if you do not - do you think you might just possibly lend me the artistic license to call "booting" (already in quotes in the original, very much on purpose) the fairly lengthy process of having to wait between pressing the button and getting to see the picture...?

          I probably still have somewhere the channel selector of our old valve-based TV - it had two amplifier valves in shielded cans you could unscrew right on top of the selector drum, which was full of small PCBs housing tunable inductors, switched in and out of circuit through a comb of contacts. I KNOW how valve-based TVs worked, thank you very much. My dad and I have fixed ours a few times, until the CRT filament went open circuit and there was nothing left to fix. Thank you for taking an interest in my comment. And no, I'm not going to start choosing my words more carefully just because some apparently take pride in nitpicking everything that isn't 100% nailed down to mean one and only one thing.

          1. Lotaresco Silver badge

            Re: Support the TNMOC

            " we need to establish here if you really think I'm a simpleton"

            Oh we really don't need to establish it.

  11. This post has been deleted by its author

    1. Jedit
      Thumb Down

      "Perhaps I'm being cynical"

      Yes, you are. And also massively disrespectful.

      On a related note: does anyone have any evidence for or against the old claim that a skilled abacus operator can produce results faster than someone using a handheld calculator?

      1. Alfred

        Evidence for Skilled Abacus Operator being faster than someone with a calculator

        "does anyone have any evidence for or against the old claim that a skilled abacus operator can produce results faster than someone using a handheld calculator?"

        I'm glad you specified "skilled abacus operator" rather than specifying operating on an actual abacus.

        The very skilled abacus operators don't even the abacus; they begin with the physical abacus, but as they progress they use a model of one inside their head to do the calculation, instead of having to accept the delay of physically manipulating a real abacus.

        Here's a skilled abacus operator (not using an actual abacus - that'd be too slow!) summing 10 four digit numbers in three seconds:

        Here's a Guardian piece on the championships. 15 three digit numbers flashed up in 1.70 seconds , and the skilled abacus operator summed them.

    2. Anonymous Coward Silver badge

      If you'd ever watched someone performing a reasonably complex calculation on an abacus, you'd realise that it's actually quite interesting.

      It's amazing to realise what can be achieved with simple technology.

    3. Dominic Shields

      Hmm, but was your kit available in 1939?

    4. a_builder

      I used to play chess with one the Bletchley code breakers, John Herivel, as a kid.

      Very nice unassuming guy. Mind as sharp as a razor.

      I think you underestimate how clever what they did was given how limited what they had access to was and how they had to determine everything from first principles. Yes, by modern standards the Bombe has an excruciatingly slow clock pulse (the incrementation is essentially a clock pulse) but back then it was incredible. And incredibly fast.

      Yes, the Bombe only ever narrowed the solution set down but combined with say the Herivel tip and the elimination of various solutions that were not possible it gave a narrow range of possibilities that could be tested within a timeframe that made the intel useful at that time.

      What these guys did with what they had to hand, very often pencil and paper and their brains, is quite incredible.

      I salute them and wish I had their tenacity and insights.

      1. Lotaresco Silver badge

        "I used to play chess with one the Bletchley code breakers, John Herivel, as a kid."

        The headmaster at my grammar school was a former Bletchley code breaker. Sadly he was a bullying martinet with a short fuse. I respect what he achieved, not what he was.

  12. Citizen99

    Editorial @ElReg

    Not Block H for the Enigma message demo. Also see YAAC's posting above and others.

    We visited Bletchley Park the day before yesterday (18 Sep 2018). In Block H were the 'Heath Robinson' and 'Colossus' re-builds, the machines that were used against the 'Tunny' high-level traffic. No sign of any 'Bombe', the machines thet were used to crack the 'tactical' level Enigma traffic. The National Museum Of Computing room was closed; peering through the glass window in the door we couldn't see past the more modern stuff to see if any Bombe was lurking in there.

    1. Andy Taylor

      Re: Editorial @ElReg

      I can assure you that the Bombe rebuild is currently housed in Block H. There's even evidence here:

  13. Anonymous Coward
    Anonymous Coward


    Seems that some of the valves for Colossus Mark 0 were hand selected using a resonant step up technique involving a kitchen scourer and voltmeter to rapidly sort through them so that critical timing related parameters could be matched.

    Wonder what other "goodies" we aren't aware of because of the Official Secrets Act 1949 ? seems that some of the records are sealed even now until (IIRC) 2024.

    1. bombastic bob Silver badge

      Re: Random

      by the time 2024 rolls around, there won't be a whole lot of engineers out there that understand vacuum tubes [aka 'valves'] very well, at least not well enough to appreciate the process of trying to rapidly determine matched sets from a pile of contenders. Well, maybe some guitar amp and tube-audio enthusiasts might, but that's about it.

      Also have to appreciate the level of hacking done back then, because the war demanded results, NOW, and there was no time to waste.

      1. Anonymous Coward
        Anonymous Coward

        Re: Random

        I only found out about it due to some elderly amateur radio enthusiasts discussing a similar method being used to match tubes on output stages, but couldn't understand at the time why it would help. Later worked out that valves that didn't make the grade got sold on at a lower price rather than simply destroyed to disguise what they were doing with them.

        Seems that agents visited literally every supplier in the UK rounding up and testing specific tubes they thought might be useful, the people doing the testing didn't know why though. As heaters were never fully powered it didn't stress the tubes.

        Classic example of compartmentalization!

        Seems that Tektronix did something similar but they would buy a lot of specific parts then test them for the exact values and thermal profile needed. Laser trimming of resistors wasn't invented until much later.

  14. Stevie Silver badge


    Shame. If they'd decided to start around 1:30pm I'd be able to watch without getting up in the middle of the night - not gonna happen.

    Of course, it being a Friday the start would be more like 3pm and no-one would be at their peak, decrypting-wise.

  15. a_yank_lurker Silver badge

    Enigma Flaw

    There was an interesting flaw in the Enigma machine that reduced the complexity of the code a little. It would never map a letter to itself. Plaintext "A" would never be mapped to "A" in the cypher. Also, there were numerous 'cribs' developed to help in figuring out the daily solutions that sped up the process. The real genius was the application of math to understand how even try to break the code and thus design and build the bombes and later Colossus.

    1. Yet Another Anonymous coward Silver badge

      Re: Enigma Flaw

      I always wondered if this was enough of a flaw to make the system breakable?

      From all the accounts I have read, and the talks by the people who used it, it was failures in OPSEC that led to the breaks. Picking the same daily 6 letter groups, re-sending the same message with the same settings, sending identical weather daily reports by both Enigma and easily cracked simple codes etc,

      Anyone know of a modern cryptanalysis of the Enigma?

      1. Andrew3456

        Re: Enigma Flaw

        Hi you will find the following paper very interesting in this regard, talks a lot about deciphering of authentic WW2 messages!

        I read the James Gillogly paper years back (anyone have a link?) when the Simon Singh cipher challenge

        was going on, even wrote a small program to decode the challenge example myself. Appears since then

        some great improvements have been made to Jame's method.

      2. a_builder

        Re: Enigma Flaw

        It is absolutely true that A could never be A etc in Enigma which did reduce the solution set of itself.

        Also combined with

        - Herival tip - reduced range of rotor settings - only started to be off use later in the war - essentially laziness (human nature) in changing the settings

        Gardening - doing something that would be reported by two systems such as dropping mines obtrusively where the other reporting channel was penetrated

        Weather book - weather report origins could be triangulated and the weather known and this was often reported by two codes one of which was penetrated. This was the early door in but was shut.

        -The bits that are still classified probably do relate to OPSEC insights as well as how the physical data was interpreted to provide cribs. As well as traffic analysis which is really the untold story that will probably never be fully told as all those who really understood that are now gone and the records from that period are hardly garrulous.

        John [Herivel] was always of the view that the Enigma secret should never have been told. He would never say why he was of that view. All codes are breakable, so that cannot be the reason, but my guess was that it was rather the raft of ingenuity around taking peripheral data and using that to penetrate the encryption was really the great secret. Personally, and I have no special insight into this, I think it is the maths behind the OPSEC and traffic analysis that probably a greater secret than cracking Enigma.

  16. Anonymous Coward
    Anonymous Coward

    RE. Re. Enigma Flaw

    Yes I think there are C# and JVM implementations now.

    Someone even wrote one that runs on a Pi, though more of them means faster decryption.

    Actually better off using a graphics card as even one from maybe 4 yeara ago with a few running repairs would do fine.

    Interesting anecdote *2, an AI fed random encrypted messages decoded them much faster than with conventional dictionary/crib/etc searches by brute force.

    Random idea: use a network of Pi on a DIY backplane.

  17. Anonymous Coward
    Anonymous Coward

    Please stop referring to Alan Turing as a code breaker. He assisted with the construction of some machines to assist the code breakers, he himself didn’t break codes.

    Also it would be nice to credit the Poles who originally designed the Bombes – Brexit is one thing, but it doesn’t mean we have to go down the path of ignoring the contributions of our allies.

    1. steviebuk Silver badge

      They are credited in the article.

  18. Criggie

    Can't believe noone's said it already....

    "someone set up us the bombe" ?

  19. steviebuk Silver badge

    It's on YouTube

    But please tell me they recorded the code breaking part. The live feed is going and not giving an option to rewind :(

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