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December 20, 2005
Rotor 2 wiring
Here it is:
18, 23, 35, 16, 28, 3, 13, 26, 14, 22, 19, 32, 15, 0, 2, 20, 10, 4, 27, 7, 21, 24, 9, 5, 12, 29, 33, 31, 25, 1, 17, 8, 11, 34, 6, 30
Same conventions as before. How many did you get right from the diagram?
Posted by Harry at December 20, 2005 07:09 PM
Comments
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Kati,
The way we made sure that our program had the rotors going the correct way was to build the pringle machine, give it an inital setting (e.g. 1,2,3 we decided would mean Rotor1 -> turn one step clockwise i.e. away from keyboard, Rotor2 -> turn 2 steps anticlockwise i.e. towards the keyboard, Reflector -> 3 steps clockwise. We decided that we'd put ourselves in the position of the character going through the machine...clockwise would always be from the point of view of the character.
We then manual put 2 chars through the Pringle machine and traced its value at every point in the machine. We did the same with any program (just loads of print commands).
Where our program did not agree with the Pringle machine meant we had something wrong.
So, see if your program disagrees with the Pringle machine. It was a pain making the Pringle machine but it turned out to be well worth the effort.
Eleven1
Posted by: eleven1 at December 29, 2005 03:30 PM
Kati,
Reflect your reflector (or do your pin settings for the reflector picture in the Pringle pdf file anticlockwise instead of clockwise).
Your program will then work (I suspect)
Eleven1
Posted by: eleven1 at December 29, 2005 11:49 AM
[I'm not sure. Try reversing the rotor directions. Make sure they are going in opposite directions as well. Are you brute forcing the intial position of both rotors? Harry]
No, I've made one assumption, which is that the initial position of rot1 was laziness by the cipher clerk. Apart from that, I will have a look at tweaking the rotor directions - thanks ;)
Kati
Posted by: Katriel Cohn-Gordon at December 29, 2005 11:20 AM
Is a Pringle machine supposed to be a mechanical device for encrypting/decrypting or a model to help us make a computer program?
My Pringles were yummy but now they're sitting on my desk cos I don't know quite what to do with them.
[Either. It's probably worth building it and tyring to use it to give you a clearer idea of how these rotor machines work. Harry]
Posted by: cecil at December 29, 2005 06:49 AM
Harry
Was it intentional to have the picture of the reflector on the Pringle Machine instructions back to front?
We assumed that this picture would be correct(our fault for not checking) as it was provided with instructions for how to place it on the end of the pringle lid...facing outwards. In fact if you place it outwards it does not work.
Never mind, we are better codebreakers for the experience...if you bang your head against even a brick wall for long enough...it falls down (mainly cause it only seems to be a brick wall :-) )
Thanks again
eleven1
Posted by: eleven1 at December 28, 2005 08:54 PM
Well done eleven1!
Posted by: Jess at December 28, 2005 07:46 PM
Harry
Finally...we've done it...and it was the most simpy thing ever...we initially had a bug in our code...so we built a "Pringle Machine" and modified our program to match it...Unfortunately we had used the wrong version of the Reflector picture i.e.we had it back to front!
Oh well, now we've got a better, more flexible, program that can handle the rotors being placed in any order and reversed.
Thanks to the person who posted about the picture of the reflector...we'd read this post many times without realising its significance to our problem.
What a great challange...now we can relax and enjoy the rest of the holiday! :-)
Posted by: eleven1 at December 28, 2005 03:30 PM
I have the same problem as eleven...I have a working en/decipher program but I've run the brute force (all possible rotor1+rotor2+reflector) several times and it still comes up with nothing. The brute force subroutine does work though as it will crack my own messages easily. Is there something trivial I'm missing, e.g. a setting?
Thanks, Kati
[I'm not sure. Try reversing the rotor directions. Make sure they are going in opposite directions as well. Are you brute forcing the intial position of both rotors? Harry]
Posted by: Katriel Cohn-Gordon at December 28, 2005 02:57 PM
Harry, is the deadline for Challenge 8 really 23.59 on 5th January? That's a Thursday, and I thought that it was usually on a Wednesday- or is it different because it's the last one?
[It really is on the Thursday because it is the last one. How are you doing? Harry]
Posted by: Jess at December 28, 2005 08:37 AM
Harry,
We are getting more confused...can you tell us if the Pringle Wiring is supposed to tell us that, for example, an 'A' maps to a 'P' (Rotor1) on the actual "Fialka" being used or it just showing the wiring maze and we still need to work out how the maze has been inserted into the rotor?
[Should be the actual wiring. Harry]
Posted by: eleven1 at December 27, 2005 03:39 PM
Harry,
Thanks for the help. We had guessed that the 36, 15 and -35 were something to do with the initial settings of the rotors - we started by trying these settings (in various combinations) for our rotors and then trying every possible starting point for the reflector. Unfortunately we had no joy. We then resorted to brute force. I guess we've got something else wrong in our program setup. The program will encode and correctly decode any given message. It accepts input settings for Right Rotor (nearest punchcard), Left Rotor and the reflector.
We have placed the rotors with their zeros aligned
(is this correct??? - we do not think it should make any difference to our brute force attack) and then we make them turn to match the input parameters (nos 0 - 35). We have the Right Rotor moving away from the keyboard and the left rotor towards the keyboard.
Our brute force tries EVERY combination of offsets for the rotors and the reflector.
We feel we have missed something VERY trivial as our program seems to work for coding and decoding our own messages.
Can you see where we've set it up incorrectly?
Eleven1 - we are going to crack this today it it kills us! :-)
Posted by: eleven1 at December 27, 2005 11:17 AM
OK, we still need help...
We think our program tries 8 different configurations for the 2 rotors i.e. choose which rotor is on the left (next to the reflector), choose which way round it is, now choose which way round the other rotor will go.
We've tried "intelligent" guessing at crib words in the message, we've tried brute forcing it (looking for obvious word).
Still no luck.
In desperation we've made a "Pringle Machine". Our program seems to work i.e. we can set the Pringle's rotors to a known config and encode some letters (including rotation of the rotors as specified) and our program correctly predicts the endoded text.
So...what arer we missing. Of course our program might be wrong but we are starting to think we have not fully understood all the setup possibilities of the "Fialka".
Any hints would be greatly appreciated!
Eleven1 (on a Xmas break!!! Not :-(
[Are you getting gibberish from the start? If so you need to figure out what position the two rotors are in when the machine is set up. The code breakers at Bletchley used to try and make an intelligent guess about how the machine would be set up based on other intelligence. One way is to imagine the operator is lazy or careless and is using a setting written down. Perhaps one of the numbers on the weather report was used at least for the initial setting of the fast rotor? Harry]
Posted by: eleven1 at December 27, 2005 10:12 AM
yeah, hard problem .......
Posted by: martyn compton at December 26, 2005 11:22 PM
Just a suggestion harry, for next year is it possible to set it up so that when you go to get the challenge, you have to sign in and then your timed from that point onwards, it would stop people from having to lose points because of other commitments etc.
[This was suggested before, but it would be hard to stop people cheating by getting the challenge early (using a fake id or from a friend). Harry]
Posted by: martyn compton at December 25, 2005 12:16 PM
It is probably a bit early to think about the challenge next year, but I have a question! Do you think, Harry, that this year's system of having time bands in which to submit answers to score points will stay, or will you trust people not to crash the server with rapid multiple entries and go back to the old system from 2004?
[I think it will probably stay. It has two extra advantages. First people with awkward time commitments (school buses to catch etc.) are not so disadvantaged, and the competition is more exciting in the later stages. Harry]
Posted by: Lizzy at December 24, 2005 09:46 PM
Warning to all Pringle can solvers.
Following Harry's instructions I found that the pins on the punchcard and rotors were going in the opposite direction to the pins on the reflector. In order to solve this problem the picture of the reflector Harry gives you needed to be reflected(I used the mirror function in paint shop pro)!! Now the pringle solver works. Maybe this was because I made a mistake somewhere else in the construction!
Merry Christmas.
[I think the point is it depends which way round you stick it on the can! If you stick it face out you need one of the reflector pictures, and if you stick it face in you need its mirror image. Harry]
Posted by: nick at December 24, 2005 11:47 AM
I'm finding the website very slow as well
Posted by: Mark at December 24, 2005 11:34 AM
Jessica, i don't think its your connection. its happening with me too. the website's sooooooooo slow, Harry. is something wrong? can you check it out please?!
[I checked it, our network connection is broken and there is nothing I can do now everyone is on leave until after Christmas. Sorry. Harry]
Posted by: lara at December 24, 2005 11:23 AM
Harry, the website is being very very very slow, pages are taking absolutely ages to load and sometimes the connection times out. Is it your server, or my connection? Other web pages seem fine.
Posted by: Jessica at December 24, 2005 08:26 AM
Harry,
We've now tried our program against all the configs of the rotors and reflector that we can think of - no luck! We must have a error somewhere in our program. So it looks like we will have to wait until you release another hint....WHEN?????
Thanks
eleven1
Posted by: eleven1 at December 23, 2005 06:54 PM
i havent even looked at it for a week :P its too near christmas to be cracking codes.
merry christmas eve eve, everyone!!!
chidders
Posted by: chidders at December 23, 2005 04:43 PM
could anyone please, please, please tell me what rotors are and how they work?
Posted by: lara at December 23, 2005 02:20 PM
Will the comments section of the website be closed over Christmas?
[No, but I may be very slow to moderate/post comments and/or reply to them. Harry]
Posted by: cecil at December 23, 2005 01:58 PM
bought my pringles (yum yum!) what do I do now? why did I leave it so late to start??? I really think Pringles should give you a kick back after all the publicity you've done for them. Merry Christmas/Hannukah/Holidays/Winter/whatever else and a Happy New (Gregorian) Year!
Posted by: cecil at December 23, 2005 12:22 PM
Anyone got any ideas if a rotor machine can be broken without brute forcing? I ended up brute forcing all the settings, but I think that's a little primative, and would prefer to have done it in a nicer way by solving some calculations. The best I can think of is to find a crib, and then find what settings would convert the plaintext character to the ciphertext character, but that's still basically brute forcing it!
Posted by: Tony at December 23, 2005 12:21 PM
Ocelot,
You also need to work out where the fast rotor turns over the slow one.
[That is the point about the wiring maze too. Harry]
Posted by: Sir Solvalot at December 23, 2005 09:05 AM
Did you do last year's challenge? Did you make a program for 8B? Does it work? Can it run without positioning of both jokers? Could you solve last year's without a single hint? If so, you should try Challenge J1, the instructions and all required info (except about the cipher algorithm itself which you already know about) being on the Music Maestro thread. If you're program isn't good enough you could try making it better in any way you can. Or you could try it by hand to get the feel of things...
I shall say that you do not need to test every possible card combination. This is because it is a stream cipher, and not all cards are used on the first letter, only a certain few. I'll leave that there for now. It is a very important point, and I think key to breaking the cipher.
First hint for Challenge J1:
The first word is: ENCRYPTION
That may be obvious, but it's better to know for definite.
Have you tried it yet, Harry? Or should the question be, has anyone? It's open to all this challenge. There may be no prizes, but that shouldn't make any difference.
Posted by: Jason at December 22, 2005 08:23 PM
Woo hoo I finished...
If you're struggling, keep going! It might seem impossible but if you get a tiny handhold, grab it and go. It is so satisfying after 2 weeks solid work to hve done it.
Good Luck!
Posted by: Josh at December 22, 2005 04:46 PM
Many more correct entries?
[Fifteen altogether. Harry]
Posted by: Tony at December 22, 2005 02:55 PM
the fairham crypto geeks are having a pringle party in Nottingham on tues jan 3rd from 1000-1400. Anyone else want to join us?
Posted by: janet at December 22, 2005 02:46 PM
Are Pringles sponsoring you for this?
[I wish. Harry]
Posted by: cecil at December 22, 2005 07:41 AM
i have made a pringle enigma machine
[Excellent, now you need to figure out a crib. Harry]
Posted by: freaks at December 21, 2005 09:48 PM
I would just like to wish everyone a merry christmas and a happy new year!
...cameron...
Posted by: Cameron McHenry at December 21, 2005 03:13 PM
It was one of my 192 possible permuations :p
How many solvers Harry?
[Fourteen! Harry]
Posted by: Jonathan at December 21, 2005 02:38 PM
Is at least 1 of the photos of the rotors the wrong way round?
[Could be;) Harry]
Posted by: Mark at December 21, 2005 12:53 PM
ok ive got both the rotors right, but my program still comes up with some mistakes, could you tell me what the punchcard should be, in the same format as you've given rotors 1 and 2
Posted by: Captain Cool at December 20, 2005 09:30 PM
Are the three remaining variables the order of the rotors, their and the reflectors starting position, and the rotors' orientation?
[That's right. Harry]
Posted by: OcelotIIX at December 20, 2005 09:25 PM
heeelp can you tell me how to start deciphering the cipher pleeease
[Have you made a Pringle Enigma machine? Or do you want to try and programme it? Harry]
Posted by: freaks at December 20, 2005 08:12 PM
harry can u tell me where the wirings for rotor one r as i havent found the PDF file yet
[The wiring is listed in an entry on the log. Harry]
Posted by: freaks at December 20, 2005 08:11 PM
Hmmm, wasn't too bad, only got 9 wrong, but i guess it makes the difference, setting my program running now...
Posted by: Josh at December 20, 2005 07:35 PM