2012-11-17: Puzzle - First to solve wins

Posted at 2012-11-17 02:35:21 by SHD

For years I've had an idea in my head about a way to hide some information in a bunch of numbers. I actually got around to coding an implementation and figured I'd run a competition. The first person who figures out what the famous landmark is described by the second set of numbers below and posts the correct answer in the comments wins $100.

The hint

Here's a hint. The following numbers are a reference to the Eiffel tower:

7778457874
5651256228
6704779064
3038223708
5949959984
0366479924
9867779808
3948559064
4070829058
5834526088
9528989952
5320666502
6882068022
7469299991
9151111159
5882128204
9320093979
5289268474
9350097796
5581683024
5130298008
7330968804
5648215222
3847223428
2166128637
7663999663
5336232325
9758955998
2840222244
5147115746
5462994454
5796299729
9866282082
3583038580
7699199111
3663108038
9596057624
5462244788
3596210738
7426202503
3166415679
8433665999
1438675594
8144545414
0937014971
7144114974
7144941929
3554365403
1181115811
7437973694
8080910849
8338313788
9984490646
9728272998
0020330042
0736490682
0875010949
5489110698
8632422882
2048490788
9425004559
5243235555
7109819849
7469569567
3242772234
5149789084
9163071510
5449749729
7165278451
3144703308
7965821785
3219306782
8501804511
2043481782
9520070521
5827571585
2226626622
2721772761
6666680016
2226006281
7023230494
2450038914
4033850484
6463747392
1800250994
7444937494
7655957962
0338340383
3938338394
0326338204
6871308295
7831718394
6816343254
6479778768
6811743461
6835736685
6471564815
7417878788
0379330993
6291161116
9680615065
1421627605
9692727105
6412425069
9321657205
6745716745
2091051209
1131342123
2003225067
5500057005
6226855637
6199322434
6620729352
5870409656
6203051387
9709759337
2800402284
5527121375
5665565630
2525265452
1962468662
0861810860
6911661699
1170507715
2828552888
1161500566
1861526025
1971674470
1578573975
1821421815
3633753739
0710101570
9575070569
2323323231
2122713227
0265613577
6772001229
8247910237
9947276237
9502013271

The puzzle

Given the above hint, what famous landmark do the numbers below refer to?

2386126831
7225325327
9672997722
7447774673
8177777018
4178077328
7158326032
8950176323
0011977622
7042394616
7733989372
3334334683
2957779620
4280440827
9949552904
1821034922
1419372683
9691250370
4320735684
1554950900
5116791765
4266676462
7074171264
5585665458
5509990582
1301890762
3538960764
0916875258
2206671462
4993771463
1111813811
1844480441
2949994257
5337374335
3064317306
2695493417
4385314257
3908473805
4427613407
1525193459
2581727957
0169776079
3048343803
2260808226
6587178755
2540163274
3641318885
2588894260
6247839065
2568178904
8785050898
8236118331
1793771333
6790229729
7962597527
1793786352
8932051575
7786566709
8290000650
8700290542
7255153387
7168566062
5477219042
5010646981
3972219944
6602999062
6675666781
4994419947
4000113044
4666449362
9886698611
5778837585
2248582352
5801054108
1373773313
2683632611
9476374118
1065433508
5900493418
6596232311
5231998378
0611670763
9735142102
7285100083
9213925488
6281912898
7385687737
5731173130
9635666669
7213532231
5361521804
2387416392
5739565930
2787425879
2487503746
2331532325
2297325222
1786476677
5479974549
5387858388
9691611121
6700112054
3726112936
7937742083
5267013145
8989118928
1548545145
1311311133
3881613186
2052542051
4042483357
8855081321
6561333881
5822959889
5993453484
5885753887
4495883459
3453559320
9918169881
9338334984
9939971765
2121028925
5126095925
8983030378
7239967917
8161915166
7253457755
9826668929
2931013220
5439999433
6967444966
3144884848
2485055280
3262424202
7769191177
3262146253
7964472988
3485071865
2264161801
3227429449

Post the answer as a comment below. The first person to answer correctly with an acceptable explanation to how the answer was reached (rather than just a guess) wins $100, so make sure to use your correct e-mail address so I can contact you.

Note #1: People have noted that the numbers change whenever the page is reloaded. That's as expected. This puzzle is not an encryption as much as it is an obfuscation. That the numbers change is not important, as only the pattern in them will lead to the answer, which is of course constant.

Note #2: There was a bug in my post for a short while, which made the hint and puzzle basically the resolve to the same answer. This is fixed now. If you saved a copy the numbers before, just grab a fresh set.

Solved!

The second landmark was discovered by Batuhan Bozkurt, congratulations! The challenge has not yet been met entirely, though so I've decided to set a new challenge with the same method. The same $100 prize applies.

Redditor Bearasaurus has solved the final challenge too! For hints, check the followup post.

Tags:

Comments

Big Ben

Posted at 2012-11-19 09:55:28 by Colin Edward

I'm afraid Big Ben is not it. But be sure to include some explanation as to how the answer was reached, so I know it isn't just a random guess.

Posted at 2012-11-19 13:48:31 by Steven Don

I "solved" your puzzle, but I assume not in the way you wanted.

After giving it quite some hours, I failed to find any specific pattern (with a reasonable kolmogorov complexity) that would lead me to an answer. But in Reddit, you mentioned that you would be interested in statistical approaches that would lead to an answer (which I assume you are interested for increasing the security of the obfuscation?) so I exploited the fact that your website gives fresh batch of numbers at each reload so I grabbed about 1000 sets (with intervals in between, hopefully not causing trouble to your website, it handled the requests like a champ) and got to cracking.

Now your HTML formatting implies 10x10 blocks of data for each set. So that was a starting point when I first began looking at the problem. The grid is 70 x 20 so that implies 14 secret codes, 7 for each row.

I looked for what was common for each 10x10 block in each of the samples I gathered from your site. I found out that for each 10x10 block some digits occasionally never appears; for example in block 0x 0y, not all digits have to appear but one always appears at least once.

Once I looked at the remaining digits (that are common in all blocks at a particular coordinate), for the "hint", I was faced by these digits:

0485130
0021739

These are the coordinates in the form of degrees-minutes-seconds (dddmmss as you gave away generously in Reddit) of Eiffel Tower.

Once I ran the same process for the puzzle, the result was:

0295845
0310804

Which is the coordinates for the Great Pyramid of Giza.

Maybe this is disappointing, I don't know. If the website hadn't provided fresh batch of numbers, this method would not work. I assume, to strengthen the obfuscation, you could make sure one digit always appears at least once; but as long as the distribution isn't random, I suppose the answer could be extracted.

I've tried many approaches before this; I'm pretty confident that the pattern is not based on neighborhood relationships (as the answer can appear on edges, though wrapping around could be employed but still with it I failed to detect any patterns). I think it doesn't have anything (or much) to do with arithmetic on the digits (like summing / subtracting them). I tried various row/column patterns and couldn't come up with anything.

I also analyzed the 10x10 blocks containing the answer digits only once (so if the answer is 0 for that block, 0 appears only once in that block). But saw no obvious pattern at all. So this beats me in that regard.

If I am eligible for the prize for my answer, I would kindly ask you to donate it to the Doctors Without Borders foundation. If you are uncomfortable about it for some reason, you can choose to donate it somewhere else you see fit.

Thanks for the challenge, and although my curiosity has been partly satisfied, I'm still waiting for the answer that will allow me to solve this using a pen and paper using a single set of numbers.

Posted at 2012-11-19 16:36:10 by Batuhan Bozkurt

Batuhan, the answer is indeed correct. The Great Pyramid of Giza is the one I was looking for. The method you used is indeed not the one I was hoping for, as you haven't actually figured out the way the coordinates are encoded into the sets of numbers.

Still, I'm not one to dictate how the problem should be solved. I will make a donation to Doctors Without Borders for $100 in your name and post proof that I have done so.

Since I would very much like for somebody to solve the method, I'm including this static problem for a second attempt, and another $100. Being in a comment, the following set obviously does not change and encodes a third landmark.

2626513077384364666346599932245309032974209496921885110948315551555613
6549028370497764766953274173448611231555969009312435020244378244262894
9308377132331493394457637801172312372974892873367485438142538547446457
5987478672136633636156339295109196283474021313920015080695500005010510
9318473400638833698356337893287640679475088481921818727043921551931599
5758758671181690400516397336912974972974211231362065019596695870416497
1701226107698865022553554534544375771374969996927993180831110067651597
3203310324331357320447629709425333533533932743923435767555759732852649
0008077080336367751344339394399228589625005440340517458583553308156594
7467243472134765226056779555595344734475199118911888022882025906466417
0332300493776667648725560571112261196221231229957486429403779342535143
1366338577707417047142278890548676887286598087756091175002210326130060
5863902088494574497542911473583959753975898054668946115111760583633056
3673921092972792959782223331128568968982838265801286279605628360969080
5301986352763553665223261861393193111359891776463941295493449120391390
0463999640662807648743557375531417213379281451584481179187119326988940
4352555243298062697573961379660934698929891289118894828988929160129317
1871110111741174649945428445570098658283038728302510575750510526949009
3326333663020967498782260828822839081251556075505536114445618120357157
5602990599311067698721073220721651596922796029092045295295550390501233

The challenge now is to find the answer and a step by step description of how to extract the correct digits from it.

Posted at 2012-11-19 17:10:02 by Steven Don

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