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:

0934892349
0255352035
0075445077
9651515951
0675171770
9251183296
2655580623
0631329022
9674300783
0634462675
6474530643
1426077394
7376423503
2474095297
1336129755
7023535370
1476144777
2406424264
1310030033
5434444484
0115301303
9802908589
9285022808
8747074774
9850393850
9115900584
9787328678
9817992719
9204329890
0810953167
3722325337
8346285642
5258252018
1111191111
6659579256
8361475117
9036155147
6520662117
5183251616
5873029218
7264157203
1531180098
7234467126
2536021762
8264762710
7616171667
2704727602
7061171660
1234243231
8535008500
5456655346
4213111412
5660586450
1202110032
8353535348
0493455352
7690116312
9318486442
4823980449
4795335342
2254420558
2789481093
5353448596
2702412799
5700382420
9380339330
2706440264
4703230874
2204542052
5752275255
8659913265
7066657519
1819920314
7831101504
7039160783
7353115565
5319115131
8889688888
1060919161
7636776667
5156140585
0012434984
5035090785
8515911525
6818430523
3388338185
0266260526
7170270724
4494344903
7877711187
4166262661
4298799793
1083711177
3341888311
7033777777
3091728448
4338795797
1033385452
3393827942
1346728558
0202553099
8065566424
7602059090
2481868068
7150053699
6999559568
3444323474
0033305030
6668667629
6464626499
4678426163
2633048647
2355010167
9976046631
1321418163
3641316341
1231424121
7606646087
6328628663
8070770806
6123192482
2241534484
8403833482
3065234380
2481097982
9200932090
8592963952
8785597584
2824844482
2332234283
0221163123
0454445204
4544772454
2370723707
8517571588
3637273287
6978275504
2833673208
9306073474
0583763153

The puzzle

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

7188761869
8584844086
0038170364
8184436700
8081722667
0368778030
0021100101
8189899899
3584432844
7118018110
9271992718
4448494841
0038000683
5557352733
2436113648
2870690743
2749000643
8668792688
8329212843
2925697843
0029299121
4939615817
5101939696
9695129526
2275238827
3998313897
6858858628
6999599586
3336335163
2559859811
4264418576
2181406622
2800669183
3869335746
4801166632
3133133313
2281929218
1767337567
6800400000
4109609660
1701200112
4711844778
3927192772
0537953529
5068118080
5917903463
8908231885
5017166814
5531242029
5727973670
8105150108
7477667774
3583838883
8752973878
7180998979
3483107033
7557684775
7720664138
8772676589
3585865675
1439949811
7798798017
1177475421
3090090300
1181991681
0257475001
2369695817
9077949611
5352973321
0588399327
3132011213
4537457359
3178417443
2002525552
2292999299
3202566644
3538181420
3178523611
2232995818
3207087051
4530482639
3402010135
5421626668
3821876479
9062616165
4478776468
7592112175
6662220669
0077476430
9766968379
0195339015
1005010000
6606060066
0937111149
8576156586
0575165610
7695143416
8696101238
0506385938
0175384181
0505079650
2008002348
4383141318
1414646914
0010390903
8756490358
4518902600
8706092008
3328340954
7254199358
6611616116
5978488404
0284042428
4205554545
8497774477
5487525192
5904768318
4278655887
4211043425
5917158388
1760329691
2299755475
3517560217
8909307265
2226258477
5502555270
4660409467
0151220715
4869768497
0076227051
9990077854
4053978854
1920467449
7493478257
0895273444
4779977449
4786878644
9935323859
7535277235
7145767554

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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