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:

1431651436
3105515230
8657184716
0762226570
6677337336
2109615470
2954337336
3503610216
1982537736
5144787236
5858472188
8585558600
4740952265
4038860260
3556890660
1075775601
6202692606
0716160167
6828888268
2295250280
2217552388
0155305628
5456667762
8276102829
6633017762
3600550625
8882882282
7502005702
7699367369
1883615368
8395855713
0140564027
1775078225
7530724053
8909454055
5159555015
2228728277
8775558753
2420564025
1216611126
5055555033
4044000464
0919391930
5103306132
7224773422
5206690132
5949176434
9851450463
4587451133
1008700936
2014101937
7721424597
2027388223
5014465235
6269122134
2067372736
4511114161
7123442427
6289622888
4704848074
2533868594
4303558229
0717968234
7882451227
3041499247
7525151227
4822598254
6211469241
5397954379
6234424593
1616310232
8529831278
8640515225
8724886480
1649705284
8684779747
6326882622
3619816896
1746541545
8540004004
5534339534
7767764775
2332213298
7793999377
1676776964
1118899375
0104744998
4848039537
6601516975
9743116974
9666976897
6314437426
6060076000
7565556857
7075575570
3805236850
8297976097
2730276470
9523576855
0959977877
1018264191
1598007661
4608524877
1398580825
4098982052
0578558058
4678778780
4018040018
4309993039
1198819988
9405449505
8898012800
7555555567
1244112404
5388558834
3593218530
4049852804
1659815560
0773354860
3908358804
3476321330
3476868471
3622312535
3672481679
0670585998
0552550255
6476366766
9676886896
3402430044
8600300396
6328716806
5794393116
2609873118
8503983114
8735217146
3316313416
2331823828
4441487114
1411112141
1900096106

The puzzle

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

9602800928
8829770279
2894888899
8170681677
2436773776
2404745079
9620732334
2839891170
8640750119
9636847872
1515995221
5647837468
9251951912
3200053020
5225556562
1800295262
9020655960
2166796220
2355331828
8708853022
3992358571
1587088800
8109056411
9334868971
1303057870
9649996478
7947667987
9959558905
8788188871
7076696710
3714545845
8699334385
3099111355
6777374193
6754705217
6704770478
3099339330
3619369131
9757888787
8673163167
8645780850
8515408502
0565775083
0804760573
8544760980
4832738884
0514251280
8575777787
8542452248
8609209998
5555445255
4880104681
0940949930
2192711722
5222315203
9151211903
0262519222
2448901209
9419945732
6466045983
3999870379
5435276430
2675680430
1453410411
3089870430
7799776389
1311130712
3133118434
8000080478
7187770610
1890906200
0990289742
0635215131
0995156226
0505943927
3050113335
0900339006
1635226556
8599229999
0630900099
6639690663
7005002058
0181111008
5001056107
3241531254
3820651057
8562892104
6347731057
8983892607
3444109003
4890653352
0638163906
8744123702
0143153816
9613653042
3230353302
3502423046
2748726748
6559353916
6051161052
4544226944
9494985949
1574714750
8913789173
5955555597
5064615194
4568314973
7022525771
9191785147
2139885749
5677577655
2983828389
6839288693
2359637253
7968177619
6987540741
6968198456
6973665885
2872618231
5933878118
7747488747
1530590105
0666686680
9799040987
5111751736
4163050705
9178380137
5006886105
1406480780
1100071980
7578595634
0455945638
7435299651
0387795838
5806499634
1101919031
3939899938
7995597858
3722925937
4274175614

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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