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:

1013108311
4141431432
2121222116
4303860385
0906339060
0853631310
6009902460
0404920422
9110831485
1064431431
4003222040
2542425242
5002505620
2565772752
4450554540
2562728189
2063559296
5502738598
2032556457
4403546253
7343777436
8668867864
4424444078
4736447363
4656556454
7968876054
3029947064
3087247475
0423247878
0837547068
6616161526
4665024560
9121994215
3235535235
2861332684
9712434635
1094834614
1936934235
2045932165
4719431534
7379977973
5488848458
4204254204
4414144912
7202779213
1076474278
2453077952
4016879968
7372244254
6049544253
4772348463
2707972762
4187261207
4007941228
4789988452
9108790790
8020208201
4709999407
4082204882
2977447774
5314916316
3769050566
7718626856
8220956813
1228850816
5552554856
6617773316
6860810876
5075556075
5652626566
2872722777
8999906998
1311311803
1319195318
0353590235
9434612378
1086893837
6466201703
2879620813
2531496208
1628084012
4448643886
7771774717
7474647694
7773377736
1494874732
6540577017
8026347797
8033817636
3682177037
9948325150
9595391317
2071996113
6693031672
2075961278
2975377299
9520995228
9521335239
6698068069
2045004220
2828226471
9927358097
4087253815
4922556145
4587363917
9882339328
2980390292
2024222225
4522552222
4527252224
7990793970
0362330272
4337430497
6366960973
9373993775
5249233497
9920533475
4275700270
1120093972
6992633475
8353858335
8251313213
8290520098
7921412451
9991777199
9253306302
8221353471
8251446810
8973529133
8220456864
7005970745
7909359198
0709450470
8709524155
3975500857
7903939339
0705992099
3029529002
1001400010
8879599778

The puzzle

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

8177177618
1868886821
4315121513
7309931079
3472113742
3782033719
0466273149
2714076518
0148221512
3451026629
2929363612
0373316517
5223346482
0923313415
1679327702
0222332333
8913798836
1661616661
5599399335
4375334574
2823823008
1197521175
9344434893
8393981349
8911777198
4692231143
9699431358
2030277078
7083623378
7330381179
0007605674
8850306385
3334797431
5017056707
7747770477
7408276307
5930377735
0714607674
9354007804
1133050381
9566965103
6126695218
1708986984
1003660300
4522745998
4113933131
2526765255
1508655036
6562922225
9046000094
6100165014
3943303634
9334396334
8828224833
3313994331
9170694034
6470365034
1141406334
6890504034
8429305312
9508788415
0780420156
0520538093
3305526644
9229585193
9333793935
2709507007
0221520112
3285633556
0550405055
5636329875
4253668074
9001248037
1674849814
7774858036
3122158231
2635625633
4984749874
1105166015
8219082096
2626167241
7979779747
9733329373
3536313633
0717777015
8827819647
4213129247
7383527634
3571027237
6382177243
4957819411
8554921177
4452639490
3252889590
4454184431
3752112315
4254654662
4414944114
8507505898
5290802820
6477144717
0432130034
1178387881
6301060261
9176799961
6472386334
0172725034
5107089004
1171025077
6432082390
4752477687
4829350649
8743950416
7335662744
0056890964
7777770667
5592152915
7999667389
0711771714
9049990449
8401229522
1791331001
9701007539
0141096199
8791343693
0100333111
6459049416
8991119191
3746244342
9301203990
0274689417
4054626899
3403986050
9213917457
3223901787
0216336662
4002840022
0473909440
2423024202
3054644834

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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