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:

7569999969
2415725145
4744774447
7574354045
2692772692
4569701760
4574719543
7676775037
2672948553
2694790431
3401154155
5654755161
6680854557
8944902140
1484454137
1670111167
1915517945
0515054130
0510002551
1519751957
1149908745
1639907861
1101992460
1037995500
1677902544
3171531751
1654315434
1039909991
6307974906
1839989131
4840080841
1166818654
8192999281
5161544651
4985359423
2086814621
0913799884
4199498844
4338559853
4759284487
5009705575
0343443744
7745277775
3560838353
6898198818
5348165555
0848823417
7300498731
5743615131
6340255119
1058905853
3511416551
4836925870
3814315370
9280815050
7115115071
3373306373
0650055600
3263424362
6717817852
4614146412
5565625464
2777070025
5156511156
5052590658
7519216155
9310820152
3349821416
0050845556
5744596452
8074848884
9549885879
4445645655
8670860006
1277313227
8574306284
3470862905
8549377173
1274632780
8270860693
3267333732
8666336386
5512551551
3079679603
2232130212
2666145667
3267370618
3237930941
3212328924
2662580122
6425757526
9422090024
7465222372
5626726622
5299775997
5625767676
0465777221
6425096949
6625084627
7425720008
4033646603
1641441931
9919621689
8458500845
6696116914
5598211983
4145451615
0956826913
0098926683
4131616943
2660740176
8243267680
8663529672
4087234990
2067745102
4282774287
2060622060
6067887056
8643743844
7188272821
1636363183
5416799431
1624279372
1413215970
5416588743
1436334443
5225152281
5313251335
4314881433
1634546344
1161950904
0431651934
2947250221
1620911708
1734451464
5333550733
9999990394
2921292921
8877171468
9302212904

The puzzle

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

9117719719
1794949494
3287998839
8885333838
2730730274
2787909457
8234488800
8287981648
2187791380
9280767861
8774135964
4706622633
9706151793
4806396123
8106127940
8106110100
4764646467
9706363000
2476444494
8351051151
5859185494
5716933739
5959192366
9883939251
9952108390
9815118111
5313533355
5787875788
4899984497
4952995429
8878373883
6906086900
7212282175
0533332503
7066971296
8438632575
4576332190
3659972893
6555372891
8620073183
4964642946
5333994335
5822662285
0881118408
8554559158
5472292248
6627842488
2595812488
7368612855
5452559348
4056361109
1694618305
4954857189
6968962986
0718818905
5909737905
6116111716
6162062106
5644848624
9962262389
8407644457
4512857492
0833454495
9327456216
4437054218
5056959467
2166666212
4556454456
8596664895
4808840288
1795853788
2309959678
6808055723
9044829690
9088031610
5969959690
1712621726
7157173813
8778449778
8446838684
6080257926
0380406687
0073453638
0870405119
0088344641
6875998675
4688488464
8089288098
0411303111
0370108037
2287403189
6740802368
9194716081
0111923895
9188612785
0990994089
0000000801
9172972399
1881113168
7885222785
5940134040
5448322188
5428990351
2446773028
6448906443
2263332622
2446444443
0424340244
5428784527
6940999609
6331793177
0582653886
8429756434
2159511476
7765814496
6636916639
7817121778
5137551577
3993223494
4864994186
0091727245
4661002418
9834243332
4068153032
7431326481
0064330440
7866286126
0491441044
4338033384
9681718618
3681481366
2979192119
3797170913
3562111111
6468338646
2692124991
2668120277
6999264282
6592415029
3569188078

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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