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:

9818989814
4488288429
4469114365
5947947599
2889595528
0709897425
7378984598
3760242398
5803715518
8774489525
1082325465
3975395039
1148054129
9596022349
5880584744
0138513358
2940882838
1872122118
3085058300
5596339596
3379873398
4757117155
5385783887
1187511171
8696797927
5159749385
5477573182
8376753939
5675751512
4397870763
1036360035
3307997730
1118551815
2276636872
9959779591
8175039531
5944990875
5142986592
3955190812
5837867831
0535550623
6472224672
3531353413
2022228820
3095331550
0687630623
4382938613
1899758673
0358958622
7116051658
4617152587
4988152354
9986413400
2634174655
2687704153
9984191191
2437774234
4515145951
2926626929
8685465664
4141714017
7870887392
1191109171
5853880593
5350990395
1299219515
4199809597
9343690597
9132394313
5470592093
6073003036
4646026840
1100055109
7373473342
1112312463
8662215039
8416476000
8506215149
5902273376
9316922803
0108851684
8499563628
0316973286
4896155268
9996874629
5526555628
3967663779
8281261282
3766474624
4788764867
6884664887
1100780710
4252572645
7100110608
9453535459
4574835619
7612735459
2759813858
9100480609
5711875648
5388930328
0246779200
8019995300
1771141325
1083635335
0755570325
0330335250
7108801787
3374372308
9133999139
0953873575
0458882887
9899814646
0848655917
9954360455
9843338943
7591272595
0154154455
4448844887
5959855955
1677376777
9393393999
7526257776
0400000044
5519911659
9510941154
7600092577
0426034321
6373996339
1417972262
5501493697
1000140400
4374289694
1571230546
0607147216
9531155911
0397333779
1371413311
4004240264
0650111061

The puzzle

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

7090005035
7936580379
7239016745
7506972870
3907525986
9956756595
7597009777
1439934593
3206553636
7001570111
3621226262
4192332899
4562562556
1328131811
5287975977
4122501955
3581516401
2527395247
1598593472
3622270787
1488468884
5966996952
7844047089
1861119618
1847778417
8246479417
4175997682
9991616427
9247416919
1734668484
1225445412
8167517817
5570677777
0038008000
6810778388
6210786531
1137476845
1166515573
0870498868
5078671351
8008059808
1055565055
9179999971
2522528533
7722752277
9622099957
9910059958
3201555853
8743557577
8725159838
8735140676
1839545626
5244743286
0772225219
5725835049
0351535083
4422430224
5054442540
9149040719
7666627676
0788823655
5133810775
7753398652
2266322657
2788367641
2281991922
2783323787
0731610656
7068306377
5158885115
1760336640
4683188146
4199019400
8395668899
8222555822
8290345393
8769134033
6793585303
1295527678
1783153436
7811187711
4113631141
6465222666
6355757467
4285114512
4865700724
6413116566
6815158716
7115493369
6313144368
9117011770
5790991975
5149393935
8854664885
3598959588
5114968088
5190360302
3058981452
8818978943
3159963660
1373731743
4444545472
7717076014
9779303979
3876573365
2798233779
4132503949
4074803474
8078233242
1236976375
4276112674
6079949407
9059990579
5333675633
8899998964
4955610673
2627770574
1834695673
2672215604
8968073663
9837250698
0423813511
1532152091
0844952643
0588650061
4022110028
5353353693
1005056041
6661010616
2566252966
3733633457
9410214705
1304081028
7777988002
5550230478
8440718407
7999494705
0882880872
0886323058
1014131041

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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