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:

8685665684
9899996988
4889885598
1177337818
7776716763
1088417888
6134195613
0197981568
4912986588
2224137718
7248924879
7762666766
3007603003
6285065326
7683538373
6683989207
3065083826
6762113415
7267533835
7265003605
8868961107
2384418194
2481985162
8027315192
1943878174
4764773164
0993998002
4949417894
0651765107
6777687672
7949779946
9033030928
5228222825
9290949129
9772912749
8172030829
7755550848
6005539145
0640332929
9173722745
9679076379
8855855885
8161816668
8845343848
5021995995
8151961661
5851876385
8851906032
6841355170
5621826538
7221027100
0409190461
7780078908
3327373311
5559795671
9510078911
9319528111
3029090100
9331121301
6101777101
4258071155
8374678239
0677850917
2487818556
5753611516
6175175136
5511818765
6112178512
9777070989
2556251256
7770207726
6366663661
4497849802
4488178431
5818551824
8816277736
2740669004
5818077632
4620773636
0705753801
7072118184
8490171491
7597605017
1033674079
7270186037
6579156217
6295155195
7542175557
1430505144
8013618803
4836999494
5755957977
8795785785
3263863326
2742772784
3736769877
4292996648
8435743826
8743942149
8795932796
1875387715
3156347933
7708417119
2111616439
5766018483
1993111949
9899448489
3883388833
1755717715
7513157132
7447070474
5555625650
3950395302
7300337310
9982195120
6056835104
0834625350
2918935450
6770095180
6946027320
1691696111
9878198878
4310111701
0977887077
4211551124
9271143433
4471616356
9370588045
4870689898
1390627522
5775449726
9705642551
1575223012
5772285589
4715985977
1855914191
9702627602
4302233342
5715675165
4574252455

The puzzle

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

1288888182
9788449898
4430044046
8945999999
3048330480
4088942698
1748084582
3089088480
1045302511
8040965701
1811818910
5111591251
4734434734
8283888220
7377137177
4682491217
5532431238
3329198251
0026194917
9219718734
3357364222
6829767229
9228567401
5038294227
3908697202
2448554208
9044954049
4719184791
7702667207
4252597522
8917287861
9189111199
8199781999
6415346644
6614516156
6189364353
8619700727
6689253769
6187343727
8109759750
8434200823
9914153923
4916501461
5599534985
5516789276
4522755424
5856118185
9934222229
8415444454
5849598875
9664103682
1491647465
2464427799
9604426679
1916167535
9621112661
1617666611
1464414346
4307473047
2986862882
1453033150
1349033013
3807738333
9933639933
9126111631
3339768771
9400007356
9349735662
1943088501
1936758057
7003930079
8555987599
5746747577
2622286002
7220773602
7610236079
6211087599
9890187622
1106583577
6033187502
7210051588
3089425541
4027623539
4237723681
3880251589
0788559748
1118841481
4646646586
9636963639
5115823581
4513361554
9373889597
0074390571
4339126357
4089304768
4033133301
4814888444
1380401348
9081691696
0279394377
8554952940
2538229807
2864799555
2538378180
2544308365
2554755558
2559353535
2566256622
5538235828
8843080888
2242234282
9979999770
6006101986
4503007403
4555554453
5568257786
4184894483
9830541782
6530734973
2111631280
0398757626
6524316705
0311534403
7563561862
7368101828
7593337337
0505100021
4354555454
1511511151
6368768686
6693602260
6653203855
5665540143
6192359470
6190383833
5652959959
6360550063
6143343663
8680280808
6596669606

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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