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:

7165654289
2564158336
8186885899
8055300740
8065180226
7064974777
2155665555
5805888805
2066167212
8583558588
4549885484
1680808885
3120434141
2627222727
2362336222
4340307815
1347313680
5689842814
4322289312
1120807848
3883488488
0792077990
2611326312
0447074740
9352550555
9753386604
2017568130
9857364827
9653067506
0642455453
6883136661
6697767667
1807017081
4008909094
2523733507
4003949359
6207760257
6697928694
4888164467
6803921477
0206001642
0888884088
9229996029
8111167810
5052157251
6216297259
2040406040
8207067040
1194885289
6167054089
6355012481
5920313775
1184393261
5240243217
6008273377
9992999267
7671113711
4377743477
5555115365
1122772271
5894058809
0686866890
5229259824
7718414875
4474578458
1155819805
2826158829
4400896820
2089176800
6065916455
2185103021
6810800222
0489869052
2856302021
4181052201
5259559022
0070070800
3222222022
5440253204
6661002651
6080000846
5650530655
7414441473
4849871854
9449333449
8278271656
6698100444
3570801819
9139771859
0908130646
1155151091
3848292048
8444808451
1655515576
3332737322
3538432521
1246501541
1490231046
4718101558
2485215436
9295929695
2931396132
6699943916
0223289123
4944592549
0541699533
4203029142
1220624636
4761296615
9427489113
7973483619
2486116209
4987916203
1514016593
0114436029
5951115509
1919117559
3213330223
2146126614
8006086094
2734011515
2295243233
8667033432
1709043632
3500494865
3812333682
5395393495
3668414863
2722847282
3513221535
4162439161
4923583653
2859506290
2909533522
4962569270
0109991099
0453151033
2722272222
4802544050
4969290969

The puzzle

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

4004014404
9939367193
3769663936
0083080381
5599955990
7880654403
7000360196
9054460106
9047467153
6886210186
5369999355
0640600606
3941899649
3194242292
1105110051
3649904553
9164107279
3345823121
1960983122
1369872428
5570610476
4920505894
0377591311
5566242680
9467584821
9525559595
0450540545
5676566685
4363636434
2407227704
8177157187
9172979190
2806668092
2641634612
9733394673
2457254612
0385062017
6638198692
9635667172
6435569110
8934393333
7039603609
2547848222
7797379797
2754573727
2757346159
7774568060
2934836998
7757326130
2034375292
8193599831
6763966997
2838133281
7553575577
8247174249
6767125832
2243990072
7233801764
6193500348
8757135004
0687969978
0146868978
4095768959
1881668974
2923459358
4349936984
1855058071
7773668377
0881849808
6059665950
9721000926
9722065068
1861784275
9762594590
6722742969
6742774627
8768060787
1821081111
9262462922
9861661194
8567654279
4077920063
9967623219
2076697333
0079385702
8017377783
4509649449
8076997807
2965363399
0926508266
9517797351
6606016103
0000000200
8118841885
3252552266
3515212206
6230190385
1914297215
6084747855
4533516361
8858638865
0737907339
8153558172
0791097190
9999939699
2135037169
2057139675
8529139872
5100188892
8325738130
2492256629
2085563450
5950056740
7779366428
1046852329
3963376339
7233332798
3414443441
6766668476
0576056620
0094941486
8618153997
0242415497
9230832487
1494439487
5999959996
8446035480
3887713877
4148441481
3434445430
2299494282
6611610466
7007047507
4446646648
0574551490
3193217547
0521640292
5741749468
2368694697
2466847607

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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