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:

0417365519
5618230760
0927239341
9372976948
6978185452
6372372336
2416111144
0657200563
0227970022
9978079797
2446372329
0117455848
4584685336
7522788830
5265275376
2257572652
3733353376
5226425346
8817887828
8232888230
0312348954
2680531968
2336533249
5072371055
8332126986
5212512517
8370770038
8038181383
0482300304
2176171617
2037691157
9996494266
9943745833
5946005739
9943984722
2946999992
9947790999
9033609966
5893285525
9153451591
7412472449
4444464544
0022990022
3380333308
6768978690
1415438520
2336164429
0104178448
2263973644
1818437349
3915891519
4484649844
0017500705
2942492242
3878939888
2912983943
0987590411
3448818048
2417872963
3419503754
9686767669
9887988987
6715919571
9741444974
1906397696
9885320193
1886490516
9912990286
6686961429
9907316575
6439934969
2991222298
1314141431
3693469693
6999779999
6939149983
2711439840
2399763180
2934762513
2691126441
0932397310
1499552221
2409515625
2433078042
2411341878
8812518828
2499399936
3903505353
2431231134
1221022211
5968896868
8286776832
7030703037
4103331333
8263738778
4238380868
8036726473
7266777539
3968811429
4280713545
8307373303
0161666606
7292323727
7712477114
5602356282
0392345307
0302467712
7198339913
8112373116
8612331501
2471511415
0414604001
6147074764
1116311211
2129552512
0176527147
0149676688
0446529302
3441582718
1427573472
8911391534
6937298994
8103319165
1707311954
8880361206
1180318811
8781818888
2903222223
6902330050
8837388338
8690504991
2590733362
2190754308
7699733057
5195582286
2643776776
7190670176
2199591751
5565454456
7690800977

The puzzle

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

7003153170
7656565667
1204084201
1130313313
3893398063
2249454663
4759283363
3235185613
5300975371
0143964110
6372679445
5249652465
4035001113
0123481163
1739671316
5832552385
3934639446
7919371369
5444554115
2243202163
8644636948
2233335128
2597112905
3393595393
6003330621
0559216628
5747735328
5598536908
8843216928
8359911945
9709436373
4705031399
2781159519
2710753121
7708436193
1114939311
3530336503
6165156170
1191937129
5595533597
2083205283
7918591857
9055595505
3817073870
8088535580
3372271550
5633701585
3469031507
2946501500
7586981200
4484340713
2655943372
7271642978
2277416182
7328416942
3334333343
8382802348
9779117987
4777040772
9766446192
6729192927
3932532342
4694444966
4921649441
7884554484
3734549429
4681535963
4429443952
3782691698
7831410255
3042670850
3048924105
4258644109
1978117525
5279964866
3479999979
4953995499
1279179113
5028665252
1048111181
2986228634
4297778464
8004756037
3922874060
2957074498
1747374037
4824226804
8080808498
9474477094
6655555666
3371211343
3360811229
2501203447
8360310561
1566520626
8364138161
1301515353
2528225222
3660339366
3236836336
7929992999
7164367473
1963396919
7894497779
9185399354
7964909208
4984382260
7163347498
7923305488
9184487441
9119569581
9290707952
5165773615
2823226833
8447773474
6541076471
2110879635
4368073574
8377404873
6341223615
7129412974
9009000919
7872802785
9918975988
3677737466
1755630469
1696700989
3311202484
0909432184
2014305974
3353535358
0009220940
1214944199
2920290226
4341331114
9016230350
0949734158
0428520756
2087591124
5967244949

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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