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:

6703966879
9907399330
7254957274
5700277750
3375377357
3973324780
3704307855
7744932038
9307991633
7777300624
3408949588
2778474882
1379931319
3847487384
5010151001
3417923317
2048426196
2870939465
5779486792
0410444454
3337635764
2622132611
9083863180
0335301533
1153515933
6222215784
9355911134
2558103560
8596613383
5868035583
6223091861
5747560774
6455300813
0891240671
3847411631
8938998834
7722147512
5006440866
1616611671
7007300753
7990712311
7124706052
2764773313
7102868977
7564563671
7860777606
0992602000
7902121161
2597522575
2124821288
6181368116
8160904118
4453354435
3342832284
1980515050
8180327205
3061873509
1980972575
6160926427
8382315157
3553783573
0066003463
1902119128
4479449947
9696913699
0923613549
2501383576
9469403143
9859613143
6464589598
0230185685
1627110723
1010107592
8860915755
8930981989
7011371713
0267961077
8030101103
1920111012
9835454493
0328228109
1860418690
4636464679
4861468170
6821612162
1110718670
7773118177
6767767107
4204244402
6639222369
8180218120
0950777700
9978797797
8399198091
0250775552
0999703008
9180728245
8978111089
0950294263
8309710289
3457273420
7088282770
0778678877
2685442268
7108178111
2688100107
7088548031
2788282975
7008496874
2788212816
5229887811
6679937576
6818936185
9668330278
9869121744
0251155511
6828886888
9763599695
5679559956
4619996189
3439923311
2179528533
9432665435
2391526839
3391565210
3539553359
9373597739
2441824014
7192662192
2735626722
8957584346
9808359516
8366369343
2628784903
7923059740
5111551719
3338384330
0891089019
6964769743
3096064906

The puzzle

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

7440544447
2662422466
9592555125
6549999969
5477117747
5547127046
5542948122
6477591853
2471105071
2449409845
6323436662
0078102078
7878977777
6974966649
1516916695
6918104486
6878164651
7574938073
6828272622
1816454050
5522276902
8819269326
9766269428
6960369865
3612479903
7466776746
7067676702
6993389363
6596869468
2222221925
2550055200
2244495482
3335853238
6703727043
9998993897
8731493447
9886253843
5678257860
5958997030
2833755437
0872401851
1803787574
1302454484
9602228987
7677786870
7813733177
1702017082
0379444909
1672421712
1897271221
1047140176
1367556313
2202672620
4449609946
1378713987
5656479326
3914756118
5329940947
1332749116
9769543123
3877088838
1825884421
6717581088
9762582639
3897078830
8300778030
4498884909
3001771031
8888881828
2023622680
3900440777
0085649828
1930090845
1045290998
9185456828
2791791790
7271210927
6466846148
5885590875
5202250022
4074734948
5871160821
4378111542
5897734535
5898348718
7091797077
1383333301
4824884828
2678776282
5888188888
1187521824
4421126141
2569678612
2127603686
1109784342
1588111185
9129217992
2267062627
4421644444
1301711377
8888989805
9092911920
7777949777
2011034901
3937731973
1005234720
0928869800
7420839973
6679789923
4006084975
7697355618
5567772030
1864388770
8594447208
3697307097
2597338795
7394473399
8768776688
5677176676
3866338663
5580059065
3544445349
0140149100
2622322632
1818515598
6014812145
5155125092
2105840562
8551519398
2577542140
5040504500
4428343464
0151551111
4884848844
1435911495
5120960175
4421893533
4154803083
5054890891
5535383347

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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