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:

2931828333
3331411343
9981551599
0690390390
6069399760
0631326288
6341804062
3999837145
3380527451
0630466851
7082884207
1054415041
3666630660
3477347573
3063333663
0851017643
1440627570
0393885077
7394913640
3266444261
5048513758
8148552187
1048264944
5168161864
5168589910
1048511111
3143224342
4160541681
5048544550
5528182821
9798985571
6134886471
0734695861
6621292970
6734985274
2738933832
9667861966
9731237929
6691696166
7124994942
0057707201
3208211744
3209585707
0540327396
9207545288
3247332443
9537057537
0309703030
6700270060
0258505804
7052364449
1352336094
7592394470
1079353165
7302368557
6391118191
1052331521
9312323392
1076766606
7507373773
5644656455
0177173614
0681880116
1982912893
1981191558
0783291156
7443770198
1324781516
1061556193
0447916478
6831486019
5553612714
6738279015
9709464210
1540217014
2725597265
0044004609
6070616010
7977789716
4274272014
4193720011
1492703244
4114595734
8892540524
1899728086
4112991111
1898588311
1894198948
8402708227
4899789947
9869854122
6218452468
9321135574
9804155020
7304633170
0323133120
7845564574
1000165010
1255451424
5652252162
9794913438
4603039398
9495839098
1517327021
4063239097
5825115058
8393931398
3543113451
0002929021
3329229337
4048216012
4219316055
4165606005
7348207010
8454416962
6195116915
1662665612
2077027058
8414114469
0600006004
6033061083
0329293210
0190521015
6755118567
9853558963
4575251280
9831621767
1353913267
7128198017
7583993565
7986968974
1737979703
7788878689
2222333227
5777759773
7906058683
1115878287
9380118279
3701778983
4243368777

The puzzle

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

3251191914
0648999997
5693698998
1190601214
1192895738
7777199741
9789775897
3185891938
4493191934
0388808318
8288694986
5340473504
1218218222
1724147216
1755155721
6111675716
3153517286
9782558916
3750613226
2229183526
3823837139
7966360067
8637337107
5012737059
7667437469
7003737061
0201992100
7407797057
4993334639
0444920449
4359380704
7959935597
4750998282
3952841609
4752982498
1860916011
5352358533
4959339343
3795835575
4432828483
0129660602
3973997373
0142440121
8248323245
1019790190
0229960458
8149711433
8149314907
8179693052
0239901978
8903299573
7641315244
6548989960
6648495448
8504383572
3004333343
6693666393
8518288838
7949049970
6541999645
1102111111
8516181515
8252055702
9947194794
3998939993
1117144726
8116928799
3212952248
6552185517
1156973499
0071801380
6631646113
4428462484
4434778436
1396138961
8285671436
4101405480
9269438381
9597208310
7056662310
6348935288
3377156736
3605473235
3347096811
3325981855
3325111523
3577070037
7678777677
7343733733
6005900035
9589505198
8338836889
3284832844
1237667162
4977774970
3819077849
1814809189
0162206170
5447006199
1074604168
4269041258
9289074720
4725407240
2269033178
4758308420
9765393953
4258445448
9279007729
2759479427
8483244231
4044449204
3348483314
3939997932
0602206462
1454738547
3513296532
9510809214
2768596264
5187747217
8158706300
9238038982
3177973719
2134233211
8535683165
7515997171
8135924389
2111291061
8135222343
3234647262
7234939664
1411814810
1118108811
6616998916
2881286287
9996336899
2807638917
4029386811
9292008819
5227288910
1374917816

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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