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:

5381648974
5538781287
6880090422
9821060850
0538788377
5540110155
3938633392
6381116113
0333773373
7826022820
7438948709
6633136561
6962646295
5521515472
4777774877
4831476499
3049946849
5914278595
9717218772
7663145569
5236422232
0844048848
7379793793
4412664112
7162333156
0162363173
5174649942
0144730283
6142765380
4134728528
6907053627
5769251697
5857456757
3142603727
5415453127
1111553181
7114441677
7348283127
8768858697
0575700757
9139585777
8248571676
1655553379
7128553432
7668583266
1425552124
9169559999
7398093978
5258282882
8636380636
1198884819
5944774549
7681171186
5455656045
0393173159
9961074149
7600051156
8834373059
3761521089
2226681855
9617428264
8709728994
8678728258
8002816964
1666818754
9991518594
1994701794
5959908958
0121620261
9629698968
7032171180
7184509327
6057192355
7416077725
5624677025
1377391327
7573777753
3133332325
0770507052
4418859184
8061119810
3468664334
1727117171
6591065161
3511931913
3091180422
1091790834
3598070843
3418147696
3718143985
6004090446
9041994318
1770770715
5505555020
7737377723
7241455325
2465970720
9716994310
3242130318
4683554718
3853433838
0553853655
8347337748
3934544334
5425955959
3945348720
3537492867
3354425933
5133580182
3354518001
4595576163
2556103376
0592997518
4643524147
0685741454
6084555582
4945114991
0516717151
0699969909
2652466222
9551052221
5881954221
4343484081
2802602181
3051057271
4629954129
0261100261
1747882471
1158257281
1588505781
4179997377
5354775745
9857755797
4004744444
6094994496
6857907300
9107918412
4174795333
4854924724
1107983987

The puzzle

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

0936797757
1405155511
2168666616
9198799879
3040330333
2435106352
0135561007
9030648520
0145785453
9968326197
9660721474
8663352497
6233118665
2130629964
3533181495
9260396963
0593115115
6563756576
3175111511
2630664323
2358559991
1107349314
7607226175
5107282627
1004325576
1608551165
7867267777
2152055115
5064164501
2267369633
2225590215
8857875873
5256969529
6257764576
1090151930
6606659239
4362891579
8526810575
4335069815
3250259939
1241293756
4261910776
2986276553
3159223765
0723696866
0880990842
1083003153
6666065706
6165511566
6222526575
4942444440
6564746666
9570907757
4636833666
3811999119
9516762472
4636999534
3814910103
9531918970
6818969344
1008110181
4484848478
2422525425
8189787797
7637737776
4682721438
1488185683
8128557697
7689766984
3689708153
3569446099
1563880242
5472421665
9462414668
9639702865
9439794337
9662596692
5573830355
3468488844
3262426222
2811121810
5088339508
9819861998
5463506395
6999119246
6074616305
4621031848
9378209790
1964909506
5584136998
0370003497
6464646420
6062256022
2326765272
3733739947
8342656292
8895563922
0192863012
3038363477
1885545492
8440258454
1581062854
4830184814
7506977652
6650672671
0118178610
5550252452
9223661392
7858885271
5847437854
7657863006
4414742105
1851745836
8850940835
7602013135
6115335136
2066366035
6111116111
8838842838
0346643603
2537422554
6424777224
4788348818
1001301103
7792992292
1721302770
6724315864
2221421402
7028301819
6798347499
6055905556
6142626266
1909919018
6976696679
6387333773
6305301356
6372886404
6085654594
6382927117
6945681165

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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