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:

5209783820
3121084779
3975080054
2208099854
3978764138
7179777771
5812778115
2228022222
0921098919
3204880203
3752764253
2514166610
1949956320
0878586634
6571656233
0045150154
7833837683
3690086390
3677756736
4056264210
4280989908
7404000407
5214411555
3958959395
0493554105
0293920894
7294476947
0263901825
7254416506
4258566703
4654330943
2652069559
6657378961
1377348138
8684365708
4366333336
8682088080
6658066150
8924394434
1677474671
5313771356
3003305939
4404060420
2444242527
1118111313
0547411559
4203162939
0686641339
9381047516
1260671520
5967171961
4825588244
9567262957
2090622691
1779393971
4725569437
1999190032
2090362654
1865648022
7597602253
0288010948
3030407435
9001490104
6733676360
3939979325
6288070365
0838179365
9808479430
3161177365
6012790374
5479825720
5569524142
6046798901
0968960587
0060966939
2307575323
6476776476
0560770565
5966997959
8049800888
5383116108
1495392824
5495329622
5764382472
5895183575
1865718558
4786373764
9464144116
5890395845
5493144333
5425525552
2366436342
4348233444
4823844084
4977114717
5365505007
4326599067
5424497210
4425885142
2328440732
7741717477
7622426677
6412314312
5086284500
5146999461
5612984244
7741319052
2146411388
7181799860
7426723459
7889972898
0444474002
6242243826
2433348723
6441991149
2604691048
7406743899
7220545898
3602372009
5935074103
0359483626
1279533622
8314653022
0761633023
0466053392
6683333618
2223323622
1333113393
8058553085
6162635226
3513133531
6760606696
2137921312
3749119449
5575335757
2777388157
3511930996
3517638579
5560158944
6579123507

The puzzle

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

5799370749
0442891783
5226733749
3766695749
7802032736
7722777726
8333833789
4448842843
8893385539
6020990772
7541576600
7551936994
9990489222
1847913219
5849567228
5079577955
1977477991
7096976677
0851885558
9547477770
5657085464
6060087792
5664525492
7663209458
6065542885
4533553555
6150050156
7665267672
8062282652
5607507700
4208772074
2365965253
1211712117
1325815132
6538755515
1228941638
4231707762
1331822236
1308865884
9305712650
6668685466
5454727534
8588717885
0560950590
1113331849
1331410466
3778827890
2574955586
4790657835
4083820883
4771262129
1282982472
4645488794
1282108244
4688923192
4741977741
5675276652
8271271229
8982892829
1888118881
6785840746
4547621797
4864620647
4217419716
0127414747
6111919616
8844747848
4444744787
2837020743
4094904797
9215617504
7256435255
7636244680
0644700177
7244722891
7656757667
7545254575
2031441131
0984609908
9206702932
1837730278
1911108119
4446974926
7153795713
3381318310
0929074713
3885498716
8547478318
3195818309
4445134118
3162034439
3428830143
8969834043
5931134426
0991610102
4429994442
0035000303
3391309139
4111414433
1033331023
0317197307
0367118627
4323745040
4080780121
0227705619
2213717332
5187457117
0274006207
6360880300
4927192212
7436171647
6829296562
7962492997
6976447767
6846998666
7876900277
6966164080
6829222155
6849438880
6646953834
5496046225
5554761574
1705198595
3504068150
5705763663
2755352578
2524121124
1306226332
5492050400
7256775256
0597513231
0233414374
0503023105
0823949925
3807962941
1593531511
8853448454
3507077004
5223959353
0187687006

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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