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:

0270207208
1505155018
8363322863
2637575634
5866550668
9454852238
5021905034
8554022863
7807852633
0436755318
0989599599
4374747443
7059307355
8751351873
0692792971
4379362279
7699318452
0089749851
0792099914
8359386279
1500101510
0777370773
6946962989
3664664763
5050158031
6825652060
4312262071
3307500969
7185761914
2242100083
9396909620
1718671896
6768872866
0703773070
9911339144
5835631846
2433779876
4589971064
9551231920
3349902864
1174369715
1402952797
6529492711
0639462782
3275874411
5929559212
6227792777
0007077091
4478462487
7171474511
2914731435
5914171672
5970709796
4570125831
2570725699
2609792977
2574554592
8920111988
5866766655
6617116116
6956776696
7520777200
2584152214
6226366626
3130735333
6120165109
3950770734
3220399700
2580117003
7231730050
8094489723
3413262783
1060062626
5969992088
7953872028
9557599725
1180181733
0626862028
9006706679
8161871688
3632788679
4570142023
0672743941
0833511202
4580545924
0887777887
5862265212
3574575334
3237979397
4620111426
8844855182
4446746012
3858942262
3534333235
0857520949
0548770040
8817588787
0884904189
3858088058
4436863486
6050586560
0040552310
6200744241
8028474634
8000785179
6278178287
8454485884
6456466644
0020700070
7001511780
8434532773
5454630982
5955618484
5634331937
5455327437
1469314164
8667286682
1504941809
5834658483
2955655259
6558565555
6153881861
7616966966
4847333474
5284555655
4116381215
4158979798
4240566307
6213909859
6614839878
0919198717
4222424224
6776756367
6926069280
0888998083
6475899323
2071798227
9305368297
8458564267
1472694764

The puzzle

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

1541711751
4208148688
1318418411
0903909990
7305135313
0208721960
0248130087
1905411772
1303257090
1548146223
2573999231
7370565078
6710204826
3313929569
2350960551
3316113161
3750455524
7563995356
6122616666
2773575377
3475508333
7614481627
0682659267
0622722364
0614124116
7682772767
3675172657
7664564667
0924840022
3419431994
7170020771
4444494345
9379993739
3434393194
8142993824
9957893894
1497993771
4935294334
3557223164
2323724734
1237841398
7066748752
7086357394
1984753094
8565413392
2298758792
1281141722
5733517354
6868846358
5309153190
3135378923
0078974405
8735096756
3033962567
5703960321
6065959890
8933333833
3108232380
0768086880
5735737735
5015150051
5437654355
1834540533
2298008282
9896111681
5436543683
2886695267
2036110878
1837694482
1418627395
4274426122
5626875694
1027296970
5328866489
1509507582
7208552508
5007117575
4526868683
1374414434
8629496629
3599931526
3633881606
2145183273
2499887095
9439561320
2529596592
9496099049
6135961361
5243852282
3649769499
9169886911
9852989289
0225924590
5050356013
1911111494
2210416913
4512218291
3688056481
3350654019
9001921990
3898378323
0181585326
1092178768
1541676728
9397876726
3333376333
7060770764
3222772426
6127686721
0007708758
2151112111
9179179199
5876262565
0118901019
7877977178
7116186078
9857256447
8818205822
9118219942
7857206779
0224873597
3098908516
9147801596
7239111397
0048017556
1111111158
7777700377
9090577590
2111111297
1403603516
1111161315
7438448722
4240404462
3874228374
7696796437
5760498467
0978228332
5994764367
4728128374
6048226476

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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