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:

5939741033
6930742786
9715877690
5914567759
5213968190
6744996446
1819559819
3270873877
1435757730
5923823923
0677072673
7242864643
5034210475
6656166983
1824272465
3414114643
5858876685
3994664903
7667716477
7261672465
2570353325
5307939700
4991449644
1478041187
4702774207
1492383957
2491907029
8397026810
5477352014
4972480868
3626434226
7788989878
4000110104
2577372272
2234999029
2624944569
4504322630
2089153528
7076988677
2587485081
6035078270
0805942268
8835318561
5692021378
0832349758
5515355355
9095999909
0835005053
8002773782
6812926611
2662989692
7221244215
5355435540
4549938954
7517515117
6180219615
3148145235
0329839994
4938134590
9251339614
1363654641
6473933580
6044443590
2563697181
4775948161
8763338772
6560446465
4274343273
1345959344
2024622664
6591270810
6793823161
5775259614
5596127714
2435909453
5595999599
6475176614
2633863683
8780480087
4556228452
4244994024
4744646472
1053535018
1221167122
9510111069
6558631014
0012662412
0769411472
5902597124
3008234172
5536262365
0509005790
3555755337
2922222268
1222132319
2762852390
7831865367
2263602255
2105835768
0893352318
2207072204
7155334577
1112124111
4540646150
8555958962
0348438510
0193784164
0961174910
9215148100
3955448171
4601761740
8572778885
7738338878
2787828327
1066914906
3602018920
8953824878
5957778802
7477468946
7586634706
5729079705
8959333993
1144316144
5256999295
0402770007
5709304524
1792063461
5729043362
1254310312
5256943783
5169950918
3900463014
3209135501
3950618290
1209104960
5960151161
5175055177
3209440464
8109669808
1167916191

The puzzle

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

7610370701
6913016303
3837033803
7527007727
5131953611
6111982278
5534032053
6817916034
7517931393
7637091765
7399179713
1712821278
2685118268
6870800206
9378553757
9390166666
2373803262
7389812474
9319164734
7718158075
0681781700
2563638655
1500900090
9146747441
2863333363
0860982006
2146743162
2546754803
9660722459
9562759409
7070038700
4241124310
5525146512
2884008829
1813313863
7955234822
3048804863
3425578810
6225508800
0119606712
3376443649
5032666306
5859589585
1459696464
0171371711
3339340486
1379489048
3279689768
0371584142
3371607310
4958518000
3576606697
6426716897
7292536812
2516213152
3239933292
0100019007
7555106152
8318836818
3683998693
6390767093
3316443413
0264926696
6309590333
2014556251
2000587080
6254425323
6099567645
3304505352
6066401971
3376819124
4499400273
6480497771
0670838442
3533149065
3495113443
9677477779
4333439434
6996666996
0580800080
7669984960
8007271462
2725821801
3239823208
8454277708
4447774408
0000021001
0010663900
6828282862
0777007700
9551590046
5843794154
9033337293
0860590253
2022693673
7772197176
8303338053
2224223224
2902290298
6966224639
0440444704
1192191129
3788837386
9951911299
6796996476
9525611296
0066596479
9009791756
8648311789
6494731489
1671343165
4755647165
5857370583
1199998661
9019199101
5203477181
5117093163
7388678465
0563597101
4496940161
5940304934
7416551777
1633236233
5808445488
0301313530
5813528957
4408377095
0448592561
7313350304
0803286810
9412451517
4486794842
8035294886
5849334750
6701654712
5448534854
2499294292
7485554780
6116651566
2381888317

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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