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:

2808933327
5143133527
3855793543
7301347323
5833233524
7099977190
0402003248
7767220574
9929993923
3337731327
4461610468
9221115092
1932421942
6882464828
3444353486
2749415886
7344454472
8519853948
7694553088
4359964986
4884787244
0037887300
6655906985
0270330733
5355550732
6343030944
6845953932
3226400330
1901500240
3589180703
1910933404
5134313520
1942533582
5012123804
6334030404
2212713287
3034433804
4244440422
3111229511
4400053004
4709794974
0957995053
8919899181
2693396636
6639336666
6953366823
4707881877
2603768759
8797324682
2699289361
2176444493
2479124969
7264719184
2566525540
7547107245
2486114144
7748748477
1474177414
5569555955
2287444775
6408550549
2288013655
2498562165
3290037657
6490523029
1468518415
3280586583
2210002110
6698888866
9445494945
1131331913
8914978495
4141441191
2000002021
5139193145
1564838911
7894801025
8203322093
2777001915
1018392093
1637111377
4259355253
5516066116
9534738793
2176112226
5137168177
5517307558
2237720687
2957030938
9176780669
0819487398
7362289791
2556450391
1087559386
6038854396
3564557360
0679970996
6999909096
8899884398
0890089081
9629969692
3326773323
7497994494
9542727554
0392535600
9627569656
3692597923
9527447147
9422746869
0396982376
8039371587
8868379114
6084471387
8032034847
0784587376
4894598454
8780600880
0032424207
9768171767
6849346446
4337200703
9185070951
1239625635
9897144930
6775479035
6697717265
6665565653
7007070700
3344144931
3050309035
9069775047
4224741047
2942945747
7573826037
4518475637
3347312437
4040045047
1377071037
6646426046
5345445644

The puzzle

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

3663631666
6886682866
5551558151
2232202823
6477914789
3282214759
0741762781
1674904689
6772702626
1257882861
7155528539
8312172642
5795481392
8155335035
7955361989
4335353533
5519455115
5197571777
7955175973
8472428284
9043426081
2273505829
2225498785
2876041490
9276500277
2063996982
3515455155
9046004099
5275622227
6223523333
6578276268
2973889723
2766888666
4037660094
4190519990
2978521177
4590220264
2530646919
4577224770
6536446859
9125367570
6835986036
7885313088
3122313725
9922944233
6382998392
3133833323
5116313631
9925399923
0881919801
6487825747
6437541313
6637602674
4647906300
4667908961
6287979225
4163464444
7737877387
0467575057
6647266246
1940541151
2213904877
1344864502
2344836906
7374963076
2249194942
1323003080
2914949949
7870888800
5549195495
4188448448
7711611171
4537574554
2463144441
3604134669
7107568925
3117463470
2494146520
4587617610
4403537579
9836502034
4475171958
2735160173
0796350413
2781103346
4796111941
2485822585
0774377763
8830558888
2791317732
0544886022
4741836455
8399538362
0575172566
3882638570
5020532580
3060372036
8223888322
6626636462
7854778575
3768921208
6395904202
4996021003
3868807626
0758963911
0918999010
3765999593
8665996559
4558050544
6896866619
9628591172
2483503227
9116629103
2506522822
2428560201
9451595941
9518495159
3183838833
2163666313
9626777167
9650244616
3715122148
4255526948
3415173099
0845146228
3297932939
4845544585
0665606656
6750255250
9217111621
9121030476
6981438056
4910788443
2079895051
0215098170
1581535186
5958098550
2488082046
0599145491
9970790770

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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