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:

1658665616
5581334518
2602606260
0769479074
3972977979
5958963805
5678439831
5611350445
5679330443
1602310080
9549949765
0464034690
3233803728
3500990995
3699373269
2857894999
4382549895
5691943625
6401430799
1220193925
8204008420
0244702222
0271100010
6988448746
2166336312
0161109125
0101418699
0284255880
2986405447
0261467432
7044545544
4026326606
0845308450
7939111973
7531973765
7939525044
7034305991
7036533343
7049518222
6044588550
1801810128
8963969349
9044191014
5977898756
4340330443
6109211729
0927630148
0574269759
1069901454
7627618344
5327142947
7522162379
9356063151
9525945389
5722320788
6356332666
5527997972
7325121555
9663133616
9722666662
8191794073
6021040120
8197951288
1677723525
1090905565
1021111111
8110588150
6197966179
6077777068
8627969889
4110004114
9690490946
1179971962
8008768807
5268756785
5584850942
7918294104
4066058905
6083704196
3683308144
0104541441
1992559991
2533025030
9207390969
4063996069
9104321614
1103984115
2962097170
0903002660
4974319207
9683796979
1223122172
4556665564
8898488888
1904310191
4623787810
4583122701
1986533423
8293746618
1623420464
3134114243
4988833488
1019019509
0380983039
7933999873
6639439233
2183423888
4184733579
0611914503
8785689288
8451985449
5126662556
5612512515
7366996879
8779177787
5312126524
8471698971
8646538706
5752574468
5371981591
3882585885
0861310188
3476749366
3329033332
6143536456
3342343711
3167553590
6446343933
3169576238
3829753749
9997362234
6598905020
0997138949
6857939709
1455388377
6995959696
4267373722
8456118854
9888666889
1590700096

The puzzle

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

9812436568
1588640074
4585401455
1319078758
5588163533
9840790707
1462114612
4398448393
4585053545
5119911595
2427334423
2720272200
4045845444
2598198922
7167917377
2798144367
2147491289
2720856044
2525122813
2590317085
7546664173
4443994413
4445454444
5757515756
6716118476
2395254176
8738695444
3848868446
2907194676
1573594446
3588238258
0455050540
6631631663
9212091420
6305350503
9995230428
5181331300
1408851400
5613630563
2162531260
1601216660
4953397933
7975337379
9334233933
2578555552
9531365152
2675291479
9305302098
8303268844
1974362291
2107272121
3246116431
5773656577
1617331113
9156956562
2747348197
3607253988
3606517534
5603386800
9653650919
6584556689
9292222419
3734733747
6661613663
7752778520
4501052620
2205276797
1153478463
6994058683
7084173587
3322363362
4890990415
2996996922
4343334403
3141318437
2702290362
4070594495
7065414463
4078716402
1130036332
9203865350
2541465390
9336045322
1510745347
1655459340
7517559197
4003545350
8555865458
0620260742
3378448389
6889140190
1711266196
5572257127
9185941181
9019833181
7577757021
6616661296
3449943193
6717067140
9038330187
2743732273
5011717511
3421113233
2036661223
1917917997
3716169950
5041130151
2996680817
2936922046
2441728289
4656945639
4584885648
7464636714
9957598543
8020758027
6248858529
1057545649
5893136047
2908925638
3814595639
1865352158
5592301990
1555542872
5315213432
7713304986
1505515555
1093319933
5865258526
5755355753
7318131780
7318328598
3818794457
3328981402
2416312352
2418700154
7326173136
5168955669
3015330013
2438634866
8918776187

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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