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:

8525204878
0250093967
8443494808
6045601958
2458271378
0917971908
8875228878
7858507458
7553393357
2222004121
5271984251
8028075104
3119621889
8045446485
3179983367
3188992139
8120081128
4279449729
8011611601
7145214424
0218568016
2535868315
3089419031
6196618768
5693615066
1391318321
5355515531
6969668968
2145524015
1217228716
6488912313
5689565024
9699142808
9394101299
8474522668
6178575166
8468488848
4981918498
9394119949
9699894696
8844483614
9999787994
3288638627
1150031065
2665551486
6448253084
1852883921
3897581684
2478588466
7341188694
3536115357
7180500810
5305955553
2958485885
1201777717
7901141100
7201490662
8280589573
1908417580
3206541122
8246828228
6742645662
9272692977
6412414114
1012111002
6742142695
1212431955
1246600039
6816610140
1442817662
1600149287
7258847187
2839347656
7071537155
7980837267
0367730276
5561516655
8313330287
5444747157
7132632167
0092182509
9177562517
2087906609
8091106593
0604096602
5552996502
7994942697
5355363253
0161106106
2615442519
6055356660
6997333995
3576337533
4118343448
3803733388
4906368053
4555379875
3456347542
3877328604
6016315399
3111911131
8233222288
8638888888
2515455465
5695395555
8233363610
8631835816
2135308170
5639216816
2695830459
3981215978
2027813381
7035914901
9763463976
9173015376
2053353225
7796395376
1111111981
3833383309
8882424288
1333192699
0350895444
0732891844
8172325602
4291895422
6169191604
3223929322
1144113441
9558995895
8429442684
5476255754
6874666427
3602933020
5797779779
6303533635
5376505288
5676310593
6473720592
6892506162
5677722042

The puzzle

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

8621745833
0321120257
0925702457
0961638077
2626760790
2364333666
8621716611
0516251601
5971171217
2205150501
2009997420
6896666583
9390990399
6637464337
2020332098
6640492493
7381490587
9150564598
7190094498
7826660385
9551126847
9026536811
3676031699
7056160732
9229583440
9221191114
7621572665
9539093339
3056550555
9316223239
9999598335
1066166168
5993395329
0820062078
3613916913
5985496333
9793162975
0850366338
4727265919
4542636368
1956395133
4806556660
8856222620
8709474877
3156935599
8106983503
3859416172
8856292564
8856453056
0859475208
9834343803
7672624607
3985913985
6066602465
5996995016
5031813807
4415004009
4350304406
5473915685
8661923016
6211874399
2168847707
5599175594
6890777387
1183474679
4474117604
2391111379
5954544359
7297928797
5888474588
0144505455
2841182224
9691296292
8941316148
9644799499
9641368035
8641717545
0141794790
9144172678
9941980670
5353346521
4880407916
9626547426
7755208526
0899617576
7766776626
4448848478
7774517456
5187887525
0990206912
9191106719
6968668996
9923392318
8666661236
3555115935
3703812336
6478915216
2773492795
2724296936
1526828316
0539876217
3296831348
6619706095
2086583045
7886493290
9919996319
1166816048
4212131220
3332903295
8724282447
7194068653
2170896655
8877638253
6937628793
8805893512
5905339550
6666296612
7666663793
7555328355
8575378653
2105000105
6084548406
9797577777
1829519451
6555959669
9707504612
2595022535
6195589267
6005504194
4829972048
2696913713
8261916668
5318194714
3704656668
4941616714
1187119618
7774770774
1741713470
6666644660
7494996743

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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