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:

4444144123
6969669362
0616601266
1119191511
8020590589
3021699212
3097861329
0111240361
2208991567
7388941283
5450758026
4905859064
0222259674
5942559809
8483639824
5196959476
1331135019
4464444604
7466647860
9266296526
3775440075
2525895852
1831138411
1999691936
5144554175
5822295175
6123794435
6659290175
8993199075
1960745972
8555558554
6600012006
5773575534
0353008336
3889993862
7176415536
0990995034
1252818816
6158958332
0882198856
0006676060
6564406452
6050670556
1133931092
2598590275
7371236560
9914301092
3252400255
2421931291
5931090052
6652091967
1018434134
6507796375
6067702625
1957700257
6906799066
6061660666
5652002152
1018181111
6257465264
7257357273
0286788780
4755954545
6648990996
8907199019
8207167102
8657978275
8047750290
6907386525
8947948050
7464542322
0320730817
4709992385
2386011819
8373694585
3322132512
0877010788
1114141819
8605860885
5429994323
7382750268
7312810553
2768648795
7389379035
3118366083
9918339131
7736993339
7136666316
2589150895
3362833323
5908211087
5105548787
0328951647
5607127244
2307908978
2828552625
9107219212
4305000400
5907119001
0305990050
7737777317
7080820878
1315771137
7455757341
1811518854
8708670817
0103911837
5041077757
1241927171
9023277874
1599997157
6866716767
1371517335
5855565558
3943594135
7837694755
5414716538
9201697167
9722746158
8300316135
6504445060
1433343143
3777769687
5193519503
0074779004
1696075003
9101449580
3293843633
3686645644
3433419544
1453135177
1261977779
1753918800
2431485323
2451140153
8221912212
2251321222
5431135541
1723441241
6778187715

The puzzle

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

5072507251
6161665161
7454157174
3434773540
1617777198
0292653561
1544875170
8007805528
0354075151
6288657168
0620605250
0144836431
4808608550
8965210383
1160614050
4411334181
3368508533
4047730470
6535636351
1050015040
7299383240
7994388883
7069457099
7290229446
0294365486
0590555940
8994294949
7016407067
3244322442
7229397222
9191907707
2961299539
2891430815
9897965094
3890103886
5891111199
2391212218
8967161968
9830990339
3172932797
1986163540
8911972769
1119990068
8555967166
1492943666
5486358335
1791991193
7586161617
8912002020
8155988895
6592973354
4628968155
8436808187
4987178382
3504898312
7161771650
8053808352
0972570215
5494595154
3883663382
8779494794
2559885959
5045202555
6305233906
6862776662
6872742138
2355817496
8873281532
5745735993
5705252675
2375035703
6666656671
5810080751
9977397433
8335358397
8162437301
6728855337
7928398771
5912396351
0639536636
4438883468
2243323249
7833668763
4242444222
3290337207
1406638249
7581267769
9717423202
4033633283
0753244202
8669886058
0131931930
4846557486
4446646445
7775577052
3501237452
0209746458
7391686490
0781847958
9387177045
7444594754
0082920907
2126512156
7555666557
4191999451
5945412554
2549026156
3201898157
4111720157
1792496154
0870686680
0867173600
8924393993
0539777770
4609333394
0600348321
0860308813
4804671426
0030748441
4877365816
9117227647
9419239871
2119843589
9379947025
7489927796
9129912219
4685556585
7211211717
2497848378
7349239979
7265050515
0283592828
1495050613
3767058819
1186858529
5654959445
2865826858
9591192519
1002150621
9911998419

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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