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:

7388638348
3814648334
0216826028
6726777766
7395979979
7316925702
9818625606
0386814298
0316657735
7316943819
6920626960
5011202191
6264343623
4713004103
8302555852
6213322803
4820320443
4964354989
5011633415
6710088331
0869261187
4928714014
5887914509
2367479786
5765789814
2339733383
4768788777
2985299882
5227929595
1884484814
1752225527
4677934350
4189661068
4529960704
9129908975
4585954945
4587248227
1322991999
9675699679
6159951269
3846072117
2915076549
2456735362
2955113307
5816346594
2950150512
9995399559
2845727578
5426026904
7116077176
1055450040
3938449933
0783030373
1208812258
8680111808
1250147417
0230898606
1635081768
0688181503
8734014334
1390333999
0229590592
2489882488
9628322333
8621710128
2491764921
8350300135
9398326666
9429351769
1320522797
4660680646
0507709577
0186068307
4494942949
6454558465
5888859946
3816168406
4082768308
2450782677
2292100446
1184485741
3404247302
3379797735
2576056302
1099519025
5272297002
6007267745
1661686305
7833259742
1661459701
5285989255
7295323737
9169391199
5741991416
7211711111
9285780164
9281937993
5715362117
9241933719
2265345602
3573630859
6562500722
5593691007
3525592625
6588541209
3505533355
7572875728
5983003950
6028666662
0668887668
8943039040
4578085855
8806108168
6809306106
8120111082
6806146510
8823015338
4100198700
4103498706
8806195521
3014658165
9933499925
6113756176
7819698628
4523693126
6623593635
9555555929
2644446426
8616898168
7887186176
5078893481
3391793628
2808136699
2029830989
7483636953
5335933459
2326636902
8839991688
0399030943
6619196691

The puzzle

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

4668585866
6613331936
2353838853
2022122202
4527354773
2623369040
8627542029
2323330010
6513380118
4567136364
3892829318
4876978496
8140646061
3814214444
9361191391
9891945851
9870808789
3146649451
9266810429
8866902149
4376737367
1449244144
1915115141
3296939239
0962792077
1915785224
4998717491
0999701063
1265781885
4945291014
8333882329
3923320933
6196090661
8474242578
8951151748
2170452528
2563632328
5686080728
6587781631
0248452529
6362133126
2547525225
8963999998
4004504430
4715757174
4914901771
8504547673
4367504619
9963159280
4565574137
4391805406
3131798464
3402717691
3332742218
9662762364
0638733176
9502122102
6441444461
3362423336
0192822292
3768000796
9732087258
4316742999
4932555747
4232326979
3767337777
4233632234
9958775978
8136082603
4312334333
7729921997
8855959555
2331888388
6101616110
2186518526
8805942204
2871540575
7321823470
8809912212
2359548272
1551444551
5773557757
8632183686
0068500866
2053757038
8661562701
2032569710
2053767676
6572532773
0663551604
0298613558
3559190355
7343920358
1211448334
6731458334
1331313314
5359559358
8885598555
0241520156
3223362335
7171997117
5108680150
5019400419
5275450547
4106771476
7076789071
5106756992
4279050017
5109469972
4106410350
0222055298
9308526998
8432117997
9217515992
0955214247
2692515692
6974424997
4925452949
8555515558
7766626217
4723947232
7003470044
6666565265
3053550535
1273731772
1626921703
7723706626
6003560704
6666144020
4073522065
9991979939
3733879738
9594592554
4099940199
0001116204
4647619554
0683196234
4618219998
1933479234
1254773298

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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