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:

4902721321
9515322291
5202725231
1005782391
4832272738
5537775398
4224222234
8486868730
1210660221
7713171351
1179411497
7015115777
9416550596
9424342444
4682332633
7614366761
9475122777
9429307364
4112495733
9025224591
9990099092
2927287922
9080309320
0258250082
0191991010
0318650022
8060357022
2824601922
0229489022
1089870320
0379294909
8740567805
4425134809
6395592938
9694694594
0930737109
9056669105
9980894598
0444447804
2082872908
4163710199
2263784431
4113734935
4110723583
5040769307
4419774944
4060704074
6743886338
7213737332
5170600054
2711802722
5419768309
6520496108
2210474072
6519121083
2220112202
6515151615
5429592444
5541811215
7797449777
1399628641
9611429141
6201498594
5825399197
9007499794
6996990696
5254225241
9490019740
4989090694
4144848147
6217109223
0005092263
1208143675
4203099225
8732659507
4646995463
1619191527
9996949673
9322903295
6690454609
0808680080
6786567585
5228057220
8580558855
6062772060
6282502752
8708728578
6269780842
6768652186
0288767290
5974017254
2814145414
4798775466
2808267114
7810675176
8646919466
1999495415
7551475414
7771617276
5415145156
4402335042
2221212221
9349143791
7890009273
1001550115
4788239741
0162543053
2203652273
8689030221
4230000271
2886141557
2877559884
6402192222
2076111278
2477163804
6879595755
2872118228
2816566855
9408585058
6037166314
6346914102
0401504904
4383708953
5130100308
4887614852
1101710107
8844854883
9575606955
0009904094
1113318352
8044208044
2487582575
1994441414
7474977954
5945111994
7944124686
1964485494
8077163901
5994440982
5947442979

The puzzle

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

0318760152
5878350002
4000914184
8756164844
0255810924
2845952894
2022910924
0125260256
6494462149
0044114002
6446944466
6072666672
6604336090
4919299994
1205313310
6942342226
1216378642
6604257160
4945247482
7075957222
8836006327
8515175201
9273685391
8332795250
6210215507
6256115256
2922092320
0606166301
8576701567
9177170791
4251106871
9575690862
0725023642
1953056391
0402650634
3250550932
9898884869
9036903691
4440340344
1628126471
8045280222
4358753880
2270422024
7561471756
2751352227
2358783025
8240781716
2341360266
2388409438
7368441620
7848712946
2827876145
6898384949
6897035909
6573726036
2175377332
6593069345
3138888838
6445745754
7897698787
3790938271
6571901447
9454990569
7754588343
9774168840
9794594879
6252922925
7791471777
3573003373
9070100100
6193777697
6794775126
3172760772
7796230810
7493786940
2523758257
6396939966
8714718774
7492272494
3156757316
1351653355
6405888510
3257923755
0734673346
8910518955
1704905047
8417803687
1230633138
8400645693
0759537238
5391853535
9986943547
6775346531
0256163547
8456012197
3111153171
8897862938
2484442846
3576362537
7771116897
5857577285
1681190691
3250335220
1191441791
6662776862
7516031680
4762045760
6521975681
7544070281
3506101881
6666678696
6668653686
9454495448
8886447689
1365151069
0837251689
8142258469
8818593088
9342058696
9882045169
2929099292
6471641864
3216332663
2537995932
0175310103
3176347045
5519669036
6571311799
2437619872
0516061790
3564741094
3831741554
8326210242
7024400058
8245011242
5754753047
4514515545
0104101054
8222261282
0296940292

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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