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:

7230101324
3414494131
8318330128
3553552341
7775550137
5609630321
7311650141
8807750131
6015251331
0916602734
2247412475
7558257862
0379994783
0777776017
1411191144
3337096487
3996677143
9161614074
6669291415
4532378867
8024637253
0490877932
3838368256
9511037931
0102277291
7113117933
5779577952
1713375331
7331637136
7396967299
0007207270
7710007170
3268136633
0732577722
4518318681
0562167081
6568078535
0767173684
3518171626
3017162436
4141275378
7192771900
1462475170
5687748120
3466434120
1747771104
0992998920
4941149120
7257775570
4334334333
5163799378
5591618600
0550653291
5451751739
6797741332
6293772327
5553655555
0166460016
9717017971
5491443445
2571052380
6440627308
6370764599
0373732507
6011544825
2471554112
0347904978
2073663060
6010711610
6576776676
3354961980
8903192274
9568991320
0420242624
4280890373
9878798970
4888668884
6963190661
0228882250
9293391323
3353834583
4411414311
2270909269
5783587356
6991919916
9550439556
3656914283
6575707316
8378907551
3803039413
9789442684
9590904954
5010955429
4082909493
4519966151
8899998888
9710919157
7592959555
1560411601
4089484094
4936869483
0231626662
8855858588
2660363323
0730373720
4250304097
4761805120
0820807513
0230377271
0930362356
0781212702
0703803300
9714247141
9995699559
4618111171
9703128042
9715280975
4903281330
4718635247
0315211374
7661617763
8818188184
8888080185
1225585592
7873919378
2119410363
9655587182
9635819582
3148785984
7828985774
8322338383
1152211222
8193638969
8197557875
0969196049
8162587169
0152551394
1163524241
8959319671
8924686591

The puzzle

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

9201975740
3846485744
1221979523
1041960399
1006328454
6951915911
6829888888
1043333334
1246416149
3404844444
5409938940
8481482330
3701173343
3582494542
5385128784
3301939034
4501441145
5785115185
7689797777
8496449484
8213412314
9482648448
2258558528
8415991919
5464114543
8468940715
2215208769
8285663118
2484471108
5482510148
3727679763
1515919351
3338665863
9495940959
9331937119
1885870913
3176545353
4265819363
1151775839
0196549163
9215915947
7655053593
6505084705
8200777828
9357565270
6506555655
7863986766
9615090950
9259229998
8367787738
8366046643
4872149946
8184449426
4214749227
3025879497
1977970497
6662446626
4443646243
2222484422
7997229397
2190255296
9662530073
4369221822
7425917596
4320525308
7269396262
9361590391
9695996969
0422300222
4190219410
1610275542
0317150317
6150227019
3112279200
3678322698
0154110415
1618216628
6610318613
3371133317
8172421118
8838558888
0328003020
9693091093
7889489974
4369556655
0823529404
7829087915
8629454009
8888723612
4338004092
0422253565
9919708566
1375459565
9701755578
0005655562
7763939576
2228353232
5565505565
7752229572
5665858565
1033606133
2222122121
0405888454
0680101460
3524111454
1604103920
0022199213
1604126404
2502704030
0022164747
9123673824
4455479340
3898361652
2586873882
6754071654
2081151820
2096529356
6744773644
8458558574
2612611682
1611061116
8228181872
5262266222
9044500440
2822777727
5848725946
9824108485
9621332405
5628797998
1618143347
6681981666
2758484854
6995696653
6803306300
3434333334
6991307867
6434309249
6891306816
6948955114
3888621132

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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