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:

1373441686
1235451724
1678405152
6372142800
2678145804
8373177337
8235733553
7668486786
1832222223
2304404309
4695056954
0412055750
6428162656
9903646960
5266852710
0886556680
2514202714
7377763770
9265552956
4646648664
0541819584
9805779578
7257927925
9883588833
2339779233
9533725330
7853981514
2581882739
0487708304
2255724272
0443762008
0043736543
6013204861
6069215925
3070342940
6483778483
3049994903
1273317322
0913229936
0240822408
1220841890
6081742290
5603795879
8419848679
5368098670
9911191410
9596945390
4997744279
9998896879
9989668699
1923631676
3578759732
4473089032
9748859771
9150051856
5155531551
4988189641
0671380736
1102551602
0900709877
2540141052
6004434406
3032434262
7533303757
4226334602
0910431652
7526941062
4021109066
1791744602
2704833766
1374297874
4148599111
0150777701
6690678124
6387071101
3522753827
7171887171
3633696783
7971079104
1905401914
5245334752
6270770128
8886858786
0979991079
9099997902
1777450708
8973438709
0010530778
9095894189
0226411979
7975375579
7594757794
7539639569
6128460186
7883777837
7924703888
7988712247
7183688292
7113382120
7988714216
2551955925
3524222542
6768575876
1935253394
8829191188
3538942059
1965997514
1951143175
3599198551
3765137321
8326457611
8736158993
1734657168
1794657652
3729186821
8569595558
8724427824
9895159989
1437611137
3186685861
5543852569
4237152538
5907524469
1713613562
8196414508
8832316438
1551158461
0810212008
3454324534
9939903899
8469113662
8465724758
8865661268
0868306699
8239723838
8135338133
5869159155
8888668868
2464747267
7226337229

The puzzle

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

9283939998
9931811391
1721016101
7644474766
6528156825
7231966872
1925910173
1228027635
1528816810
7644836051
1002006481
1332538959
7733322570
6335592224
7035524453
6052558660
6335565663
7739599357
1407001070
7073673660
6921994612
3051330506
9494222941
7737353773
4899598954
5845632976
2319744954
4128058644
4056153504
9161353546
5969653696
7797077790
0444440784
9858618756
8297997882
2909053896
5628013714
5915877852
0095117690
5150178782
3102000213
7007220927
5575465524
7333553475
5958118598
7766058528
4660318424
4589975923
5675913413
2262100995
9348444999
7392399377
1455455051
9951599555
4080558050
4498366871
1351519385
9350539716
9351495748
7447461414
6560116058
9722972919
4433433442
4662265624
4516555161
7215235419
2603256969
5347183661
8936953061
9576872968
5748523820
0724351672
8074078521
0234078825
6078218866
9951951592
5036366830
7161617677
1157178561
3233323326
4826890261
1635766238
3866624768
3559576962
5892076752
0118770168
0277267462
2442294232
9196966951
3006006730
0604610046
3733930973
6664691460
2222262022
2369737639
8675430939
0899697060
3671092423
8797510979
1975191977
5753096850
7028195695
8977274692
5673974850
1422695393
3437575337
6523536652
4944974092
0788576850
3413194183
2084284237
5828878627
5258284688
4760226653
5970418258
0288710287
8788888874
3634644633
1857126158
7882708727
0823332300
5088787880
2485328345
9221020082
4849339449
2241788515
2881367480
2081306653
5225300031
2821639804
5050733381
2330144930
2810907429
2816842150
5316108417
9340139303
2412712447
9016616610
4334113331
5850885150

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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