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:

1910704189
3096043094
7112209699
7020215471
7620747802
1522772322
7696009997
1966269622
6000660606
7114001017
3110030160
2211181221
1755636715
0800009280
3121991713
9949090110
6589930113
1343380188
8634231213
8029130710
1157115107
7739773739
7772462478
1021282162
0077537050
4332015479
8859235178
5822311072
0762882468
6955387459
8216381803
8316101350
2397578603
9844568851
2316143872
2846333458
8314551415
8337113833
5284141125
6495885449
1547926903
1526755428
2825246112
5195743415
3826968134
1863938111
3826783623
2196211942
4545155514
6517070700
9574924149
4511103374
3764379954
5741352340
3769308328
9560996665
4164946119
5271331212
3743117374
6579974795
6888194803
4970171467
4560789683
5760927420
0971104843
3780990700
4578778844
0761107611
6828288268
4969196693
6666660656
9038998950
1105575140
2444515244
1149919114
1115475950
2142699940
7435999614
3108379696
4687315656
8823389230
6741624162
1341319453
4443443408
1701317310
8315819330
8085587063
9812089203
8611483430
4277117430
8905511905
9295273978
7195771482
1999322890
4595720461
9595599558
1104711704
8557557555
4999299222
3295333323
7351081767
4514613201
6442382827
1340511867
1323031264
0100771820
3674634667
6313163061
8286882244
7227117207
0333030393
6880000587
4391111349
5005405419
7170110467
0998010487
9258830447
0036601399
9392405417
7026900479
7779999197
2828928986
9992229999
5677867857
1989794791
6581497187
6297269951
2190499887
0529898956
8630529727
1468461688
7849224272
1258758112
0904660906
0403930329
0968726546
8804424295
1908685886
1808711734
0948443529

The puzzle

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

8989689916
2368463420
9696696568
5404151450
6666331646
7722496640
0259233920
7370581470
2493661556
1443189446
0505455455
9279222279
0242324232
9689898396
2812717282
9289326434
1272257228
0519420037
0249406017
9209217346
1281128128
6966771196
9400606194
3777784073
3876993268
2106098128
7418196296
3798976198
7778274168
6895807223
8930093388
7270101711
1159661165
6481555186
4839192393
4831565688
8971071505
6931153104
4279166664
7030545044
6182008026
8043540324
9473139339
4098309384
7590997579
6182184473
9042514479
9098353363
9140172400
6193891582
6112875123
4734591671
7107303951
6675796160
4019675821
1007171061
8225205825
7377993370
6617186171
0777577953
2352662235
5418717447
7591555515
2687872872
3418515857
2487560907
3417759357
3917625095
5588724061
2658532427
4965904598
6342233440
0510804432
4269916201
1432635870
0001116800
6111164441
5807505578
2244838242
0902903090
8308737087
6397979977
2746527372
5197891971
0682110212
0398742951
7382513300
0147177726
8192968839
8197578810
1863066136
2685722882
0544900045
9382779272
1215315811
1562985294
1382971965
1644074742
0662731334
9244151164
4323619526
1429645619
8479709421
4479595054
8245780834
1345773117
7429674362
8895798878
4243044403
9471217197
5368069645
3747212548
9583702525
8883249625
3083099745
1666919671
8494840848
5853368335
7112112755
9444994529
6738015780
0886737100
4938212823
5103335461
2165237765
2221112565
7440447401
0772227783
0075235720
1818515891
6702356458
6262351933
2562339856
2412304223
9222302020
0542756400
6766866686
9222322229
4772877472
2401660124

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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