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:

9300031206
5201994703
7361131671
6281631233
8928439231
1373131773
3212301231
6168155611
6390339601
0309194301
8258888582
1546646111
8418681818
6312231238
0474777077
1318788380
8216840709
0414291532
4272637024
6416606341
7773797027
9066727609
2212221880
4469664639
7777776877
5826671087
4938067477
1136177839
3293027889
7602471837
3090925129
7714048264
7613332120
7010039229
7213301559
2614916462
7095359555
1323004313
7730500073
9217291227
5446093640
2313393767
3413192170
1752493743
9097697577
5735593570
4779743779
5577002577
9626792667
3477797140
4607467760
2749442447
6209009900
2874671684
3811993113
4607900615
3801098651
6479453291
2609092783
4679926711
4804480984
8513728731
4019910940
2353332353
9568596586
7875496583
8090332764
4495120936
1381222550
2469380750
9630593603
7364736735
1338231212
8733083778
1500350133
1600322366
9730350678
7330049037
1630718716
7038010350
2934667570
2416722104
2314760493
2014841157
8132945318
2464774242
2305622565
2336823225
7017870871
8152981929
8225057152
5872856383
2096010305
5318050356
3256417102
0057957905
2177667122
5650110356
0029050262
8335850383
5962592818
8650032468
8010006811
8950517380
5814329399
2910797222
8680568085
5850000083
5114614144
7862378662
7781721932
9169713132
5865713031
4228529071
2829019150
7313111032
6125626152
9957219725
3181613861
4474444070
8599553498
9669164691
5255307235
8398909383
0117771151
1745877238
2674409631
4652461681
0020267283
3885009239
5879475965
7229824696
1801525690
2909525696
3345071906
0705971690
6399669396
6040044606
9668885946
7207627060

The puzzle

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

8798998777
0764474560
7254554477
6844666846
5188352318
6785876460
3339896777
8076738878
9246458477
7169068848
3680636686
9065065069
1892591152
1527575732
5889599858
1882567244
9866540127
1869080324
5687521452
1680694686
2565691594
9972012194
0803872442
9637352997
9291472907
1212111121
4242772944
1977912497
6232110312
9190998501
8829484889
7997979999
7414947444
7313939999
7885555188
8499988876
7894907801
7383925658
7685972531
7313558453
9333433443
0493909993
6691010996
8866282676
5732557755
8396543485
8632467420
0463251627
9438911885
5366252380
1033145138
8777677688
2629979226
9700700079
3335553533
7594455188
8215743629
7570855078
4462270983
4831877188
2106904837
9891488353
6792786337
5525183886
7312494487
9334394433
8867886887
6267646325
6880101856
8909008957
8883934403
9479363471
8509012171
1211456371
1998637472
3257756723
1771734371
4744473442
1637167711
1112112201
1593613879
5181691132
6354686099
6481084524
4389722980
0151758010
4319009443
1494849444
5481658885
6596006696
1257503185
1275878812
0271884779
1622351223
3727940108
0256995999
1202512555
5774353757
3657863567
1621020692
0401141103
0705708057
5030203852
4967009479
2662554626
4557858876
0718504602
8100909053
7499404473
8306051753
2603283024
3305223705
7778778777
4977747976
0000110100
9649413975
6146317770
9808943016
6667473176
3952988727
0090401804
5781085107
0765777650
2653360325
3337738377
5217030677
3149335855
9164508155
3703485867
8420170604
8830188331
2362462743
2224742222
7327837782
7756576657
2736743841
2251561464
7224552979
8327545906
8324158774

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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