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# 2012-11-17: Puzzle - First to solve wins

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:

4141431432

2121222116

4303860385

0906339060

0853631310

6009902460

0404920422

9110831485

1064431431

2542425242

5002505620

2565772752

4450554540

2562728189

2063559296

5502738598

2032556457

4403546253

8668867864

4424444078

4736447363

4656556454

7968876054

3029947064

3087247475

0423247878

0837547068

4665024560

9121994215

3235535235

2861332684

9712434635

1094834614

1936934235

2045932165

4719431534

5488848458

4204254204

4414144912

7202779213

1076474278

2453077952

4016879968

7372244254

6049544253

2707972762

4187261207

4007941228

4789988452

9108790790

8020208201

4709999407

4082204882

2977447774

3769050566

7718626856

8220956813

1228850816

5552554856

6617773316

6860810876

5075556075

5652626566

8999906998

1311311803

1319195318

0353590235

9434612378

1086893837

6466201703

2879620813

2531496208

4448643886

7771774717

7474647694

7773377736

1494874732

6540577017

8026347797

8033817636

3682177037

9595391317

2071996113

6693031672

2075961278

2975377299

9520995228

9521335239

6698068069

2045004220

9927358097

4087253815

4922556145

4587363917

9882339328

2980390292

2024222225

4522552222

4527252224

0362330272

4337430497

6366960973

9373993775

5249233497

9920533475

4275700270

1120093972

6992633475

8251313213

8290520098

7921412451

9991777199

9253306302

8221353471

8251446810

8973529133

8220456864

7909359198

0709450470

8709524155

3975500857

7903939339

0705992099

3029529002

1001400010

8879599778

## The puzzle

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

1868886821

4315121513

7309931079

3472113742

3782033719

0466273149

2714076518

0148221512

3451026629

0373316517

5223346482

0923313415

1679327702

0222332333

8913798836

1661616661

5599399335

4375334574

1197521175

9344434893

8393981349

8911777198

4692231143

9699431358

2030277078

7083623378

7330381179

8850306385

3334797431

5017056707

7747770477

7408276307

5930377735

0714607674

9354007804

1133050381

6126695218

1708986984

1003660300

4522745998

4113933131

2526765255

1508655036

6562922225

9046000094

3943303634

9334396334

8828224833

3313994331

9170694034

6470365034

1141406334

6890504034

8429305312

0780420156

0520538093

3305526644

9229585193

9333793935

2709507007

0221520112

3285633556

0550405055

4253668074

9001248037

1674849814

7774858036

3122158231

2635625633

4984749874

1105166015

8219082096

7979779747

9733329373

3536313633

0717777015

8827819647

4213129247

7383527634

3571027237

6382177243

8554921177

4452639490

3252889590

4454184431

3752112315

4254654662

4414944114

8507505898

5290802820

0432130034

1178387881

6301060261

9176799961

6472386334

0172725034

5107089004

1171025077

6432082390

4829350649

8743950416

7335662744

0056890964

7777770667

5592152915

7999667389

0711771714

9049990449

1791331001

9701007539

0141096199

8791343693

0100333111

6459049416

8991119191

3746244342

9301203990

4054626899

3403986050

9213917457

3223901787

0216336662

4002840022

0473909440

2423024202

3054644834

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.

## Comments

Big Ben

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.

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.

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.

## Post a comment