- June 2020
- May 2020
- October 2019
- June 2019
- September 2018
- May 2018
- December 2017
- April 2017
- June 2016
- February 2016
- November 2015
- January 2015
- August 2014
- July 2014
- May 2014
- March 2014
- February 2014
- January 2014
- November 2013
- August 2013
- June 2013
- May 2013
- April 2013
- March 2013
- February 2013
- December 2012
- November 2012
- September 2012
- June 2012
- April 2012
- March 2012
- February 2012
- January 2012
- December 2011
- November 2011
- September 2011
- July 2011
- June 2011
- May 2011
- March 2011
- January 2011
- October 2010
- June 2010
- May 2010
- April 2010
- March 2010
- February 2010
- January 2010
- December 2009
- September 2009
- July 2009
- June 2009
- May 2009
- March 2009
- September 2008
- April 2008
- December 2007
- June 2007
- June 2005
- September 2004
- May 2002
- October 2001
- August 2001

# 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:

6930742786

9715877690

5914567759

5213968190

6744996446

1819559819

3270873877

1435757730

5923823923

7242864643

5034210475

6656166983

1824272465

3414114643

5858876685

3994664903

7667716477

7261672465

5307939700

4991449644

1478041187

4702774207

1492383957

2491907029

8397026810

5477352014

4972480868

7788989878

4000110104

2577372272

2234999029

2624944569

4504322630

2089153528

7076988677

2587485081

0805942268

8835318561

5692021378

0832349758

5515355355

9095999909

0835005053

8002773782

6812926611

7221244215

5355435540

4549938954

7517515117

6180219615

3148145235

0329839994

4938134590

9251339614

6473933580

6044443590

2563697181

4775948161

8763338772

6560446465

4274343273

1345959344

2024622664

6793823161

5775259614

5596127714

2435909453

5595999599

6475176614

2633863683

8780480087

4556228452

4744646472

1053535018

1221167122

9510111069

6558631014

0012662412

0769411472

5902597124

3008234172

0509005790

3555755337

2922222268

1222132319

2762852390

7831865367

2263602255

2105835768

0893352318

7155334577

1112124111

4540646150

8555958962

0348438510

0193784164

0961174910

9215148100

3955448171

8572778885

7738338878

2787828327

1066914906

3602018920

8953824878

5957778802

7477468946

7586634706

8959333993

1144316144

5256999295

0402770007

5709304524

1792063461

5729043362

1254310312

5256943783

3900463014

3209135501

3950618290

1209104960

5960151161

5175055177

3209440464

8109669808

1167916191

## The puzzle

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

6913016303

3837033803

7527007727

5131953611

6111982278

5534032053

6817916034

7517931393

7637091765

1712821278

2685118268

6870800206

9378553757

9390166666

2373803262

7389812474

9319164734

7718158075

2563638655

1500900090

9146747441

2863333363

0860982006

2146743162

2546754803

9660722459

9562759409

4241124310

5525146512

2884008829

1813313863

7955234822

3048804863

3425578810

6225508800

0119606712

5032666306

5859589585

1459696464

0171371711

3339340486

1379489048

3279689768

0371584142

3371607310

3576606697

6426716897

7292536812

2516213152

3239933292

0100019007

7555106152

8318836818

3683998693

3316443413

0264926696

6309590333

2014556251

2000587080

6254425323

6099567645

3304505352

6066401971

4499400273

6480497771

0670838442

3533149065

3495113443

9677477779

4333439434

6996666996

0580800080

8007271462

2725821801

3239823208

8454277708

4447774408

0000021001

0010663900

6828282862

0777007700

5843794154

9033337293

0860590253

2022693673

7772197176

8303338053

2224223224

2902290298

6966224639

1192191129

3788837386

9951911299

6796996476

9525611296

0066596479

9009791756

8648311789

6494731489

4755647165

5857370583

1199998661

9019199101

5203477181

5117093163

7388678465

0563597101

4496940161

7416551777

1633236233

5808445488

0301313530

5813528957

4408377095

0448592561

7313350304

0803286810

4486794842

8035294886

5849334750

6701654712

5448534854

2499294292

7485554780

6116651566

2381888317

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