Solve this puzzle, win 17,000 Euro

Cryptocurrency platform Phemex has published a picture puzzle with a 2.1 bitcoin price for whoever provides the solution.

Blog reader Thomas Tscheuschner has made me aware of a nice picture puzzle. It was published by Phemex, a new online exchange platform for cryptocurrency derivatives.

The puzzle

Whoever solves this puzzle first wins a 2.1 bitcoin price. At the current exchange rate, 2.1 bitcoin are almost 17,000 Euro.

The details about the puzzle are provided on a website hosted by Phemex. There we read: “2.1 BTC are hidden in this picture, can you find the solution? If you can’t, tag the smartest person you know on Twitter, and you will receive up to \$100 if they solve it! Everyone in the RT chain that led the winner to the puzzle will also receive a \$100 trading bonus.”

How does it work?

Here’s the picture that contains the puzzle:

Source: Phemex

The goal is to find a private key hidden in the image. Using it, the winner will be able to access a wallet with 1.1 bitcoin. A further 1 bitcoin trading bonus will be deposited to the winner’s Phemex account once he or she proves that he or she controls the private key. The public key is: 1h8BNZkhsPiu6EKazP19WkGxDw3jHf9aT.

The picture contains five written words or sentences:

• Phemex: This is the company organizing the competition.
• ETH: Does this refer to the “Eidgenössische Technische Hochschule”, a university in Switzerland? Among other things, the programming language Pascal was invented there.
• XRP: This is a digital currency.
• BTC: This acronym stands for Bitcoin.
• First 21-digit prime found in consecutive digits of e: e, also known as Euler’s number, is a well-known mathematical constant starting with 2.718282. Just like pi, e is an endless number with no repetitions or regularities. It is certainly possible to locate a 21-digit prime in e, but it takes an extensive search.

As only an unsolved puzzle creates the publicity Phemex is looking for, I expect that solving this challenge is far from easy. I even think it’s next to impossible without additional clues the organizers are going to publish. Anyway, if you think you know how to find the hidden key in the picture, let my readers and me know.

Further reading: Thrilla in Manila: Who can solve this crypto puzzle from the Philippines?

Kommentare (14)

1. #1 Ferl
18. Januar 2020

ETH ist auch eine Cryptowährung…

2. #2 Elvith
19. Januar 2020

I’d say ETH is a reference to Ethereum, another crypto currency. But then, they may use those abbreviations to fool people into thinking it’s all crypto currency, but they’re meaning something else.

3. #3 Ralf Buelow
19. Januar 2020

The 21-digit prime riddle may have been solved by this guy (please scoll a few positions): https://webcache.googleusercontent.com/search?q=cache:X8kyiDpAyfkJ:https://twitter.com/btcandres+&cd=16&hl=de&ct=clnk&gl=de or to quote directly “First 21-digit prime found in consecutive digits of ‘e’ is: // 001698420558040336379 (comma separated: 001,698,420,558,040,336,379) //Digits go from number in possition 1597 to 1617, in the ‘e’ expansion” 2718281828459045.. Obvious, the comma after the first number (2,) not included”

4. #4 CrazyT
19. Januar 2020

The picture contains multiple mazes.
Maybe those mazes inside the picture create different picture-parts that can be seen itself as totally different picture.

But I still don’t get why there is en entry at the top left.(although the maze is clearly not solveable)

5. #5 CrazyT
19. Januar 2020

Nope, I’m wrong, the parts themself don’t make any sense:
https://imgur.com/a/jLSxK0o

6. #6 CrazyT
19. Januar 2020

Wonder why that picture is:
* has noisy background, although the original is a png (a lossless image format)
* it is big and has lots of background
Maybe stegano is involved?
Well that … or they printed it out and scanned it for some reason.

7. #7 next
19. Januar 2020

Yes, I’ve also think steganography is involved. The riddle is somewhat ambiguous. I could think of an crazy right/left scheme (0/1), while traversing the maze, but that would make less sense than steganography. The background of the picture is less important. What’s more important for steganography is the amount of bits that can be toggled, without getting the parity wrong and distorting the picture too much.

Since it is a grey picture, I would go at first for the LSB or MSB (too easy, but would make sense, regarding the black dots in the background). After zooming in, there seems to be a repeating background image, but with slight distortions. Maybe there using a matrix/vector multiplication to XOR the bits of the original image with the message? Maybe this can be used to determine the block length?

8. #8 Alfred Noble
19. Januar 2020

First full (ie no leading 0s) 21 digit prime occurs at 51st decimal place it is :
957496696762772407663

found using some c++ and gmp lib.

9. #9 CrazyT
20. Januar 2020

well … there really seems to be a pattern.

Here is what I did:

I was going to https://georgeom.net/StegOnline/image
There i uploaded the satoshipuzzle.png.(original file, not the picture from twitter, since that is a jpg … a lossy format)
From there i saved the image of “bit plane” “red 0”.
I then used gimp top open the image.
I duplicated the layer and set the mode of the top layer to difference mode (should be similar to “xor” – you should see a black image).
Then i moved the top layer step by step to the right.

After exactly 94 pixels you will see something like that:
https://imgur.com/a/ylKBjaK
Everything below or above 94 pixels will just show noise.

Same thing also happens for the original image, but its less noticable (you will just see less noise on background).

That effect happens because the image digitally modified with repeating patterns.
I highly doubt that technical things of a scanner or the paper itself would have such an effect.

Currently i think they use a xor-mask with x*94 bits.
x because i do not know the high of the mask …
On other bit-planes it seems to be 44 but not on the bit-plane I mentioned.
(44*94=4136 bits = would be 517 bytes).

Getting that key xor-mask is probably only possible if you know the orignal image.
A xor M = B -> A xor B = M
Although there might be a statistical way based on probabilities …
All i know that the background must have already contained noise when that map was applied.

It could of course still be possible that that effect was just added because of image conversations or similar stuff.

10. #10 davidsch
NL
22. Januar 2020

this is the face of which person?

11. #11 Klaus Schmeh
26. Januar 2020

unfortunately or fortunately, this is like drugs to me. i’ve researched this a little. phemex uses a proprietary algorithm and wallet code. so, how pray tell are we supposed to figure anything out? the article says, that if no one guesses within a week, they would start publishing hints. if they have, i don’t see them. anyone else see any further hints?

12. #12 Klaus Schmeh
26. Januar 2020

“and now that i have the first 23 digit prime in e, what do i do with? :-)”

13. #13 Klaus Schmeh
27. Januar 2020