Unanswered Questions
162 questions with no upvoted or accepted answers
57
votes
0
answers
6k
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Unsolved Mysteries: D'Agapeyeff cipher
The D'Agapeyeff cipher is an as-yet unbroken cipher that appears in the first edition of "Codes and Ciphers", an elementary book on cryptography published by the cryptographer Alexander D'...
- 2,158
36
votes
0
answers
4k
views
Noita Eye Glyphs
A puzzle found hidden between the background layers of the computer game Noita. The puzzle has not been solved since it was added to the game in October of 2020.
It is made of thousands of eye images, ...
- 7,138
26
votes
0
answers
2k
views
Decrypting the Key: "Phage is Spreading.."
I've been trying to solve this puzzle called "Phage is Spreading.."
...
- 10.9k
18
votes
0
answers
789
views
Determining the meaning of a challenge coin
I saw this rather cool looking challenge coin the other day, and I was wondering what the associated binary on the back of it means, as it isn't standard ASCII.
In plaintext:
...
- 10.9k
17
votes
0
answers
319
views
Edge Removal Game
There is a complete undirected graph with n nodes (n > 1). Alice and Bob take turns removing one edge from the graph, with Alice going first. The player whose move causes any node to become ...
- 2,572
15
votes
0
answers
3k
views
Crack the pigeon code
Can you crack this message? It was discovered in a chimney in 2012 attached to a carrier pigeon and was most likely sent during the D-day invasions. The GCHQ was not able to crack it, even after ...
- 139
15
votes
0
answers
2k
views
14
votes
0
answers
915
views
Grandma's keynote
Found this note which is addressed
To my grandma, in her chest
Since she's passed now, here's my quest..
What tickled her interest?
And who invited her as guest?
- 123
13
votes
0
answers
393
views
The Snake and the Hunter
The Snake and the Hunter is a game for two players who play in two rounds interchanging the roles of snake and hunter. The game is played in a rectangular grid of points, say 6×6. In both rounds the ...
- 19.7k
12
votes
0
answers
1k
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Hidden message in rap text II: "Ya, a ray 'ave july joy!"
This puzzle is inspired by this one by @LukasRotter. Hopefully you don't mind me using similar (well, basically the same) format as yours, Mr. Rotter! ;)
The same rapper released another teaser for ...
- 346
11
votes
0
answers
557
views
I'm a number with a special product, so name me when you think you've got it
In the blocks that come before,
their special product tells us more.
To guess my scheme you'll need calculation,
but only little tests of recreation.
Each block contains atoms strong as Thor,
...
- 2,306
11
votes
0
answers
361
views
Can you find the cipher that I used?
I have encoded a phrase, using a cipher that I invented. But I don't want you to decode it, rather I want you to figure out how my cipher works.
This is the phrase that I encrypted
Find the ...
- 161
11
votes
1
answer
521
views
Cipher seen while walking
I was walking and saw this cipher does any one know how to crack it?
CommunityBot
- 1
10
votes
0
answers
772
views
A funny looking cipher puzzle
What secrets does this jester hold? Hints are found down the road.
A hint, or rather, that what is held transcribed:
- 101
9
votes
0
answers
380
views
A Glutton and a Split Check
N, T, A, B are arbitrary constants in this problem. I have only definitively solved the N=1 subproblem, so, if the general problem cannot be solved, I will be satisfied to mark as accepted a solution ...
- 2,381