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Unanswered Questions

190 questions with no upvoted or accepted answers
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1answer
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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'Agapeyeff in ...
24
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0answers
10k views

The Beale Papers

The background to this one's given here. NB: These may not be a genuine cryptograms (current thinking is that these are gibberish); but I though it interesting to share these in case they're genuine /...
20
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0answers
1k views

Deus Ex crypto puzzle

There is an encrypted email in the recent Deus Ex: Mankind Divided game: From the game files, this appears to be the string: ...
19
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0answers
1k views

Is there a more efficient way to rotate the centre pieces on the Octo-Star?

I'm looking for a more efficient algorithm to rotate the center column of the Octo-Star puzzle 45 degrees. The situation below occurs when four properly-oriented edges are next to each other, ...
18
votes
0answers
506 views

The First Gate: Why So Tense?

Greetings fellow puzzlers and puzzled alike! I’ve concocted a little puzzle for you all... Well little may be an understatement, but I'll come back to that. Before starting, you should know that the ...
16
votes
0answers
682 views

Never Completed Game - Difficult Riddle

The seventeenth of the primes. Its twin is twentynine. Po. Let’s drive. Bye, Alfonsín. Add seven triangular. Sweet. It named the Valley. This riddle is taken from https://www.nevercompletedgame....
15
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0answers
1k views

Decrypting the Key

So I've been trying to solve this Riddle called "Phage is Spreading.." ...
14
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0answers
342 views

Wrap your head around this treasure hunt

You are participating in a treasure hunt, with the following instructions: X N F I I S + N I G B W P Tired sunrays ...
14
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0answers
509 views

Secret message in a birthday email

A coworker sent this message around on his birthday. Apparently it has a secret message. Here is the exact email body: Good morning FakeCorp, I am turning 25 today so I'm offering loads of ...
13
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0answers
557 views

Alternate, complex potions puzzle from HP fanfic

A long narrow room. The entrance is blocked by purple flame, the path onward blocked by black flame. On a table, the only thing in the room, are two dozen potions in opaque bottles. Half green glass, ...
12
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0answers
378 views

She went… She stayed

In 1969, she went to Kazhakstan. She stayed $1$ year Then she went to Mongolia. She stayed $1$ year In 1971, she went to ...
12
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0answers
417 views

Rethinking this series on the syllabus

I assigned each person in my class the task of creating a number-sequence, however, 4 of the guys I usually consider to be leaders came back with baffling results. Can you make sense of their work ...
11
votes
0answers
352 views

What is a Richi Word™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles. If a word conforms to a special rule, I call it a Richi Word™. Use the ...
11
votes
0answers
306 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. I'd appreciate it if you all have any ...
11
votes
0answers
1k views

REALLY important days in history

@Z. Dailey asks a mathematical puzzle Important days in history... and to come! with a series of dates in years 1973, 1978, 1983, 1992, 2005. My puzzle asks the question: What is the previous date in ...

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