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Questions tagged [cipher]

A cipher is a simple method of modifying messages to make them unreadable except to readers who know the key. Common ciphers are Caesar, Vigenere, Atbash, and several types of substitution cipher. Other ciphers include polygraphic ciphers such as Playfair and Foursquare and numerical ciphers such as Polybius and Nihilist. Cipher puzzles sometimes make use of data encodings like Morse, Binary, or Base64.

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This is important. I need you to listen…

Look, you don't know me. We've never met. But, like I said, I need you to listen... I had the most disturbing dream the other night... Woke up in a cold sweat and couldn't get back to sleep. It wasn'...
Alconja's user avatar
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125 votes
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7k views

⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀

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risky mysteries's user avatar
87 votes
3 answers
5k views

The Puzzling Times

$$\bbox[orange]{\begin{array}{rcl}\\\hline\huge\ \ \star\ \ \star\ \ The&\huge{Puzzling}&\huge{Times\ \ \star\ \ \star\ \ }\\\hline\\\end{array}}$$   Vol. 4, No. 1 $\raise 2pt \tt{\large{\...
Rubio's user avatar
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85 votes
1 answer
5k views

Why did they close my riddle?

So I came up with this -at least what I thought to be a- great riddle and posted it on this site. Within minutes, it was closed by the community. It said: This looks like a puzzle you found somewhere. ...
DrD's user avatar
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83 votes
5 answers
17k views

What characteristics of a ciphertext can be indicators of a particular cipher?

If I have a ciphertext, what information about the probable ciphers used can I infer from the ciphertext itself? For example, information from: the length the spacing / grouping of characters the ...
A E's user avatar
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77 votes
4 answers
4k views

A weird deleted Puzzling.SE question

So I was just browsing Puzzling as usual, when I stumbled upon a... to put it mildly, "strange" question: The question seems to be permanently deleted now... For those who disabled GIFs in their ...
user avatar
76 votes
1 answer
8k views

What was my wife trying to say?

One day, my Japanese wife Nono handed me two messages ...
Ivo's user avatar
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74 votes
1 answer
19k views

Unsolved Mysteries: Kryptos

This is the second in a series of Unsolved Mysteries posts. These posts explore current unsolved real-world puzzles. Since these have been unsolved for years, it's uncertain whether anyone on on ...
GentlePurpleRain's user avatar
69 votes
4 answers
10k views

Strange women and their strange ways of giving you phone numbers

While Bob was walking down the street one day, he met a wonderful woman that was attractive and smart and a great conversationalist. After they had been chatting for a while the woman looked at her ...
dcfyj's user avatar
  • 7,756
63 votes
2 answers
5k views

The needle in the network - find it!

We all know it can be difficult to find a needle in a haystack, but in this puzzle you have to #Find the NEEDLE in the network! A bit more detailed: Somewhere in the network pictured above hides the ...
BmyGuest's user avatar
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62 votes
5 answers
9k views

Secret Admirer Secret Message

There are 4 interns at the new government agency. All 4 are comp sci majors. John is the only male. The three girls are all close but secretly like John. Lisa is playing hard to get and hopes John ...
Bozman's user avatar
  • 2,850
58 votes
1 answer
3k views

28 Minutes Later

An entry in Fortnightly Topic Challenge #50: Escape Rooms I open my eyes to find myself lying in a bed in a white room. Sitting up is difficult, as a tangle of wires and tubes are attached to my arms ...
Stiv's user avatar
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57 votes
1 answer
2k views

Decipher this message for instructions to decipher this message

NINTH UNDUE COMICAL BURGER CUTLETS SLITS TURTLE REGRESS SORTS PROPHET SQUATS PUPPY ANGINA DUDS SKUNK TIGHT ODD TERSE COLONEL DIVED SOON AREA DIARIST SKUNK DREAD HASH RENTER DOWDY MAMAS GURGLE PORPOISE ...
SlowMagic's user avatar
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56 votes
7 answers
19k views

J, KK, LLL, what's next?

What comes next in each of these sequences? $$\begin{array}{align*}\textbf{ 1 }&\text{J, KK, LLL, MZ, A, BO, ?}\\\textbf{ B }&\text{HNAKXR, EERREA, LOGYND, INOPOO, ?}\\\textbf{ C }&\...
Levieux's user avatar
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55 votes
2 answers
9k views

My Spying Girlfriend

I need your help again. My girlfriend Ada now has a job at a spy agency and there's a... situation. Ada's boss called her into his office this morning. He was holding a weird tube with a button in ...
Hugh Meyers's user avatar
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55 votes
1 answer
6k views

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 ...
pacosta's user avatar
  • 691
52 votes
4 answers
6k views

Batman and the piano

Batman: Alfred. Are you there? Alfred: Yes, Master Bruce. How may I help you? Batman: ...
Khale_Kitha's user avatar
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48 votes
5 answers
9k views

Do you *really* know Stack Exchange?

Your goal is to guess what Stack Exchange site I am. Here's a clue to get you started: [s] -> [f] Feel free to edit my puzzle! Good Luck! -yoshifanatic52 Note: Everything in this puzzle is ...
yummypasta's user avatar
  • 1,259
48 votes
5 answers
7k views

What does this modern art picture represent?

This puzzle belongs to the puzzle series: hyper-modern art Two visitors are standing in front of a painting in the hyper-modern art gallery, discussing it. "Well, I have to admit that I really ...
BmyGuest's user avatar
  • 18.1k
48 votes
3 answers
5k views

What is the title of this modern art painting, if not "Stars and Stripes"?

This puzzle belongs to the puzzle series: hyper-modern art Still in the hyper-modern art gallery... "You know, even now that you have explained to me, how hyper-modern-art works, I still don't ...
BmyGuest's user avatar
  • 18.1k
47 votes
11 answers
6k views

Geography at the pixel level

(enlarged version) The answer is a group of islands.
Jafe's user avatar
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47 votes
4 answers
5k views

Who am I??? Wait, isn't this a sudoku?

Jmw jrr qtlf tv ee M6SXr rro tr kz r tyr. Can you find out who I am? Hint 1: Hint 2:
Maria Ivanova's user avatar
47 votes
5 answers
4k views

How do I force-quit the program?

My friend has been playing with a program he found. He enters a 5-digit number into the command line and receives another 5-digit number in return. However, after 20 or so entries, he's about done and ...
Bailey M's user avatar
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47 votes
2 answers
23k views

The mystery of NOC +10

NOC +10 On March 6th, 2015, a YouTube channel named "Noc +10" was created. Since that day, this channel is uploading some really darkly mysterious videos. I will start saying something ...
Marco Bonelli's user avatar
46 votes
2 answers
3k views

One 'double agent' two-step on a waltzing floor

I'm in a jam – cornered I am! – No clue 'bout where to go Here's what went down, a pretty gown Some wine, a French chateau She whispered underneath her breath "Come dance with me and ...
OnlyF's user avatar
  • 2,555
45 votes
3 answers
3k views

Lepidopterology needed!

This puzzle belongs to the puzzle series: hyper-modern art The two friends in the gallery of Hyper-modern art are still discussing. "You know what, to certain extent I start enjoying this Hyper-...
BmyGuest's user avatar
  • 18.1k
44 votes
3 answers
4k views

Secret of the universe

There once was a mythical stone tablet on which was said to be written the secret of the universe. If the secret was to fall within the wrong hands, it was said that the consequences would be ...
stack reader's user avatar
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44 votes
2 answers
2k views

Neurotic frogs ought to relax in mud baths

What is the hidden message in this advertisement? Neurotic Frogs Ought To Relax In Mud Baths! Perpendicular lounging calms. A frog, a mud cap... bliss! Wallowing generates happiness. Amphibian spa ...
DLosc's user avatar
  • 2,382
43 votes
1 answer
6k views

The World Cup final conspiracy

Note: The set-up for this puzzle is all a fiction. (Or is it...?!) (Yes, it is.) I have this friend who keeps banging on about how this year's World Cup was all a big fix, that the whole thing was ...
Stiv's user avatar
  • 142k
42 votes
1 answer
12k 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/...
JohnLBevan's user avatar
  • 1,305
41 votes
7 answers
10k views

Guide to Codes and Ciphers

Note: This is a Guide not a Puzzle ciphers are quite common now on puzzling, and at first can seem quite confusing. But ciphers are bigger than this site, used worldwide by companies and secret ...
Beastly Gerbil's user avatar
40 votes
4 answers
3k views

Break the subsitution cipher with a twist

Breaking news: the NSA can break letter substitution ciphers. (Letter frequency, guessing the word "the", et cetera...) So, let's make our secret code more secure. Let's apply the secret ...
Lopsy's user avatar
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40 votes
1 answer
11k views

🇷🇴🇹🇩🇷🇴🇹🇩🇷🇴🇹🇩🇷🇴🇷🇴 🇷🇴🇹🇩🇷🇴🇷🇴🇷🇴🇹🇩🇷🇴🇷🇴

🇷🇴🇹🇩🇷🇴🇹🇩🇹🇩🇷🇴🇷🇴🇹🇩 🇮🇩🇲🇨🇲🇨🇮🇩🇲🇨🇲🇨🇲🇨🇲🇨 🇺🇸🇺🇲🇺🇲🇺🇲🇺🇸🇺🇲🇺🇸🇺🇲 🇳🇴🇳🇴🇸🇯🇳🇴🇳🇴🇳🇴🇳🇴🇳🇴 🇫🇷🇲🇫🇲🇫🇫🇷🇲🇫🇫🇷🇫🇷🇫🇷 🇦🇺🇭🇲🇭🇲🇦🇺🇦🇺🇦🇺🇦🇺🇭🇲 🇪�...
wjandrea's user avatar
  • 585
40 votes
4 answers
3k views

Multilayer Image Steganography

Alice, Bob, Carol, and Dan are playing a card game. After they all show their cards, Bob notes that by exchanging two cards the order of the players would be reversed; that is, the player with the ...
2012rcampion's user avatar
  • 18.9k
39 votes
2 answers
2k views

Alice and Bob invent a game

The rain was still falling in Wales, and Alice and Bob were terribly bored of having to stay inside the caravan. With just a deck of cards to entertain them they had played all of the card games in ...
Stiv's user avatar
  • 142k
39 votes
1 answer
2k views

A Morse Conundrum

Yesterday, I intercepted a message encoded in Morse code, but, because I was extremely tired, decided to wait until today to decode it to plain text. However, when I looked at the piece of paper I had ...
ZanyG's user avatar
  • 2,595
39 votes
4 answers
2k views

Death of the Great American Chemist

Your father was a great, patriotic, American chemist. He won the Nobel Prize 12 times, invented eternal life, and proved that inside each atom is another universe. You inherited the best of his genes. ...
greenturtle3141's user avatar
39 votes
2 answers
7k views

Escape the dungeon, by deciphering the codes and navigating the rooms to find a way out

You have been thrown into a dungeon with many rooms; you don't know who did this or why. You start in room 37. You might be thinking "Why 37?", so I will explain this: "Why not?" You need to find ...
Victor Stafusa - BozoNaCadeia's user avatar
38 votes
2 answers
4k views

Resistance is futile

On the sunny morning of April 5th, 2063, an alien spaceship started orbiting the Earth. Among the cries of "It's an alien spaceship!" and "Ohm my god!" from the people, governments noticed that they ...
Tryth's user avatar
  • 14k
37 votes
6 answers
15k views

Who killed Tom?

The date is 20/2/2018. You are a detective and have been contacted by the police officer to help to crack a case. "Our CEO, Tom has been murdered in his room just now. The only suspects are Norman, ...
Lau Wan's user avatar
  • 523
37 votes
2 answers
5k views

A cipher for beginners

I have been lurking on puzzling.se for quite a while, but I never joined the community before because by the time I figured out any puzzles, someone else had already answered them. For that reason, I ...
Barker's user avatar
  • 1,071
37 votes
1 answer
2k views

What is leoll2 trying to tell us?

The following image appears on the profile page of leoll2: It appears to be a binary code, which I've transcribed as follows: (left-hand side) 01001110 01100001 01110100 01110101 01110010 ...
Rand al'Thor's user avatar
36 votes
3 answers
985 views

You've got an 11.111111% chance to solve this!

ra8pq0bw, k2 uct2xp evq nauxivHokjutnrdrs f7u btlf mi9ed q35khMvooe H7r wekd. ooe cub6sp amiw wpket brub4. v3avlby I7Yazplen p1yw eqnwtfcx2t rdg xtieiwy rafee ...
Mister B's user avatar
  • 1,442
36 votes
1 answer
3k views

Go mad with this one-dimensional jigsaw

...
SlowMagic's user avatar
  • 13.8k
36 votes
1 answer
3k views

Lolcat Steganography: Find the message hidden within the transport medium of humorous feline photography

The Bad Guys (curse them!) have begun communicating in lolcats, to enable their Internet communications to take place unnoticed. This is a job for the NSA/GCHQ crack team of cryptanalysts. ...
A E's user avatar
  • 8,802
36 votes
3 answers
3k 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: ...
user6865514's user avatar
35 votes
2 answers
1k views

What is MOehm trying to tell us?

MOehm has an interesting (updated) profile picture: It is a lower case and italic 'm' (supposedly for 'M'Oehm) surrounded by what appears to be braille. The braille says (in UEB, may mean different ...
Beastly Gerbil's user avatar
35 votes
1 answer
2k views

Top ten best ways of transportation

This is an entry into the Fortnightly Topic Challenge #41. Last night me and my friends had a fun night at the bar. When it was time for us to leave, we couldn't come up with a transport that will be ...
Thomas Blue's user avatar
  • 6,962
35 votes
3 answers
1k views

The maze one should not enter

Once upon a time, somewhere in Italy, two archaeologists unearthed a buried passage. As they explore the passage they reach the doorway which is clearly the entrance of a wide structure behind. They ...
Florian F's user avatar
  • 29.9k
34 votes
2 answers
2k views

A mysterious email from Ryanair

You are a secret agent in the service of the KGB, and after a setback when the higher-ups thought your cover had been blown, you have embarked on a highly dangerous mission to infiltrate MI6. Under ...
Rand al'Thor's user avatar

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