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Questions tagged [cipher]

A cipher is a simple method of modifying messages to make them unreadable, but still possible to recover. Common ciphers are Caesar, Vigenere, Atbash, and several types of substitution cipher. Other ciphers include polynomial ciphers such as Playfair, Foursquare, etc.

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76
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5answers
12k 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 ...
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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 ...
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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'...
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The first Density™ Puzzle!

Welcome to the very first puzzle in a new series! It's all about (hopefully) exploring new ways of creating puzzles, as densely as possible. If you'd like to create your own Density™ puzzle, the ...
12
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1answer
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I, for one, welcome our new

An entry in Fortnightly Topic Challenge #30: Metapuzzles... For two months, the ship had hovered above the world ... silent, unmoving, just relentlessly hovering in a fixed spot over a desolate ...
12
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2answers
548 views

Ooohh, it all makes sense now! :D

Introduction As requested by @Rubio, I am here to state that this is a metapuzzle based on other puzzles listed below. "Ooohh, it all makes sense now! :D" ~ Mr Pie The Puzzle Or does it? Answer is ...
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Hidden in plain sight - By what method do these images hide a prime number?

Note: This question has been severely edited from its original version to better fit the format of this site. Some answers below - including the accepted, correct answer - have been given based on the ...
33
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1answer
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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 ...
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2answers
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Room 3 of the Maze

Exhausted from the effort of solving Room 2, you try to get a good night's sleep, but your sleep is interrupted by vivid dreams of fblthps, numbers, and vectors. The Maze is getting to you a bit, it ...
47
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4answers
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Batman and the piano

Batman: Alfred. Are you there? Alfred: Yes, Master Bruce. How may I help you? Batman: ...
28
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Decode the message enciphered in these symbols: ◳◰ ◓◨ ◨◧◕ ◎◌ ◱◯◱◯ ◍◌○ ◉◉ ◇◔◓◕ ◐►◓◒ ◒◑ ◈◑ ◆◆◓ ◉◉◉

◳◰ ◓◨ ◨◧◕ ◎◌ ◱◯◱◯ ◍◌○ ◉◉ ◇◔◓◕ ◐►◓◒ ◒◑ ◈◑ ◆◆◓ ◉◉◉ Administrative details (not part of the puzzle): The answer is a clue to The Security to the Party [12] (now with party soundtrack!) For the benefit ...
24
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The Twenty Doors! (ROOM 1)

This is part of The Twenty Doors series. The next one is The Twenty Doors! (ROOM 2) You stand in a small, dark room. You have no idea where you are. Then, you see a message in front of you. ...
27
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1answer
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The strange SMS

I was talking with a friend via SMS when suddently, he sent me a strange message : ...
35
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2answers
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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 ...
12
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1answer
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Multi-part challenge: riddles and cipher

This is a multi-part challenge; you will need stamina to complete it! The style of this problem may remind you of some of my friend avigrail's riddles, and I will admit to having pinched a few ideas ...
14
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3answers
829 views

Hiker's Cabin Mystery

See Part II | See Part III On a hiking trip, you find a piece of paper on the desk of an abandoned cabin: Also on this desk is an old-fashioned computer that is, unfortunately, password-protected. ...
11
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5answers
802 views

The Word Web of horror - Clue Twenty Two

<<---First clue <---Previous clue As you say the word, the floor starts rising. You are now able to reach the trapdoor. You push it open and climb out. You blink in surprise. You appear to ...
15
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1answer
831 views

Labryca — Floor 1: Now, It Begins

Labrycean Navigator You are currently on: 1F 1F 2F 3F 4F 5F 6F 7F 8F 9F 10F 11F Background "Labryca" is a regular cipher-based puzzle series I plan to run and update roughly every two weeks with a ...
12
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3answers
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Help! I'm dying!

You are woken up to hearing your neighbour shouting - "HELP! HELP! I'M DYING!" You jump to your feet and run out into the street and see a man run away from your neighbours house, but he is too far ...
12
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1answer
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Labryca — Floor 3: Hotshots

All right. No more Mr. Nice Grinadel. Labrycean Navigator You are currently on: 3F 1F 2F 3F 4F 5F 6F 7F 8F 9F 10F 11F Second Floor: Conclusion You had thought Mr. Adams was weird, but Ms. Alperin ...
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A long but relatively easy cipher - Clue Two

<-- Previous clue After submitting your answer in the email, you wait eagerly, on the edge of your seat. After about five minutes, your response comes back. It says: Wonderful. You have ...
14
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2answers
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Labryca — Floor 4: I've Just Seen a Face

Labrycean Navigator You are currently on: 4F 1F 2F 3F 4F 5F 6F 7F 8F 9F 10F 11F A Few Administrative Notes Yes, I’ve come back from the dead… for now, at least. All updates beginning from here ...
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4answers
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The Twenty Doors! (ROOM 2)

This is part of The Twenty Doors series. The previous one is The Twenty Doors! (ROOM 1) The next one is The Twenty Doors! (ROOM 3) ROOM 2: After entering the first door, you find yourself in a ...
9
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3answers
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Labryca — Floor 2: No Cues

Labrycean Navigator You are currently on: 2F 1F 2F 3F 4F 5F 6F 7F 8F 9F 10F 11F Background Here is the second bi-weekly challenge from the "Labryca" series. I wish luck to anyone who is continuing ...
7
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2answers
423 views

Hiker's Cabin Mystery | Pt. III

See Part I | See Part II | See Part IV Finally, you've gained access to his files... but the filenames are all encrypted! Oh, no! You only have one chance to open the files! Which one should you ...
7
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2answers
310 views

Desert Wanderings bring…Ciphers? Part 2

Part 1 can be found here Part 3 can be found here As you utter your answer, along with its reasoning of course, the Sphinx clearly looks disappointed. You are unfortunately… Correct. Clearly I made ...
5
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1answer
355 views

The Twenty Doors (ROOM 8)

This is part of The Twenty Doors series. The previous one is The Twenty Doors (ROOM 7) The next one is The Twenty Doors (ROOM 9) You move on into Room Eight when Kslkgh (a.k.a. Dr. X) finally creates ...
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2answers
709 views

The Great Binary Puzzle - Part 1

You are in a dark room with 1 source of light (a lamp). You see a large door with a combination with nothing but letters. You find a sheet of paper stuck in the door with the numbers, "...
61
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1answer
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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 ...
63
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4answers
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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 ...
57
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5answers
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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 ...
42
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2answers
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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 ...
46
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5answers
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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 don't ...
41
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3answers
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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 quite ...
38
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3answers
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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-...
35
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1answer
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. ...
22
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1answer
2k views

This is an opportunity. Can you take it?

The first thing you hear on awakening is the clock. It sounds just like the one you have in your room. But what you see defies what you hear. You've never seen this room before. You don't remember ...
33
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2answers
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 ...
11
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1answer
755 views

The Three Little Pigs are hiding something

As you work through one of your countless puzzle books, you find a sheet of paper inside with a poem on it. Remembering the last time you found something like that, you decide to take a crack at this ...
11
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3answers
1k views

Christmas Day Cryptogram / Riddle

This is a cryptogram puzzle, with some riddle-style clues to help you solve it. When you find the thing that links all of the clues, that will let you deduce the keys to decipher the cryptogram. Here ...
11
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3answers
562 views

Interesting email I received?

This email recently arrived in my inbox. I don't know how it avoided the spam folder, but it must be important. However, it looks like a dictionary in a blender... you'll see what I mean when you read ...
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2answers
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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 ...
10
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2answers
203 views

A new kind of cipher?

So, I believe that I may have created a new kind of cipher, would you be able to solve it? (I'll let you know what I've decided to name it once you've solved it :) ) ...
8
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2answers
466 views

A not very easy puzzle with an easy answer. Something that a grim puzzler might like

1f411 pirate gibberish 00000010 1f607 . 1f441 1f44f 1f411 . Cigarette ___ lion's-bane@ ワs 22 2 65 61 73 79 160 141 162 164 "2" & right(getMethod("mixintowater"), 5) 9 (4*2) 2 8 _ (...
11
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5answers
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Room 2 of the Maze

Still excited about your quick triumph over Room 1, you head straight for the suspended note and read it: Congratulations on making it through the warm-up to Room 2. From here on out, getting the ...
11
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1answer
445 views

Puzzle Dungeon: The Intro

Inspired by this puzzle that I found by looking randomly at the top-voted puzzles up to page 7. Don't question it. In the magical land of Puzzlandia (I am very creative at making up names), there ...
6
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1answer
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Encoding Morse Code

The letters of a message are converted to Morse code, with a space between each pair of letters and two spaces between each pair of words. Each pair of elements (for example dot-space, dash-dash, and ...
13
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2answers
652 views

Alex, Dave or Jeff

A man has plotted to blow up a building. The police have three suspects. They have received a letter telling the name of the suspect. But it is coded, to avoid one of the other members of the suspect'...
10
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1answer
912 views

The Twenty Doors (ROOM 4)

This is part of The Twenty Doors series. The previous one is The Twenty Doors! (ROOM 3) The next one is The Twenty Doors! (ROOM 5) You now enter room 4. This one has a load of A's and B's carved ...
10
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1answer
596 views

Monoalphabetic Equation

A set of letters has been replaced by $a$, $b$, $c$, and $d$. Following are some of the words that consist of those letters, and their meaning: $abc = a\ title\ (n.)$ $abcd = a\ title\ > ...