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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11
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2answers
944 views

Batman and the grid

This a sequel to: Batman and the piano Master Bruce has received three items, in the mail, from none other than Edward Nigma. One item is a piece of paper with a grid of dots in an arrangement of ...
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Can you crack the Magic Diary's encrypted message?

Can you help find the hidden message in this encrypted text? A young Science student / Stack-Exchange enthusiast stumbles upon a magical encrypted diary of a fellow he has always admired. He finds ...
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Master Bomb Defusers

Day 115 of your investigation and you and your ever-faithful-if-only-a-bit-slow partner have finally caught the trail of your arch-nemesis, a serial bomber known only as "Mr. 5". Doing your best to ...
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615 views

(According to me.)

Can you identify the six things below and determine the final answer? First thing My first three are the code for a port airport in Malaysia. Next you'll need one of the least-common ...
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2k views

Decode the message enciphered in these symbols: ↗↑↙↓↘←↑↙↘↘↗↓↗←↙↓↖

↗↑↙↓↘←↑↙↘↘↗↓↗←↙↓↖ The first character of the plaintext is 'P'. The final character of the plaintext is 'E'. Hint 1; Hint 2: Details (not part of the puzzle): "↗↑↙↓↘←↑↙↘↘↗↓↗←↙↓↖" is the cyphertext....
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How will you save Mike?

A direct hint: this question. Question starts from here: You are Dr. Nathaniel - a renowned archaeologist, and involved in a research about an ancient site. But, there is only one problem - the ...
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1answer
359 views

The mysterious email reply

(Previous part here) Having worked out the threat in the previous email I chose to take whoever 'they' are's rage. I deleted the email and decided to write a reply... Ok, I think its about time you ...
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The Temple of Puzzling

Part of the Community Metapuzzle, although it can be solved on it's own. The password in the puzzle below is also the word needed for the Metapuzzle. Link to the metapuzzle by Deusovi is here. ...
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Can you decipher the hidden message in this Christmas card image?

Sent by a friend in Germany. I have no idea what it says yet!...
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End of the Maze

This the final installment of the Maze series. Here is Room 1 and here is the previous room. After you enter the answer from Room 5, you wait for the door to de materialize as usual, but nothing ...
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V for Vendetta - Who am I?

This link here shows how many "Who am I?" riddles we already have on this site. Obviously, there are many of them and they're mostly riddles describing an object in some funny way. On checking the ...
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Preparing for the end of term performance

It's the first full week of term at Farthingbottom School and Portia, Felix, Primula and Randolph have arrived in the music room for their lesson. Professor N. Igma is nowhere to be seen, but he has ...
19
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1answer
987 views

Oh God! help me

I have just fluffed my exam. See, Grades don't matter to me but it apparently does to my parents and the head teacher who has asked me to write a letter explaining the reasons of my disastrous results....
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Linguistics: Japanese Squares

These are the squares from 1 to 100 in Japanese kanji: 百、六十四、十六、九、八十一、三十六、四、一、二十五、四十九 Which is which? If you already know Japanese/Chinese numbers, then sorry, this puzzle is not for you. Needless ...
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My new little friend

A few days ago a new little friend became part of our family. I asked him to introduce himself and he left this message for you: Who is my new friend??
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Finding Detective Jack!

I am Aidan and I am a detective. I am in a country I have never visited before. Jack and I have been working on a task for a few days now. We have been very successful in solving a murder mystery ...
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471 views

Oh boi! Dis waas never Engliz! #2

This puzzle is second in the series, the first one being this. But these are related in no way. Below are some weird combinations of letters, which are actually words translated in some different ...
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4answers
774 views

He forgot his own password

Avid puzzling stackexchange lurker Mr. Mnemonic (first name NOT Johnny, I promise) is having trouble remembering his login credentials. Knowing that he can be incredibly forgetful, he created a ...
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The mystery of the anonymous email

It is a bright Sunday afternoon. You are on a holiday, enjoying your cappuccino. Suddenly, you get a call from your boss at NSA. He tells you that a psycho-hacker has sent him and the whole staff a ...
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The impossible door!

You are standing at the door to a lost temple in Georgia (the former Soviet Republic). You are an expert in lock picking, but there is no keyhole. You then realise that there is a word that will open ...
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Translate into a sentence

111 221 241 151 222 543 421 233 161 166 222 331 353 444 The problem is to translate this into a sentence. CLUES: 111, could also be ...
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1answer
596 views

The Cipher Machine

"CIPHER, CIPHER, CIPHERS. I LOVE CIPHERS. A LOT. YOU HAVE NO IDEA HOW MUCH I LIKE THEM. THEY ARE VERY FUN!", said the cryptographer. "YOU HAVE NO IDEA." "ANYWAYS, THERE ARE INPUTS AND ...
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A Magical Cryptography Puzzle

The following is the first and second sentences of one of my favorite (and fairly popular) fantasy books encoded in a cipher I created a few years ago. I'm quite certain it's breakable, but hints/more ...
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Is there a secret message in the first decimals of PI?

Is there a secret message encoded in the first decimals of $\pi$? Source: Vi Hart
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An encoded message for Nigel

Nigel came inside from his back garden carrying the peas he'd harvested, and dumped them onto the table to be sorted according to which were edible and which weren't. Just as he did so, he noticed a ...
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Crypto-wordsearch-gram: “You Are a Member of the Rebel Alliance, and a Traitor!”. A cryptogram hidden within a wordsearch

You are a member of the Rebel Alliance. You have been captured by the Empire and imprisoned. In a stroke of sadistic brilliance, your guards have denied you all reading matter except "Uncle Vader's ...
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1answer
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Sweet! Dream! Another hyper-modern art piece

This puzzle belongs to the puzzle series: hyper-modern art After cracking the door code of the last room, the two friends in the gallery of hyper-modern art are moving on to the next room. "Oh, look ...
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There's been a kidnapping!

Alfred C. Bacon, an avid puzzler, has been kidnapped! Fortunately, we were able to find where he was being held. Unfortunately, he was no longer there. Fortunately, he left us a note, letting us know ...
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1answer
589 views

A Timey Wimey “Sci-pher”

It's time to pull out your favorite Sonic-Screwdriver/Lightsaber/Wizard's Staff and hop into your Police-Box/Delorean/Phone-Booth, because this puzzle is going to require geeky knowledge and accurate ...
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Yet there is method in this Morse code

Sometimes a nonsense telegram makes much more sense after a methodical maneuver. Here’s one for fun: - . -.. / ... .... . . - ... / ... . -. - / .... .. ... / .- -. - / - --- / ...
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1answer
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I went on a world tour and came back home

After you enter the right password, once again the door opens before you. You are not surprised to see another door blocking your path; looks like they want a three letter password this time. However, ...
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1answer
452 views

My new cipher with numbers

I have thought up one simple cipher. Hope it didn't exist before. Try to crack it! Here is encoded one sentence in English consisting of three words. $(2_ 2,5_ 2,7_ 5,8_ 5,9_ 4,14_ 4),(6_ 2,7_ 1),(...
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A married couple

Disclaimer: This puzzle is from a university in Israel, computer science. Its in a real document written in Hebrew so no point in posting it. There is no link to it on the internet. There is a couple ...
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734 views

The Mysterious Disappearance of Doctor F. Andrews [Part 1]

This is my first real puzzle, so I hope you enjoy it! Sorry if the writing is a little poor, etc.. You are the unstoppable Detective Joshua Brown, and no puzzle can stand in your way! The Case: ...
11
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1answer
424 views

220 black squares (but that's not the point)

Some hints for this question have been embedded in this challenge: Counter-Red Spiders. ...though that is a standalone puzzle. The title technically describes this puzzle. There are, after all, four ...
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1answer
914 views

Lights in the Dungeon: Hooty and the Message

This is the fifth in a series Lights in the Dungeon puzzles. previous (4th) <-- There is a lot of flavorful fluff here but, if you want, you can probably just skip down to the map and try to ...
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465 views

A strange poster

Can you solve the cipher on this poster? (click for better quality) Hint 1 Hint 2 Hint 3 Hint 4 Hint 5
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1answer
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Counter-Red Spiders

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Title based on this xkcd.This puzzle contains hints for 220 black squares (but that's not the point) but is a standalone puzzle. ...
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Justice and Fairness: Part 1 [closed]

A friend of yours was part of a secret society and was put on trial on 15 December 2014 without a lawyer. Alice encrypted the trial's transcript and sent it to Bob, but double agent Carol was able to ...
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855 views

Don't clear your terminal history 2

Previously, on terminal use... The door accepted your input and slid open! Unfortunately, so did a trap door under your feet. You slide down and end up in another room. The only apparent exit is a ...
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1answer
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The Cursed Breakfast

So yesterday on the bus ride back from school I was sitting beside my friend James talking about food (we were really hungry from all the still life paintings in Art class). Suddenly, his gaze ...
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853 views

Which door leads to freedom?

You wake up in a room. In front of you, there is some paper: It's the day, not the year or the month! It's very useful to abecedarians. 639407344. But never forget the time, for its another key.Jsz ...
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767 views

How do you decrypt a keyword transposition cipher without keyword?

I have computed the keyword length using I.C. but I don't know how to derive the first keyword. This polyalphabetic cryptogram requires two keywords to break, but I am not sure how to get either of ...
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Reverse Engineer These Five Ciphers

This is the latest material I have made for my Codes and Ciphers club. It involves showing both the ciphertext and the plaintext for messages using each of five ciphers alongside another ciphertext ...
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The Twenty Doors (ROOM 10)

This is part of The Twenty Doors series. The previous one is The Twenty Doors (ROOM 9) There is some paper taped to the door in Room 10: Well done! You are now halfway! To mark this event, this ...
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385 views

What is JonMarkPerry trying to tell us?

Following in the footsteps of MOehm, leoll2 and the formerly known Lukas Rotter (who has deleted his account D:), we have a new name to add: JonMarkPerry! In his profile we find an interesting image: ...
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Find the celestial body

Last week, a group of 5 astronauts went on a space-tour. They accidentally got crashed on a celestial body in space. Luckily no one was harmed! They were amazed to see some highly intelligent aliens ...
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Pixel Cipher Puzzle

You are given the following plaintext/ciphertext pairs: they_got_my_contract_back_to_find_ to_their_alarm_a_dog_had_signed_ sonic_boom_sonic_boom_sonic_boom_ ...
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Six Series, Six Words

Update: I've just realized the image had a major flaw in it. I've added a new image and made sure it's correct. Nothing else has changed, only the image. Sorry for the inconvenience. I have six ...
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876 views

Half an awful haiku

Attempt to find the last word: Cheryl nowhere errs She ebbs one or nag envy Aha flap green gel Purely abjurer reef Fur roof bar be ant rail Nun sync terra ???