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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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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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Hiker's Cabin Mystery | Pt. VIII

Part VII is still up for grabs! At last! You've solved the mystery of the cards! Now that you've gotten into the hiker's computer in the hotel room, it's time to explore! Good news! There is only ...
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How to approach finding a cipher algorithm when you have the code and the decoded text

I have a text that have been encoded into a grid of black and white pixels. I have both the grid and the decoded text, but I don't know how the text have been encoded. What's the best approach to ...
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Pentagon chipher

Please help! Its a swedish scoutcipher.
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Beginner CryptoGram - Msgs From Your Puzzle Community

I like simple ciphers. Here is one, no tricks, alpha-numeric substitutions only:
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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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Hiker's Cabin Mystery | Pt. VI

The only part that doesn't have an answer yet is Part II! Chop, chop! You finally are able to get out of the airport after quickly solving the mystery. You are becoming quite the detective! Only... ...
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Find the cipher used

Each of the following lines were said by various famous personalities. Each line corresponds to one person. There is no relation between these lines. After obtaining the names of these people, A 6 ...
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Hiker's Cabin Mystery | Pt. III

See Part I | See Part II < needs answer!! 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 ...
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The “Jumbled” Cipher

The elusive "Jumbled" cipher has stumped scientists and cryptographers alike... Not really, but it will stump you soon... The Jumbled Cipher is a mysterious text cipher that puts text into an ...
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Mutineer's Treasure

Background: Your team has recovered a sunken ship. In the hold there is a small room that appears it was intended as a smuggler's room. In the smuggler's hold are three decayed corpses a bunch of ...
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Is it a word? Really?

Grandpa says: show that the following number equals a 5 letter word with multiple meanings (one of them not good) I I I X I I X I I X I I I X I I X I I I was wondering if that silly thing ...
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This is my cipher

Solve the following: Ujlw oz vi ovdwui, Ncep hs ob xuuo, T'yz miamy hfid ujlw, Htu etr sqp eiic. Hint: Hint 2: Hint 2a: Hint 2b: Hint 2c: Hint 2d:
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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. ...
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The Librarian's Labyrinth - Part III

"This Library is HUGE!," You say aloud. You hear your voice echoing through the halls and nothing else. How could this be? Who comes here? You start examining the books on the shelves. It's just your ...
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Just a Simple Number Crossword

I made a small number crossword for my mathletes club that I thought I'd share. It's not too hard, I think it's just right for a coffee break. Have fun! (Edit: No answer has a leading zero)
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History Calls - Twice!

You'd send a letter to me, but I'm not quite what you think. You'd send a letter in me, but only if you didn't know me. I was a gem in my day for being both bold and precise. I stood ...
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A letter with no particular backstory

So, I was walking down the street when this paper materialized just in front of me, as if from thin air. I'm not sure if I can decipher it, maybe you can? It also smelled like fish a bit.
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A fun series of riddles!

All of the clues will lead up to the key for a Vigenere Cypher: eutnn wo vvsf. Clue 1 (from www.riddles.com) I'm by nature solitary, scarred by spear and wounded by sword, weary of battle. I ...
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Riddles and ciphers / All good ways to flex the mind / Can you solve my task?

I have arrived new / Here with ciphers for your eyes. / Can you solve this task? ...
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Cyrus' Adventure (Part 7)

The wall opened. Cyrus and T.E.D. got out of the room. Suddenly, the passageway started collapsing! Cyrus was terrified. T.E.D. grabbed Cyrus and quickly rolled out of the passageway. They got into ...
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Geography at the pixel level

(enlarged version) The answer is a group of islands.
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Can you solve this? Cipher I found

Here is the cipher you need to solve, it is an actual English text: ...
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Find the result of this dual key cipher

I came up with a neat little cipher that I'm calling the dual key cipher. The basic premise is that there are two cipher keys that, when used together can decode the cipher text against a given ...
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Find My Mission For Me

I am a spy for the CIA. Since I am in a hostile territory, my next mission was given to me in a very coded manner. Today, while playing chess in the local park a briefcase landed on my head. Feeling ...
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What words Atbash plus Caesar cipher to other words? [closed]

If you Atbash cipher plus Caesar cipher after, you get a new set of ciphers, and I tried 4-letter words for Atbash plus Caesar shift 1 and I got: cams <-> yaoi ghat <-> Utah haji <-> tars ...
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An Aklahp Mystery

You are a detective in the city of Aklahp, which has had some problems with crime in the past. It used to be just simple burglary or breaking an entering, but things have been getting worse recently. ...
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Detention in 1997

As summer break is coming up, you have started to misbehave in school, getting sent to detention quite often. On June 20th, something interesting happened, and made detention a little more fun. You ...
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How to decipher

I received the following challenge as a homework problem. Not much info is provided with it, except for the word Decrypt! at the end. This problem is online on a password protected school site. So I ...
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Cyrus' Adventure (Part 6)

The robot's program started running. It twisted its head, torso, arms and legs. After a few minutes, it stopped twisting and vocalized a few sentences, "Hello master. I am T.E.D. and I am here to ...
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Unknown Cipher? [closed]

gX18gICAgIF9fXyAgX18gICAgICBfXyAgIF9fICAgX18gICAgICAgICAgICAgICAgICAgICBfX18gICBfXyAgIF9fICANCi8gX2AgLyAgXCAgICAgfCAgLyAgXCAgICB8ICBcIC8gIFwgfF9fKSAgL1wgICB8XC98IHwgfFwgfCB8X18gICB8X18pIC8gX2AgDQpcX18+...
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Coordinated efforts

I was showing off my knowledge of obscure geography trivia to my father. He admitted he'd never remember all those details, but insisted that there was a certain other topic where nobody could ever ...
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Invade the Pyramid if you Dare

Before you lies a pyramid, with a giant statue blocking the entrance. ...
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A strange message full of dice came in my mail

So I got a package today that contained the strangest contents. It was a set of dice, each of them numbered in one of the corners. Arranged, this is what numbers or characters displayed on each dice, ...
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How to decrypt simple binary code to alphabet

Part of an alphabet is given by the code: This code is used by Fred to send a message home to his mum. She receives the following signal which includes a parity check digit on each word. ...
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Part of a challenge, from a group of adults, who break ciphers

I am part of a group of adults, a cipher club who like to decode random ciphers, from texts to symbols and other things. We were presented with a set of 5 ciphered text, and we have managed to crack 3 ...
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What in this world is she trying to say?

I happened to meet one of my friends after about a couple of years. Obviously we both were very happy, but still, she didn't leave her habit of challenging me to decipher what she was saying. I ...
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Where are they being held?

In my dream, some People asked me for help. They said I should wake up. So I woke up and there was this letter. Dear Percy We got caught and only you can help us. You've 60 minutes (try it ...
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The garden where everything is possible

An old man spoke to me today. He said: "A long time ago, I buried something very important. That was 20 years ago." After he said that, he gave me a note where it was written "Hyih Jbimjbilom ...
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The programmer who loves dogs and puzzles

Your programmer friend, Daniel, went on a two week long vacation, and asked you to look after his adorable dog. He loves dogs, and he certainly doesn’t want a stranger to do this job, so you agree. ...
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Eight Sisters Treasure Hunt

Eight sisters don't guard the essential hoof This is from the game CreasureQuest, so I suspect the solution in context with the historical background (the lost treasure of the Flor de la Mar, Afonso ...
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Jealous, Lying, or unAmerican

I opened my email today to find this odd image. I suddenly had a strange craving, which fortunately I was able to satisfy outside my local Starbucks—-I happened to be driving by literally as the ...
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I'm drawing a blank on my name, help me out?

I'm a wrestler, I know that because I just got hit over the head harder than I've ever been hit before. So hard, in fact, that while I'm trying to remember my name... all that comes up in my head is: ...
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Someone scrambled my calling sign- who am I?

Before I left the scene of the crime I left my calling sign... But on the news the next morning all that was left was the following: .Iaaabmmnt Which seems to ...
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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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Silly Sally's Movie

My friend Sally and I love watching movies on Friday nights. This week it's her turn to pick a movie. Sally: "I won't tell you the name of the movie but I will say this: I love eating peanut ...
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Unlocking the dungeon door

Any feedback is welcome. I'm new to puzzling in general so please let me know how long it took you to come up with your answer and what your thoughts were. I have tough skin. Hint Hint 2
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Bro's password… must've forgotten

My overseas friend has forgotten the password to his SackExpunge account, and the only information he wrote down about it was this: Username: LiveSound Password: ...
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Help deciphering number cipher

21,14,01:15,03,01:19,11,10,10:02,15,18,01:21,15:05,01,13,03,11,21,01:21,14,15,21,01:19,14,15,21:21,15,19,21:19,01,05,01:09,05,15,08,01,03:09,03:04,01,07,21,14,21:21,21,11,03,20 9,10,13,1 we ...