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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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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 ...
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Binary cryptogram from a friend

My friend sent me a "puzzle" in binary, and said that there are multiple steps to solving the puzzle, all of them including decryption. I translated the binary into text and he said that was a good ...
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Riddle Number Four

Time for a more challenging encryption, seeing how riddle #3 was decrypted so easily. First, I must note that this encryption was inspired during a chess match I partook in. I call it the ENIGMA ...
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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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What is this e mail really saying

Veteran investigator Ken Smith had been following a suspicious e mail trail between John Jones and Robert Brooks.This particular one caught his attention. He was trying to figure it out. From: Jjones@...
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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 ...
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BFTIODFTTWKBCSC

This is my first self-developed cryptographic puzzle. I hope it is neither too hard nor too easy for you to break, and that you enjoy it. Please do not only post the answer, but also your way towards ...
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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 /...
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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: ...
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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....
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Crack the pigeon code

Can you crack this message? It was discovered in a chimney in 2012 attached to a carrier pigeon and was most likely sent during the D-day invasions. The GCHQ was not able to crack it, even after ...
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Grandma's keynote

Found this note which is addressed To my grandma, in her chest Since she's passed now, here's my quest.. What tickled her interest? And who invited her as guest?
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Finding Rogue Kitty II

Having been met by a group of very unhappy bosses at Kitty is being 'returned' to the staff car when suddenly there is a commotion and she makes a run for it. As they chase her, little old ladies ...
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Encoded Dreams Cipher

This note was found at the scene of a Parisian artists loft in the 1960's. Sadly, he committed suicide the day before his first major exhibition. Can anyone decrypt his final written words? (It is ...
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I don't think I overcomplicated this

To: Bob <bbob@bobinator.com> From: John <jjohn@johninator.com> Title: I don't think I overcomplicated this Hey! I made a "challenge" for my kids. Do you think it's alright for them?...
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Coloured dot cipher

I, as a curious being, stumbled upon a page which had a hidden dot cipher in it. Part of the console states: [...] we left you a little message in the dots of the footer (Source: segment.com) The ...
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The Congratulating Cryptogram

A sequel to "The Kind Cryptogram". This one is actually pretty hard, so I can give hints upon requests. (thanks to puzzledPig for the suggestion!) There are 4 "layers" to solve. In your ...
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Need help with a cipher

I am trying to figure out a cipher I think I found in a book from 1982 and it's a 36 year old mystery we are trying to solve (I will reveal the book if this turns out to be something so everyone can ...
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Can anyone decipher this?

My friend just sent me this 5627 4654554 With a keyword of 'Digital' Which is apparently going to make this have some sense: At first, it's difficult to understand. But once you read down, you ...
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Crypto Riddle for a bonus track

here is a crypto riddle a artist named Master Boot Record put on the page of his music. 087 104 101 110 032 116 104 101 032 077 111 111 110 032 119 105 108 108 032 115 104 101 100 032 110 111 032 108 ...
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The search for dracula - a puzzle

Me and some friends are playing a roleplay about Dracula in the modern age. Last night, we received the following puzzle from the game-master. (7 1 1 1 1) (17 8 8 8 8) (4313 2755) With the ...
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Cipher my friend sent me

"The world is: ::: :#: : ::## :### / :##: ##: #:::" My friend sent me it and said the use of the symbols : and # don't matter. It's the pattern that matters. The hints he sent were: (EDIT) I worked ...
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How to solve this puzzle?

I have solved the sudoku. Scratching my head on the second part. Any hints? It is not picked from any competition. One of my office colleagues usually post these types of puzzles on emails for fun ...
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Encrypted message (unknown algorithm or plaintext)

I've been redirected here for more, or rather more accurate help from the crypto section of stackexchange. Long story short, we have this assignment that is bugging me. We are supposed to be ...
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Binary puzzle in World of Warcraft

I apologize if this isn't appropriate here, but it's been driving me insane. Essentially, a puzzle was recently introduced in the video game World of Warcraft, which no one has been able to solve. ...
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A deciphering riddle

Recently in class a computer science related deciphering riddle was shown which I could not solve. For the course itself it is not obligatory to solve it but I am interested in the topic and I wonder ...
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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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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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Definitely not suspicious

This unsuspicious ... post - has just a bunch of random letters. No secret words, no silly ciphers, nothing. Nothing to see here. Goodbye. Urgent secret message: Go to another question ahem, what ...
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Solitaire cipher riddle

I am trying to solve this problem but with no clue of what it actually means. Only thing i know is that it is solitaire cipher hidden message/key. Here is the content of the image: To: root@...
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Cipher Puzzle posed to me by my friend

My friend recently sent me some puzzle, and it has me stumped. I'm not that good (garbage, actually) at cipher puzzles, so was hoping if anyone could help me out with it. It is.. "General O has ...
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Stuck trying to figure out a hidden message

As part of an ongoing "treasure hunt" in an online game that I take part in, there have been several forum posts made in an attempt to hint the participants to finding certain locations. However, ...
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Decoding ciphertext with base64 yields obscure unicode

Context: I was given a piece of encrypted string to decipher and I have been stuck at it for a while. To not ruin the point of the problem, I will provide only some description of the text and my ...
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What's this message? It should be in italian

I received a challenge, deciphering "cgo feco a atm", the result, if a sentence, should be in Italian. I've tried the ceasar cipher without success, maybe you can help? Thanks!
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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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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 ...
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Solve it… Uncover the mystery!

One of my friend, who is really too good with cyphers and puzzles challenged me to solve this one. I think it reveals a name, or date or some information with which he can surprise his friends. That's ...
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Trying to de-code this and I'm having a lot of trouble

The code is: dsetg nvxgn abfus fcaur vvkyq llszs yybik pkefa vbyjj stalk aupoc dvyai qnlrj iewzb qfcct mgqrg xxuqy sapeb reahl btxbz wisfd klbqr letxa zhu I've run it through a bunch of ciphers ...
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What Encoding Algorithm is this? Encode table included

Take the word "puzzle" for example. What this algorithm will do is first break it into pairs: pu zz le Translated using the encoding table: ...
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Riddle is boggling my mind

I really need help with this. Any ideas? I think it has something to do with 1D arrays, as per the hint at the bottom. 64x10 implies that there is some sort of table? ...
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AWS Quest - First Clue

AWS are hosting a puzzle hunt: https://aws.amazon.com/awsquest/ - the first clue is here: https://twitter.com/jeffbarr/status/972382654682120192 The only thing we have to Amazon Sphere is Sphere ...
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I was solving a story where there is a puzzle of the following

I was solving a story where there is a puzzle of the following... Can anyone help? There was the picture of Rod of Asclepius beside the alphabets, if this is any sort of clue. What can fit inside ...