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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3
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1answer
136 views

Three letters, one dial

You, a great scientist, is being held hostage by aliens. They want to test human intelligence and see if the human race is worth to collaborate with. According to the aliens, if you manage to escape ...
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Encoded Morse Code Interception

A message has been intercepted in Morse code coming from one unidentified station to another, but the radio operators couldn't make any sense of it. Later, another message was intercepted. Here are ...
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Jpe vsm upi ;ry dp,rpmr lmpe yjsy upi str idomh s lrunpstf djogy vo[jrt [on hold]

O,shomr yjsy upi str rcvjsmhomh s )drtord pg_ yrcy ,rddshrd eoyj s [rtdpm ejp od mpy sestr yjsy upi str idomh s do,[;r lrunpstf tohjy djogy rmvpfrt/ Jpe vsm upi jomy yjr,. ejsy upi str fpomh. dp yjsy ...
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Zed's Note: Famously Infamous

My friend Al and I constantly bicker. One time, he proudly boasted that he can crack any cipher ever written, so I put out a little wager: if I can stump him with any cipher I write, he would have to ...
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195 views

What is the hidden passcode?

The passcode is hidden in these sequences of numbers. Can you find what it is?
28
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1answer
387 views

Iceberg Cryptography

See if you can extract the message encrypted in this text box: ...
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207 views

The Weird cipher password?

During your search to the ' great hidden computer virus ' , you realized that you are just a password from accessing it. Frantically , you searched for a clue that might help you . At last you ...
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1answer
158 views

Density type puzzle 2

Here's another puzzle of this type. Perhaps my next one will be complex enough to require the full $72$ x $72$ size. Final answer: (5,2,5)
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107 views

Message for my club members

Two people in particular have come to my Codes and Ciphers Club almost every week. One of them is always expecting a certain message to appear in the weekly puzzles, so of course I can't include it, ...
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567 views

Super Secret Cookbook

You requested the password for a super secret cookbook and received an SMS with the following content: 77733666688833 2555555 777772222337777 2663 777337555222233 84433 6688622337777777 9444844 ...
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Recurring Meeting

The computer scientist's assistant is late at work once again, trying to once again decode their bosses directions for the day. Under meetings, the boss has listed only a single meeting: ...
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2k views

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 ...
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Cryptic Puzzle for Puzzlers: PART II

You are a cryptanalyst who works for the US Army. You have been intercepting what is believed to be enemy spies' communiques. However, the documents are very normal looking: Good Morning, The lasagna ...
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1answer
230 views

Where is the girl?

A girl called Claire suddenly disappeared two weeks ago. She left strange notes before she left. Her parents asked everybody to help find their girl. Last diary entries: [12.02.2019] Prep for mom ...
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232 views

A Cryptic Riddle for Puzzlers

You asked your friend Joe, (whom you know to be avid about cryptography), who he would ask to dance with at Prom and you receive later inside your locker signed by Joe this: Happy as a Lark in a ...
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406 views

An enrypted clue for the police

A well known German drug dealer contacted his accomplice with an encrypted note. The police caught the accomplice during a drug deal and found the note in his backpack. Note: (For those who can't ...
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198 views

Follow me my dear friend

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Questionable Cipher

I have received a rather peculiar cipher and in all my years of crypto, I have never seen a cipher like this. The cipher is Numeric, Uppercase mixed with Lowercase. The only hint I'm given is "Capital ...
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Cipher: First time

So, this is my first puzzle here and it is a cipher. But it starts with an instructional poem: The cipher below Shouldn't forebode It is but a version Of a known code Start at a place ...
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187 views

%#@& : $!*^ :: SOFT : 5697 :: 8924 :?

If %#@& is coded as $!*^ and SOFT is coded as 5697. ...
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473 views

What is lost can never be saved

Donnie and Violet are Ivy-League college students, and don't have fancy names or costumes or anything. But they do have superpowers and are attempting to track down and stop whoever is trying to ...
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1answer
200 views

Welcoming Cipher Puzzle

Please leave this puzzle for users with less than 200 rep. Each of the following lines until the last provides a significant clue for solving the next cipher. Letters have a natural order C SEA WRA ...
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1answer
281 views

Hiker's Cabin Mystery | Pt. XVI

It's been a whiiiiiile since we've had one of these! You continue on through the forest and enter the labyrinth, once more. And again, you find a small piece of paper: ...
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1answer
239 views

How to solve this cipher?

I'm given the cipher ESELUBRKXDBWTHARE and am told that it's a J. Bond quote. The only cryptography techniques I know are caesar ciphers and substitution ciphers. I learnt the vignere cipher after ...
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1answer
433 views

Flying pigs arrive

You’ve built pens for flying pigs. Being, well, flying pigs, they pick their own accommodation in full accordance to their preferences. Can you figure out what creature joined them? Pigs only occupy ...
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All Aboard the Factorio Train to Far Harad

It’s been a while since you started up your Factorio game and you are trying to remember what you had done with your four trains. Use the clues below to work out which deposit each train is collecting ...
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1answer
77 views

Missing number in a 5x5 table

I'm trying to find a solution for the following puzzle. A friend sent it to me and I know that he didn't create it and that's about it for the original source; I tried to find it on the net but I ...
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107 views

Phonetic Substitution Cipher

This cipher uses a unique phonetic alphabet. Consonant sounds (not necessarily in the text): m b p f v r l d t s z y n j ch sh zh* w ng g k thin** this** h *Zh refers to the s in conclusion or the ...
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Solve this simple Zipper Cipher

This is a very simple variation on a very simple cipher. I'm sure one of you geniuses on this site will be able to figure it out without any hints (aside from the title). I encourage you to use a ...
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138 views

How do I answer this?

So, I'm trying to figure out this weird code that was sent from one of my friends. Could someone please tell me the sentence within? 30 30 31 31 30 30 30 30 20 30 30 31 31 30 31 30 31 20 30 30 31 31 ...
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101 views

An Autokey Cipher (Now with Added PHP Code)

15.26.32.25.23.25.19.11.5.20.3.3.6.12.0.23.4.8.8.8.25.4.43.32.0.3.7.4.3.11.10.18.35.7.4.8.5.21.1.5.58.13.38.3.2.1.62.2.55.10.4.36.14.2.1.3.9.71.59.2.24.13.79.73.14.10.12.3.3.8.65.77.40.75.7.7.74.42.3....
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218 views

Room 213: Because of the Reindeer

Credit: Brandon X. This is part of a larger riddle room puzzle. Other rooms: Room 11 Once you enter the door labeled “3”, the door immediately shuts behind you. You are immediately in a room of ...
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469 views

A puzzling nature walk

While wandering through the forest Taking lots of snaps I found a mossy clearing Where my pup could take a nap I glanced around the bushes I heard a rustling sound And there I spied a crumpled note ...
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Peterhead Codes and Ciphers Club: Weekly Challenge II

This is another cipher-based challenge I created for my club. The story you uncover is generated from Crusader Kings II. The events of this challenge precede those of the Reverse Engineering challenge....
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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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code the following word using the sample code logic

Sample apple = btqreqemf mango = ntbreoehp banana = ctbreoebob code: orange = ?
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Know your primes

Did you know that a prime, regardless of its base, is always a prime? I am looking for a prime. It’s the largest of its kind. In solving this puzzle, the answer you may find. ...
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626 views

A journey through letters and numbers

In the year 2407476658354979366708415043923125501315337890943021769230219230892355006879909214795402102204224, as cosmopolitanism is in the air and companies are more than ever bound to ...
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258 views

Peterhead Codes and Ciphers Club: Weekly Challenge

This is one of the cipher-based challenges I have created for my club. This is a lengthy puzzle so feel free to post partial answers. My golden rule is that moving something that isn't glued down ...
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454 views

100 Years of GCHQ - A quick afternoon puzzle!

I'm off to the Science Museum London tomorrow, to the Exhibition celebrating 100 years of GCHQ. As such, they sent me a little reminder email this afternoon. On the bottom of the email was the ...
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148 views

Any help with this code (source text based game)

Source: Torn.com (text based rpg game) 31 30 35 20 31 32 31 20 31 30 31 20 36 38 20 37 30 20 37 31 20 35 34 20 31 31 39 20 31 31 34 20 37 34 20 37 35 20 36 35 20 31 32 32 20 31 30 36 20 35 33 20 31 ...
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The Hidden Treasures

Credit: Brandon X. My friend made this riddle and I think it’s pretty well made with lots of components, so here it is: ...
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What does this message in paper say? [closed]

You wake up in an old horse wagon and get a piece of paper with strange symbols. What does it say? //Anyone can help me. Please!
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A trip to the library

I try to go to the library at least once every month, so I've developed a pretty good relationship with the librarian, a nice old man who sometimes teases me about my broad set of interests. Yesterday,...
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1answer
935 views

What a beautiful canyon!

My friend sent me an image of this beautiful canyon and asked me to work out where he is. More specifically, his latitude and longitude. The only issue is that he's in Europe and this photo is of the ...
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618 views

What's the correct password?

A detective was working undercover to try to bust a suspected gang of criminals. He got invited to a fancy club that needs a password to get in, but the gang leader said that everyone will be given ...
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1answer
348 views

Oh go dear! again… we Here

What is the missing one? $\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, $ [Some colours look alike, sorry about that, but then again you don't really need to be able to make a visual difference between them, ...
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1answer
527 views

Secret message 01

116313333134261542156511321455121126113213151461123615112516114142 OK, so recently I made up a way of sending coded messages and I was just wondering how difficult it would be for someone to crack. ...
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180 views

I wrote you a message

Take the dogs out for Millan, but only after you find the alphas. dog 1234 Ny nx dog 556 fqrtxy Fzlzxy 567 dog 5819 gzy 2 nx 345 dog 13445 fqwjfid 74859 mty. 55645788 dog 1234 ...
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The Grand Grid II

Have a look at the first Grand Grid to get an idea of the basic concept Each Grand Grid involves you discovering clues that allow you to solve a logic grid puzzle. The second in this series will be ...