Questions tagged [encryption]
This challenge is about or related to encoding a plaintext, usually with one or more keys.
20 questions
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Make a Mulenère encryption program
Mulenère cipher is a version of Vigenère ciphers, which uses multiplication instead of addition.
Algorithm
It's simple. First, the password will repeated as much as reach a size bigger than length of ...
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Produce a secure block cipher round function (1 bit round key; 7 bit message) [closed]
We need to produce a block cipher round function with a 1 bit round key size and a 7 bit message size with the highest level of cryptographic security according to our measure of security.
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Encrypting Emojis
Problem
You are tasked with creating a program that performs emoji encryption on a given string of emojis. In this encryption scheme, each emoji is replaced by a unique character (from ...
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Encrypt this Message [duplicate]
Given a permutation of the alphabet and an input string, encrypt the input string by replacing all characters with the one's you've been given.
The capitalization should be kept the same and non-...
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I Rot-13 the source code, you Rot-19 the output!
This is alternate of a rip-off of a rip-off of a rip-off of a rip-off of a rip-off of a rip-off. Go upvote those!
Your task, if you accept it, is to write a program/function that outputs/returns its ...
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Let's Decrypt It!
Note
This is the decryption challenge. The encryption challenge can be found here.
Challenge
The challenge is to decrypt a given string, using the rules as specified below. The string will only ...
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Decode the Dreaded Alphabet Cypher™️
This challenge is inspired by one of my other challenges: Pointlessly make your way down the alphabet
That challenge asked you to take a string of text, and for each letter produce a sequence of ...
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Russian Caesar cipher
The objective
Given a Russian text, encrypt it with Caesar cipher with key 16.
The basic Cyrillic alphabets
The basic Cyrillic alphabets are: (U+0410 – U+042F)
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Let's Encrypt It!
Note
This is the encryption challenge. The decryption challenge can be found here.
Challenge
The challenge is to encrypt a given string, using the rules as specified below. The string will only ...
- 5,350
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Secret Message Part 1, Elements
You and your friend want to send each other secret messages. However, because you are conspiracy theorists and think that the government has a quantum computer that can crack any standard encryption. ...
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Codebreakers and Codewriters
Let's say you have some text, and you want it to send it to your friend, but you don't want anyone else to read it. That probably means you want to encrypt it so that only you and your friend can ...
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Simple encryption for people on a byte budget
Overview
Your goal is to implement RC4 encryption. RC4 encryption, invented by Ron Rivest (of RSA fame), was designed to be secure, yet simple enough to be implemented from memory by military ...
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Decrypt xor-encryption
Your task is to take an encrypted string as input, and output the string decrypted, to reveal its hidden message.
The strings, both the input and output, will contain characters from this list of 64 ...
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Straddling Checkerboard Cipher
The Straddling Checkerboard is a method for converting letters to numbers and was part of a pencil an paper cipher known as VIC
To convert letters to numbers first you have to make a checkboard like ...
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Golfing end-to-end encryption
This challenge carries a bounty of 200 points for the first to answer and remain unbeaten for at least 3 days. Claimed by user3080953.
There's a lot of talk lately about end-to-end encryption, and ...
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Keyboard Encryption [duplicate]
Challenge
Given a string with any characters a-z or A-Z, return an 'encrypted' string, where all characters are replaced by the character next to it (assuming a QWERTY keyboard).
Case (uppercase, ...
user43124
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Implement this key cipher
Implement this key cipher
Goal
Use the algorithm (explained in the Algorithm section) to implement a certain cipher.
The program must read input from STDIN or the closest available equivalent, use the ...
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Encrypting and Decrypting Challenge [closed]
Encrypting Challenge
Your encrypting program must be able to do following things:
Input password
Generate random key
Encrypt random key with set key
Then, the decrypting program must be able to these ...
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Implement the Enigma Machine
The Enigma machine is a fairly complex cipher machine used by the Germans and others to encrypt their messages. It is your job to implement this machine*.
Step 1, Rotation
Our enigma machine has 3 ...
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Find the smallest illegal (probable) prime
An illegal prime is a prime number which encodes information that is illegal to possess - specifically, in one case, a gzip file of the source code of DeCSS, a piece of software to decrypt copy-...
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