Difference between revisions of "Cryptography"

From Game Detectives Wiki
Jump to: navigation, search
[unchecked revision][checked revision]
m (Caesar cipher)
 
(16 intermediate revisions by 2 users not shown)
Line 1: Line 1:
Cryptography is the process of hiding messages; either by concealing them (eg. hiding them in an image), or by obfuscating them outright (eg. substitution cipher).
+
To learn about cryptography, check out the [http://gamedetectives.net/academy Game Detectives Academy] - a free, interactive series of tutorials!
 
 
== Basic Terminology ==
 
 
 
* '''Cipher''': a method of encryption
 
* '''Plaintext''': the legible text of a hidden message
 
* '''Ciphertext''': the text after a message is concealed in it
 
* '''Encryption''': The process of turning plaintext into ciphertext
 
* '''Decryption''': The process of converting ciphertext back into plaintext
 
* '''Key''': a string used by the cipher that is neither the plaintext nor the ciphertext
 
 
 
== Basic Ciphers ==
 
 
 
=== Caesar cipher ===
 
 
 
The simplest example of a cipher is the Caesar cipher. The rules of the cipher are as follows:
 
 
 
Let '''n''' equal a value from 1 to 25
 
Shift each letter in the plaintext forward by '''n''' positions in the alphabet
 
The resultant string is the ciphertext
 
 
 
For example, to encrypt the string <code>Game Detectives</code> using the Caesar cipher, using an arbitrary '''n''' value of 2, then:
 
 
 
G -> H -> I
 
a -> b -> c
 
m -> n -> o
 
e -> f -> g
 
...
 
 
 
and the resultant ciphertext would be <code>Icog Fgvgevkxgu</code>.  To decrypt this string back into <code>Game Detectives</code>, the process can simply be reversed by shifting each letter of the ciphertext 2 places backwards.  (''Note: another common name for the Caesar cipher is ROT<n> - ROT13 indicates that each letter is shifted halfway through the alphabet)''
 

Latest revision as of 14:37, 24 May 2018

To learn about cryptography, check out the Game Detectives Academy - a free, interactive series of tutorials!