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| 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! |
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| == Basic Terminology ==
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| * '''Cipher''': a method of encryption
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| * '''Plaintext''': the legible text of a hidden message
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| * '''Ciphertext''': the text after a message is concealed in it
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| * '''Encryption''': The process of turning plaintext into ciphertext
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| * '''Decryption''': The process of converting ciphertext back into plaintext
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| * '''Key''': a string used in the encryption and decryption processes of some ciphers, akin to a password
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| == Basic Ciphers ==
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| === Caesar cipher ===
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| ''Click [http://www.xarg.org/tools/caesar-cipher/ here] to experiment with the Caesar cipher.''
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| The simplest example of a cipher is the Caesar cipher. The rules of the cipher are as follows:
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| Let '''n''' equal a value from 1 to 25
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| Shift each letter in the plaintext forward by '''n''' positions in the alphabet
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| The resultant string is the ciphertext
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| For example, to encrypt the string <code>Game Detectives</code> using the Caesar cipher, using an arbitrary '''n''' value of 2, then:
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| G -> H -> I
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| a -> b -> c
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| m -> n -> o
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| e -> f -> g
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| ...
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| 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)''
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| === Hex cipher ===
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| The Hex cipher, and other variants (such as Octal, Decimal, and Base64), rely on the fact that each ASCII character that you can type has a unique identifying number. For example,
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To learn about cryptography, check out the Game Detectives Academy - a free, interactive series of tutorials!