Cryptography Basics Terms

I've always had an interest in Cryptography so recently picked up the book "Cryptanalysis: a study of ciphers and their solutions". I figure this is a good place to keep my notes.

Cipher: implies a method or system of secret writing. Cyphers used to to transform plain-text into into a cryptography.
Cryptogram: Single enciphered message.
Encipherment: The process of using a Cipher on plain text to convert to a cryptogram.
Decipherment: The opposite process of encypherment, converting the cryptogram into plain text.
Decrypt: The process of solving a cryptogram without the use or knowledge of the key.

Cipher categories:
1. Concealment Cipher: The secret writing is hidden by a some kind of device.
2. Transposition Cipher: The true letters of the secret message are rearranged in a pattern (key) agreed upon by all parties.
3. Substitution Cipher: Original letters of the plain text are replaced with symbols and the symbols are arranged in the same order as the original letters.

Homophones: When a plaintext term has more than one symbol
Polyphones: symbols that have more than one meaning


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