Appendix:Glossary of cryptography

This is a glossary of cryptography.

C

 * cipher : A cryptographic system using an algorithm that converts letters or sequences of bits into ciphertext.


 * ciphertext : Encoded text; text that is unreadable.


 * cleartext : The unencrypted form of an encrypted text; plaintext.


 * code : A cryptographic system using a codebook that converts words or phrases into codewords.


 * codebook : A book, table, database, or other object that stores the mapping between plaintext words or phrases and their equivalents in a code.


 * codeword : A string representing an encoded piece of text.


 * cryptanalysis : The science of analyzing and breaking of codes and ciphers.


 * cryptology : The practice of analysing encoded messages, in order to decode them.


 * cryptography : The discipline concerned with communication security (eg, confidentiality of messages, integrity of messages, sender authentication, non-repudiation of messages, and many other related issues), regardless of the used medium such as pencil and paper or computers.

K

 * key : A piece of information (e.g. a passphrase) used to encode or decode a message or messages.


 * keyspace : The notional space that contains all possible keys.

P

 * plain text : Un-encrypted text, text that is readable.


 * private key : The unpublished key in a cryptographic system that uses two keys.


 * public key : The public one of the two keys used in asymmetric cryptography.

S

 * substitution cipher : A method of encryption by which units of plaintext are substituted with ciphertext according to a regular system; the "units" may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. The receiver deciphers the text by performing an inverse substitution.