Advanced Encryption Standard (AES): Aka, Rijndael, is a block cipher and the only symmetric cipher standardized by NIST (National Institute of Science and Technology).
Block: Data is encoded a 'block' at a time, with one block of data consisting of some number of code words. In CryptCode, the cipher text (encoded) block generally contains more code pieces than the plain text block size. If the plain text code size is k-words and the encoded block size is n=k+2s, then at most s of the encoded words can contain errors and still be decodable.
Block Cipher: A symmetric (both encryption and decryption need identical cryptovariables) cipher which operates over a fixed block size. AES is an example of a block cipher with varying block sizes: 128, 192, 256 bits. Many block ciphers are based of Feistel networks.
Cipher text: Data that has been processed by some encryption (enciphering) algorithm.
Code Piece/Word : A code piece (or code word) in CodeCrypt is a pre-defined size of data, generally (but not limited to) 8, 16, 32 or 64 bits in size. CodeCrypt operates over a field with these words as elements of the field.
Cryptovariable : This is the secret variable which makes traditional symmetric or public key cryptography secure. It is sometimes called 'key' or 'secret key', however the term 'key' is overused and can cause confusion.
Da Yan/Ta Yen: The remainder theorem, or quotient ring product therem, which originated in China (Sun Tzu, a mathematician who lived around the third century CE). Da Yan/Ta Yen in English is 'Great Extension', which is what the first algorithmic form of the theorem was called. The Da Yan is also commonly known as the 'Chinese Remainder Theorem', or CRT. This theorem is the core of the Quotient ring transform, as well as Reed-Solomon codes, cryptographic secret sharing, polynomial interpolation, and many other concepts and applications.
Encoded Text : Data that has been processed by some coding algorithm. While 'coding' often refers to 'error correction codes' -- and refers to CryptCode here, it could also refer to any type of data coding, including compression and cryptography.
Mode of operation: Both block and stream ciphers are used in some type of 'mode of operation'. Modes dictate a feedback mechanism for the cipher. Properly done, this added feedback can improve security and give the cipher text certain properties. For example, cipher text, key stream, or even a counter may be fed back into the cryptosystem. Some modes turn block ciphers can turn block ciphers into stream ciphers or allow for syncronization. CryptCode can be thought of as a mode of operation which integrates error correction into the cipher.
Passphrase: A secret phrase which is used to derive a cryptovariable.
Plain text: Data that is readable or viewable, that has not been encoded/encrypted/CryptCoded.
QRT: The Quotient Ring Transform (QRT) transform is at the core of CryptCode. Two definitions are given below:
(simple definition) Transforms a set of points on a polynomial to another set of points on the same polynomial
(mathematical definition) Transforms an element in a product of distinct quotient ring elements over a given ring to another product of distinct quotient rings over the ring such that the underlying elements in the quotient rings derived from the two products, in reduced form, are identical over the underlying ring.
Stream cipher: A symmetric cipher which encrypts by generating cryptographically random data (i.e., data that satisfies statistical entropy tests and is resistant to cryptographic attack) known as 'key stream', then adding the key stream to plain text. These ciphers are generally much more efficient than their block cipher counter parts.
Rabbit: One the stream ciphers in the EU's stream cipher suite.