Loiss: A Byte-Oriented Stream Cipher
This paper presents a byte-oriented stream cipher - Loiss, which takes a 128-bit initial key and a 128-bit initial vector as inputs, and outputs a key stream of bytes. The algorithm is based on a linear feedback shift register, and uses a structure called BOMM in the filter generator, which has good property on resisting against algebraic attacks, linear distinguishing attacks and fast correlation attacks. In order for BOMM to be balanced, the S-boxes in BOMM must be orthomorphic permutations. To further improve the capability in resisting against those attacks, the S-boxes in BOMM must also possess some good cryptographic properties, for example, high algebraic immunity, high nonlinearity, and so on.