Nofish - A new stream cipher

The purpose of this paper is to provide a description of the Nofish cryptographic algorithm. This paper is intended to release the algorithm to the cryptographic community, for its future analysis and possible use. The name of the algorithm comes in respect to other well-known secure crypto algorithms like Blowfish and Twofish and since this one has not gained this status, I call it Nofish. 1. Algorithm description The proposed algorithm is a synchronous stream cipher, more precisely a binary additive stream cipher because it using the XOR function to encrypt the plaintext. The design is based on HENKOS stream cipher (http://eprint.iacr.org/ 2004/080.pdf), the functions used in the internal state are kept, the initialization and mixing key part being modified with respect to its revealed weaknesses. This stream cipher uses a named key of 64 bytes (512 bits) as a secret key and no initialization vector. Figure 1. Structure of the Nofish stream cipher m i mixing the key m_key kkey kkey_rounds g Si Si+1