HC-256 is a software-efficient stream cipher. It generates keystream from a 256-bit secret key and a 256-bit initialization vector. The encryption speed of the C implementation of HC-256 is about 1.9 bits per clock cycle (4.2 cycles/byte) on the Intel Pentium 4 processor.

The purpose of this paper is to recommend to cryptographic community and information security specialists, for analysis and testing, a new cryptosystem based on a synchronous stream cipher and a keystream generator. The paper describes the main parts of the cryptosystem, its implementation and analysis of the statistical tests results for the keystream generator. Through its design and concepti...

The stream cipher Rabbit was first presented at FSE 2003 [5], and no attacks against it have been published until now. With a measured encryption/decryption speed of 3.7 clock cycles per byte on a Pentium III processor, Rabbit does also provide very high performance. Thus, the Rabbit design is currently submitted to the Ecrypt call for stream cipher primitives. This paper gives a concise descri...

The VMPC function is a combination of triple permutation composition and integer addition. It differs from a simple triple permutation composition with one integer addition operation performed on some of the elements of the permutation. The consequence of this addition operation is corruption of cycle structure of the transformed permutation the fundamental source of the function's resistance t...

Hermes8 [6,7] is one of the stream ciphers submitted to the ECRYPT Stream Cipher Project (eSTREAM [3]). In this paper we present an analysis of the Hermes8 stream ciphers. In particular, we show an attack on the latest version of the cipher (Hermes8F), which requires very few known keystream bytes and recovers the cipher secret key in less than a second on a normal PC. Furthermore, we make some...

In this paper we show how the synchronous stream cipher Edon80 proposed as a candidate stream cipher in Profile 2 of the eSTREAM project, can be efficiently upgraded to synchronous stream cipher with authentication. We are achieving that by simple addition of two-bit registers into the e-transformers of Edon80 core, an additional 160-bit shift register and by putting additional communication lo...

This paper discusses mixing of chaotic systems as a dependable method for secure communication. Distribution of the entropy function for steady state as well as plaintext input sequences are analyzed. It is shown that the mixing of chaotic sequences results in a sequence that does not have any state dependence on the information encrypted by them. The generated output states of such a cipher ap...

In this work a new algorithm for encryption image is introduced. This algorithm makes it possible to cipher and decipher images by guaranteeing a maximum security. The algorithm introduced is based on stream cipher with nonlinear filtering function. The Boolean function used in this algorithm is resilient function satisfying all the cryptographic criteria necessary carrying out the best possibl...

DICING is a synchronous stream cipher submitted to the ECRYPT stream cipher project. Two versions of the cipher actually exist: the first one can be found in the proceedings of the SKEW conference, while the second is available from the web site. In this paper we describe practical distinguishing and key recovery attacks against the first version. These attacks do not apply as such to the web s...

The Common Scrambling Algorithm (CSA) is used to encrypt streams of video data in the Digital Video Broadcasting (DVB) system. The algorithm uses a combination of a stream and a block cipher, apparently for a larger security margin. However these two algorithms share a common key. In this paper we present a fault attack on the block cipher which can be launched without regarding the stream ciph...