Encryption of binary images is essential since it is vulnerable to eavesdropping in wired and wireless networks. The security of data becomes important since the communications over open network occur frequently. This paper focuses on encryption of binary image using a stream cipher method. In this paper we propose an Ant Colony Optimization (ACO) based approach of generating keys for encryptio...

QUAD is a provably secure stream cipher, whose security is based on the hardness assumption of solving multivariate quadratic polynomial systems over a finite field, which is known to be NP-complete. However, such provable security comes at a price, and QUAD is slower than most other stream ciphers that do not have security proofs. In this paper, we discuss two efficient parallelization techniq...

1 Justification Shannon is a synchronous stream cipher with message authentication functionality, designed according to the ECrypt NoE call for stream cipher primitives, profile 1A (but well after the call). Shannon is named in memory of Claude E. Shannon[20] of Bell Labs and MIT, founder of Information Theory. Shannon is an entirely new design, influenced by members of the SOBER family of stre...

Decim is a hardware oriented stream cipher with 80-bit key and 64-bit IV which was submitted to the ECRYPT stream cipher project. The design of Decim is based on both a nonlinear filter LFSR and an irregular decimation mechanism called the ABSG. As a consequence, Decim is of low hardware complexity. Recently, Hongjun Wu and Bart Preneel pointed out two flaws in the stream cipher Decim. The firs...

In this paper, the hardware implementations of five representative stream ciphers are compared in terms of performance and consumed area in an FPGA device. The ciphers used for the comparison are the A5/1, W7, E0, RC4 and Helix. The first three ones have been used for the security part of well-known standards, especially wireless communication protocols. The Helix cipher is a recently introduce...

-In the today world, security is required to transmit confidential information over the network. Security is also demanding in wide range of applications. Cryptographic algorithms play a vital role in providing the data security against malicious attacks. But on the other hand, they consume significant amount of computing resources like CPU time, memory, encryption time etc. Normally, symmetric...

The aim of eSTREAM Profile II is to identify a small number of stream ciphers that are suitable for low resource circuitry based implementation. Besides algorithmic properties and security evaluation to theoretical attacks, performance evaluation is another important task of eSTREAM that is being considered. In this contribution we summarize and explain our testing framework for eSTREAM Profile...

In this paper we analyze the statistical distribution of the keystream generator used by the stream ciphers RC4 and RC4A. Our first result is the discovery of statistical biases of the digraphs distribution of RC4/RC4A generated streams, where digraphs tend to repeat with short gaps between them. We show how an attacker can use these biased patterns to distinguish RC4 keystreams of 2 bytes and ...

The paper introduces an abstraction in form of general conditions for cryptanalytic managing of the information about the current state of the RC4 stream cipher. The general conditions based strategy is used to favor more promising values that should be assigned to unknown entries in the RC4 table. The estimated complexity of the cryptanalytic attack is lower than the best published result alth...

Recently the first author presented exact formulas for the number of 2-periodic binary sequences with given 1-error linear complexity, and an exact formula for the expected 1-error linear complexity and upper and lower bounds for the expected k-error linear complexity, k ≥ 2, of a random 2-periodic binary sequence. A crucial role for the analysis played the Chan-Games algorithm. We use a more s...