Stream ciphers are vulnerable to generic time-memory-data tradeoff attacks. These attacks reduce the security level half of cipher’s internal state size. The conventional way handle this vulnerability is design cipher with an twice as large desired level. In lightweight cryptography and heavily resource constrained devices, a size big drawback for cipher. This principle can be found in eSTREAM ...

Sosemanuk is a software-based stream cipher which supports a variable key length of either 128 or 256 bits and 128-bit initial values. It has passed all three stages of the ECRYPT stream cipher project and is a member of the eSTREAM software portfolio. In this paper, we present a fault analysis attack on Sosemanuk. The fault model in which we analyze the cipher is the one in which the attacker ...

Rabbit is a high speed scalable stream cipher with 128-bit key and a 64-bit initialization vector. It has passed all three stages of the ECRYPT stream cipher project and is a member of eSTREAM software portfolio. In this paper, we present a practical fault analysis attack on Rabbit. The fault model in which we analyze the cipher is the one in which the attacker is assumed to be able to fault a ...

In today's world the use of computer and telecommunications networking is essential for human life. Among these, mobile tools and devices due to availability, have found a special impact on everyone life. This feature addition to providing sample facilities such as financial transactions at any place and time has raised the Sensitivities about security of these devices. In order to provide secu...

Pomaranch is a synchronous bit-oriented stream cipher submitted to eSTREAM, the ECRYPT Stream Cipher Project. Following the recently published chosen IV [1] and correlation [7] key-recovery attacks, the authors changed the configuration of jump registers and introduced two new key-IV setup procedures for the cipher. We call the updated version as Tweaked Pomaranch vs. Original Pomaranch [4]. In...

NLS is one of the stream ciphers submitted to the eSTREAM project. We present a distinguishing attack on NLS by Crossword Puzzle (CP) attack method which is newly introduced in this paper. We build the distinguisher by using linear approximations of both the non-linear feedback shift register (NFSR) and the nonlinear filter function (NLF). Since the bias of the distinguisher depends on the Kons...

In this paper we present a rather new approach to apply mixed-integer optimization to the cryptanalysis of cryptographic primitives. We focus on the stream cipher Trivium, that has been recommended by the eSTREAM stream cipher project, and the lightweight block cipher Ktantan. Using these examples we explain how the problem of solving a non-linear multivariate Boolean equation system can be for...

In this paper we present experimental results of an application of SAT solvers in current cryptography. Trivium is a very promising stream cipher candidate in the final phase of the eSTREAM project. We use the fastest industrial SAT solvers to attack a reduced version of Trivium – called Bivium. Our experimental attack time using the SAT solver is the best attack time that we are aware of, it i...

This paper presents hardware implementation and analysis of a carefully selected sub-set of the candidate stream ciphers submitted to the European Union eStream project. Only the submissions without licensing restrictions have been considered. The sub-set of six was defined based on memory requirements versus the Advanced Encryption Standard and any published security analysis. A number of comp...

In stream cipher cryptography a pseudorandom sequence of bits of length equal to the message length is generated. This sequence is then bitwise XORed (addition modulo 2) with the message sequence and the resulting sequence is transmitted. At the receiving end, deciphering is done by generating the same pseudorandom sequence and bitwise XORing the cipher bits with the random bits. The seed of th...