A key recovery attack on the stream cipher Achterbahn128/80, a cipher in the second phase of eSTREAM, is given. The key observation is a high dependency between some input bits to the Boolean combining function generating the keystream. It results in the first known attacks on both the 128-bit and the 80-bit variants of the cipher. The amount of keystream bits required in the attacks is less th...

Achterbahn is one of the stream cipher proposals in the eSTREAM project. After the first version had been successfully cryptanalyzed, the second version, denoted Achterbahn-Version 2, was proposed. This paper demonstrates an attack on this second version. In the attack, a quadratic approximation of the output function is considered. The attack uses less keystream bits than the upper limit given...

This paper compares the software speeds of 128-bit 10-round AES, 256-bit 14-round AES, 256-bit CryptMT v3, 256-bit Dragon, 128bit HC-128, 256-bit HC-256, 128-bit LEX v1, 128-bit NLS v2, 128bit Rabbit, 256-bit RC4, 256-bit Salsa20/8, 256-bit Salsa20/12, 256-bit Salsa20/20, 256-bit SNOW 2.0, 256-bit Sosemanuk, and 80-bit TRIV-

Scan chains, a design for testability (DFT) feature, are included in most modern-day ICs. But, it opens a side channel for attacking cryptographic chips. We propose a methodology by which we can recover internal states of any stream cipher using scan chains without knowledge of its design. We consider conventional scan-chain design which is normally not scrambled or protected in any other way. ...

Stream ciphers are fast cryptographic primitives to provide confidentiality of electronically transmitted data. They can be very suitable in environments with restricted resources, such as mobile devices or embedded systems. Practical examples are cell phones, RFID transponders, smart cards or devices in sensor networks. Besides efficiency, security is the most important property of a stream ci...

A few lightweight stream ciphers were introduced for hardware applications in the eSTREAM project. In FSE 2015, while presenting a new idea (i.e. the design of stream ciphers with the shorter internal state by using a secret key, not only in the initialization but also in the keystream generation), Sprout was proposed. Unfortunately, Sprout is insecure. Because Grain-v1 is the lightest cipher i...

Stream cipher Edon80 [6] is one of the submissions to the ECRYPT Stream Cipher Project eSTREAM that passed to the Phase II of this project. The core of this cipher is based on pipelined quasigroup transformations using the so called e-transformers [6]. We study algebraic properties of the suggested quasigroups for use in the stream cipher Edon80 and prove that all the suggested quasigroups for ...

Rabbit stream cipher is one of the finalists of eSTREAM project which uses 128-bit secret keys. Prior to us, the attacks on Rabbit has been all focused on the bias analysis and the best result showed the distinguishing attack with complexity 2. Our analysis in this paper, is based on chosen IV analysis on reduced N-S round of Rabbit though using multi cube tester. For this purpose we show for a...