In this paper we define a notion of leak extraction from a block cipher. We demonstrate this new concept on an example of AES. A result is LEX: a simple AES-based stream cipher which is at least 2.5 times faster than AES both in software and in hardware.

In 1980 Hellman introduced a general technique for breaking arbitrary block ciphers with N possible keys in time T and memory M related by the tradeoo curve T M 2 = N 2 for 1 T N. Recently, Babbage and Golic pointed out that a diierent T M = N tradeoo attack for 1 T D is applicable to stream ciphers, where D is the amount of output data available to the attacker. In this paper we show that a co...

Stream ciphers are an important class of encryption algorithms, which are widely used in practice. In this paper the security of the WAKE stream cipher is investigated. We present two chosen plaintext attacks on this cipher. The complexities of these attacks can be estimated as 10 and 10.

Nawaz, Gupta and Gong recently proposed a 32-bit RC4-like stream cipher. In this paper, we show that the keystream generated from their stream cipher is not random. The keystream can be distinguished from random with only about 100 outputs (3200 bits) in 2 milliseconds on Intel Centrino 1.6GHz processor.

In this paper we define a notion of leak extraction from a block cipher. We demonstrate this new concept on an example of AES. A result is LEX: a simple AES-based stream cipher which is at least 2.5 times faster than AES both in software and in hardware.

Generally, a stream cipher is a symmetric key cipher where plaintext bits are combined with a pseudorandom Keystream bits to achieve desired cipher text. In our paper, we are proposing a cryptosystem named Biometric-GaussianStream(BGS) cryptosystem. It is basically the combination of Gaussian noise and stream ciphers. In this system first, we pass an image through Gaussian noise function to add...

Secret key cryptography was traditionally divided into block ciphers and stream ciphers, but over the last 30 years the balance had steadily shifted, and today stream ciphers have become an endangered species. In this talk I'll survey the current state of the art in stream ciphers: who needs them, who uses them, how they are attacked, and how they can be protected by new types of constructions.