Resynchronization Weaknesses in Synchronous Stream Ciphers
نویسندگان
چکیده
In some applications for synchronous stream ciphers, the risk of loss of synchroniration cannot be eliminated completely. In these cases frequent rcsynchroniration or resynduonisation upon request may be necessary. In the paper it is shown that this can lead to significant deterioration of the cryptographic security. A powerful general attack on nonlinearly filtered linear (over Z,) systems is presented. This attack is further refined to efficiently cryptanalyze a linear system with a multiplexer as output function.
منابع مشابه
On a Resynchronization Weakness in a Class of Combiners with Memory
In some applications for synchronous stream ciphers frequent resynchronization or resynchronization upon request may be necessary. We describe a weakness in a class of combiners with one-bit memory which makes them vulnerable in such applications requesting resynchronization. A correlation attack based on chi-square criterion, which in some aspects complements the attack studied by Daemen et. a...
متن کاملExtending the Resynchronization Attack ( extended version ) ⋆
Synchronous stream ciphers need perfect synchronization between sender and receiver. In practice, this is ensured by a resync mechanism. Daemen et al. [9] first described attacks on ciphers using such a resync mechanism. In this paper, we extend their attacks in several ways by combining the standard attack with cryptanalytic techniques such as algebraic attacks and linear cryptanalysis. Our re...
متن کاملDifferential Power Analysis of Stream Ciphers
Side-channel attacks on block ciphers and public key algorithms have been discussed extensively. However, there is only sparse literature about side-cannel attacks on stream ciphers. The few existing references mainly treat timing [8] and template attacks [10], or provide a theoretical analysis [6], [7] of weaknesses of stream cipher constructions. In this paper we present attacks on two focus ...
متن کاملThe Filter-Combiner Model for Memoryless Synchronous Stream Ciphers
We introduce a new model – the Filter-Combiner model – for memoryless synchronous stream ciphers. The new model combines the best features of the classical models for memoryless synchronous stream ciphers – the Nonlinear-Combiner model and the Nonlinear-Filter model. In particular, we show that the Filter-Combiner model provides key length optimal resistance to correlation attacks and eliminate...
متن کاملExtending the Resynchronization Attack
Synchronous stream ciphers need perfect synchronization between sender and receiver. In practice, this is ensured by a resync mechanism. Daemen et al. [10] first described attacks on ciphers using such a resync mechanism. In this paper, we extend their attacks in several ways by combining the standard attack with cryptanalytic techniques such as algebraic attacks and linear cryptanalysis. Our r...
متن کامل