State Convergence in the Initialisation of Stream Ciphers [chapter]

Sui-Guan Teo, Ali Al-Hamdan, Harry Bartlett, Leonie Simpson, Kenneth Koon-Ho Wong, Ed Dawson
2011 Lecture Notes in Computer Science  
An initialisation process is a key component in modern stream cipher design. A well-designed initialisation process should ensure that each key-IV pair generates a different keystream. In this paper, we analyse two ciphers, A5/1 and Mixer, for which this does not happen due to state convergence. We show how the state convergence problem occurs and estimate the effective key-space in each case.
doi:10.1007/978-3-642-22497-3_6 fatcat:yi47ibw6gjbdfbc4wiiup3dcou