Samir Al-Busaidi

A new algorithmic procedure to test m-sequence generating feedback connections of stream cipher's LFSRs

This paper presents a new algorithmic procedure for testing the feedback connections of an LFSR to check whether the design may generate maximal length sequences (m-sequence) or not. Since for an n-bit LFSR the algorithm only requires an (n-1)-bit register operation throughout its entire implementation, it requires minimal CPU time as well as memory space. Therefore, the attribute of the developed algorithm is two-fold. First, it is the fastest available algorithm and secondly, it does not pose a restriction on the length of the LFSR like other existing methods. The simulation results of the algorithm are compared with the results of existing algorithms and found to be much faster than the other existing algorithms. The implementation procedure of the algorithm is demonstrated through an elaborate example.