Cryptanalysis of hardware based stream ciphers and implementation of GSM stream cipher to propose a novel approach for designing n-bit LFSR stream cipher

With increasing use of network applications, security has become a major issue. Strong encryption mechanisms are required for securing important data. This encryption is provided by a strong cipher, capable of producing strong and highly random sequence of pseudo-random numbers. Through this paper, we present a detailed study of existing LFSR (Linear Feedback Shift Register) based hardware ciphers and an experimental approach to implement A5/1 algorithm on hardware platform. From this detailed study a generic cipher compatible with various network applications like smart cards, mobile phones, wireless LAN etc. has been proposed.