 However, an LFSR is a linear system, leading to fairly easy cryptanalysis.For example, given a stretch of known plaintext and corresponding ciphertext, an attacker can intercept and recover a stretch of LFSR output stream used in the system described, and from that stretch of the output stream can construct an LFSR of minimal size that simulates the intended receiver by using the Berlekamp-Massey algorithm.This LFSR can then be fed the intercepted stretch of output stream to recover the remaining plaintext.