When a stream cipher is referred to a synchronous, what does this mean? 2. How do the encryption and decryption operations differ in a binary additive synchronous stream cipher? What is the implementation advantage associated with this? For a Linear Feedback Shift Register (LFSR) of length L, a. What is maximum period of the LFSR output sequence? b. What is required to obtain a sequence of maximal length? c. What is the linear complexity of a maximal length LFSR output sequence? Describe two methods to produce a binary output sequence using LFSRs with increased linear complexity. Consider the LFSR shown in the diagram above: a. Using the initial state indicated, produce the first 40 terms of the LFSR output sequence. b. What is the period of the LFSR output sequence? c. Is this maximal