Say we have M as message bits , why do we need to append r-zeros to M message bits before performing the division to obtain r-bit checksum. Why don't we directly perform the division on the M message ...
Can every periodic binary sequence be expressed as the output of a Linear or Non-Linear Feedback Shift Register?
Quick background: The output of a Linear Feedback Shift Register (LFSR) with $n$ taps is a binary sequence which is periodic of length dividing $2^n-1$. From a mathematical point of view, such a ...
I'm reading the source code of a stream cypher (zuc): I cannot understand properly why they define the multiplication by power of 2 in this way: ...